-*- mode: text; mode: fold -*-
Changes since 2.0.7
1. src/slrline.c: SLrline_bol/eol functions were missing from the
   interface.
2. src/slarray.c: An optional reference argument may be passed to the
   where function to get the complement indices.  That is:
   
       i = where (foo, &j);
   
   is equivalent to 

       i = where (foo); 
       j = where (not foo);

3. src/slexcept.c: SLerr_throw added to allow applications to mimic
   the semantics of "throw".
4. src/slparse.c,slang.c: New short-circuit operators || and &&.  Use
   of the "orelse" and "andelse" constructs has been deprecated.
5. src/slsmg.c: SLsmg_write_wrapped_string and SLsmg_write_nstring
   were broken for double-width characters.  Updated demo/smgtest.c to
   test these functions in the presence of such characters.
6. demo/smgtest.sl: Embedded some control characters in the
   double-wide character string for testing the handling of them.
7. doc/tm/cslang.tm: Updated some of the documentation for the SLsmg
   interface.
8. src/slstd.c,slang.c: Added new function intrinisc called "_$" that
   expands embedded "dollar-escaped" variables.
9. src/sllist.c: Added __push_list/__pop_list functions that push list
   elements to the stack or create a list from objects on the stack.
   These functions may also be used as an alternative to
   __push_args/__pop_args.
10. slsh/lib/structfuns.sl: Modified struct_combine to use __pop_list
    instead of __push_list.
11. src/test/scircuit.sl used for regression testing of the
    short-circuit operators was missing.
12. src/slang.c: Small memory leak involving method calls plugged.
13. src/slparse.c,slang.c,slstruct.c: Added support for embedded
    assignments in structure definitions, e.g.,
    
        X = struct { a = 4, b = 3, c = sin(PI/4)};

14. src/slang.c,slparse.c,slstruct.c: Added support for
    "function-qualifiers", e.g,.

         define plot_point (x, y)
	 {
	     set_color (qualifier ("color", "black"));
	       .
	       .
	 }
	 plot_point (2, 1; color="red");

   See docs for more info.
15. modules/png.sl: Added gmin and gmax qualifiers to the
    png_gray_to_rgb function.
16. src/kwhash.c: New keywords: "ifnot" and "then".  The "ifnot"
    keyword plays the same role as "!if", except the use of "!if" is
    deprecated.  Then "then" keyword is used in looping constructs as
    described in #17.
17. src/slparse.c,src/slang.c: All looping constructs may be followed
    either an "else" block, or a "then" block, or a combination of
    both:
           loop (N)
	     {
	        if (foo) 
		  break; % execute the else block if present
	     }
	   then 
	     { 
	        % This block executes if the loop ran to completion
	     }
	   else
	     {
	        % This block executes if the loop was broken prematurely
	     }
	     
    *** NOTE: This change broke backward-compatibility.  For this
    reason, support for the else clause was dropped".  See #48 below.

18. slsh/scripts/slprof: Rewrote much of this script to make it more
    friendly and useful.
19. src/sldisply.c: When checking for the equality of space
    characters, it is only necessary to see see if their background
    colors are equal -- the foreground color does not matter.
    Miroslav Lichvar mlichvar at redhat, com.
20. modules/png.sl: A variable (bad_level) was undefined.
21. src/slparse.c: The meaning of constructs such as (a<b<c) has been
    changed to have its mathematical meaning, namely ((a<b)and(b<c)).
    Before, (a<b<c) was interpreted as (a<b)<c.  Also, == and != now
    have the same precedence level as <,<=,>,>= to permit, e.g.,
    (a==b<c).  Note that (a<b<....<c<d) is also defined as 
    ((a<b)and(b<...<c)and(c<d).
22. src/slarray.c: New intrinsic: wherenot(x), which means where(not x).
23. src/slarray.c,slparse.c: [a:b:#n] may be used to specify a
    floating point array with n elements running from a to b, inclusive.
24. src/slparse,slang.c: Fixed the bug where _NARGS was incorrectly
    set in functions called via expressions such as (@A[i])(x).
25. src/slang.c,slarray.c,slparse.c,slstruct.c: References to
    structure fields and array elements are now supported, e.g.,
    &s.foo and &A[20].
26. slsh/slsh.c: Added '-e string' command-line option.
27. slsh/lib/profile.sl: Rewrote much of it to support both profiling
    individual lines and functions.
28. slsh/scripts/slprof: Added 'calibrate' and 'lines' command-line
    options.
29. src/slang.c: Unsigned ints were sometimes pushed as signed ints.
30. src/slrline.c: Added a new public function called SLrline_move
    that moves the cursor a specified number of columns.
31. slsh/lib/glob.sl: If a glob pattern does not include a path, the
    returned list of files will nolonger be prefixed with "./", i.e.,
    glob("foo") returns "foo" and not "./foo".
32. slsh/readline.c: If slsh_interactive_hook exists, it will be
    called prior to going into interactive mode.
33. src/slrline.c:  A completion mechanism was added.  This works by
    making a callback to a user or application provied hook that
    returns a list of possible completions.  This functionality is
    available if SLrline_init has be called to add readline-specific
    intrinsics to the interpreter.  The slang code implementing the
    completion hook is in slsh/lib/complete.sl.
34. modules/png.sl: Load the colormaps into the same namespace that
    was used by png.sl (Mike Noble).
35. slsh/slsh.c: readline intrinsics were not getting initialized.
36.  slsh/lib/rline/completion.sl: Avoid adding NULL to the completion
    list when no completions are in the global or current namespace.
37. src/slerr.c: Added SLang_verror_va function. It is like
    SLang_verror, except it takes a va_list argument instead of a
    variable argument list.
38. slsh/scripts/slprof: If atexit exists, use it.
39. src/slwclut.c: Typo in is_posix_charclass (> instead of >=) was
    causing the long form of posix character class names not to be
    properly recognized.
40. src/slrline.c: SLrline_init was using SLfree instead of
    SLang_free_slstring, causing a core-dump.
41. slsh/lib/slshrl.sl: Use slsh_get_doc_string defined in slshhelp.sl.
42. autoconf/aclocal.m4: Add support for rpath on OpenBSD.
43. src/slarray.c: Single element arrays specified via, e.g., [a:b:#1]
    produced the array [b] instead of the "more" correct answer [a].
44. src/slexcept.c: __get_exception_info will NULL if no exception is
    active.  Previously it reported an unknown exception.
45. src/slang.c: If a finally-block threw an exception and then caught
    it, the outer exception was getting lost.
46. slsh/lib/glob.sl: glob("*") nolonger matches files that begin with
    ".".  A leading dot in a filename must be matched explicitely.  A
    similar change was made to glob_to_regexp.
47. src/slang.c,src/slexcept.c: An exception may be rethrown by using
    "throw" without any arguments.  This required support for multiple
    error-queues.
48. src/slparse.c: The "loop-else" feature added in change #17 was
    dropped because the change was not backwards compatible, changing
    the meaning of connstructs such as
    
           if (some_condition)
	     loop (N) {...}
	   else
	     something_else();

    "loop-then" is still supported.  (Thanks go to Paul Boekholt for
    picking up on this).
49. src/sldisply.c: If the terminal supports BCE, then ignore the
    background color of space characters that occur as trailing
    whitespace (Miroslav Lichvar).
50. src/slrline.c: Added additional rline intrinsic functions:

      rline_call
      rline_set_point
      rline_set_line

51. src/slrline.c:   SLrline_init was using SLang_free_slstring
    instead of SLfree.  Also SLrline_set_point was using < instead of
    > when comparing point to len.
52. src/slrline.c: Added rline_getkey and rline_input_pending
    intrinsic functions.
53. src/slstd.c: If the "char" function is passed a negative integer,
    byte-semantics will be used.
54. src/slrline.c: When browsing previous history items, the item that
    is currently being edited will not be lost.
55. src/slrline.c: A new function called SLrline_open2 was added to
    the API.  It is like SLrline_open except that it associates a name
    with the underlying SLrline_Type object and calls an interpreter
    hook (rline_open_hook)  with that name.  This mechanism permits
    the readline history to be saved to a file and then later retrieved.
56. slsh/lib/rline/*.sl: A few .sl files were added:
      vikeys.sl:    A simple vi-like emulation
      emacs.sl:     A emacs-like emulation
      editfuns.sl:  Some utility editing functions
      history.sl:   Functions to save/restore history
57. slsh/scripts/sldb: If the file was specified using a relative
    path, prefix its name with the cwd to ensure that it loads.
58. src/slmath.c: Add "fuzzy" floating point comparison functions
    feqs, fneqs, flteqs, fgteqs, which compare numbers using a
    specified relative and absolute error.
59. slsh/readline.c: Readline objects were made available to the
    interpreter.
60. slsh/scripts/svnsh, slsh/lib/sldb.sl: Added readline-specific
    calls to enable the saving/loading of history.
61. src/slrline.c: Added rline_get_edit_width intrinsic.
62. src/slarrfuns.c: prod function added (Mike Noble).
63. src/slstrops.c: %b may be used in sprintf to specify a byte
    conversion.  This is equivalent to %c when UTF-8 mode is not in
    effect.
64. src/slarrfuns.c: PROD_RESULT_TYPE was not getting defined on 64
    bit systems (Brian McQueen)
65. src/Makefile.in,autoconf/Makefile.in: Now `make install` installs
    the shared library but not the static one.  Use `make
    install-static` to install the static one.
66. autoconf/aclocal.m4: rpath support for netbsd
67. slsh/slsh.c: A preprocessor symbol may be added using -Dname
    command-line option.
68. src/slstd.c: changed __is_numeric to return 1 if an integer, 2 if
    a floating point, and 3 if complex.
69. src/slang.c: missing break statement in the handling of the
    qualifier token.  This bug manifested itself only when running
    with slprof or sldb.
70. slsh/lib/cmdopt.sl: Functions to facilitate the processing of
    command line options.
71. slsh/scripts/slprof: modified slprof to use the cmdopt interface.
72. slsh/lib/structfuns.sl: Enhanced the struct_filter function to
    filter on specific array dimensions and to return a new structure
    when given the "copy" qualifier.
73. src/slimport.c: Allow pathname in an import statement, e.g.,
    import("/path/to/module");
74. src/slarrfun.c: Added minabs/maxabs functions.
75. lib/cmdopt.sl: Added support for type="str" qualifier.  Also,
    cmdopt documentation corrected.
76. src/slassoc.c: When resizing an associative array that had
    elements deleted, the num_occupied field was not being properly
    updated.  This was causing the length of the array to be
    incorrectly computed.
77. src/slproc.c: Added getpgrp,setpgrp,getgid functions.
78. src/slutty.c: In the getkey function, if a SIGINT caused
    SLKeyBoard_Quit to be a non-zero value, the interrupt_hook was not
    getting executed.
79. autoconf/Makefile.in: Tell the user to re-run the configure script
    if it is more recent than the Makefile.
80. src/slstd.c: __is_numeric was not returning 3 for Complex_Type.
81. src/slexcept.c: Do not log traeback messages unless _traceback is
    non-zero.
82. src/slclass.c: Added SLclass_patch_intrin_fun_table to the library
    and modified the code in modules/ to make use of this function.
83. src/slang.c: SLang_Traceback is now a bitmapped variable, but
    defined in a backward compatible manner.  See slang.h and the
    documentation for the _traceback variable for more information.
84. src/slang.c,slexcept.c: Change 83 required a small tweak to the testing of
    traceback variable.
85. src/slparse.c: MAX_TOKEN_LISTS increased to 256.
86. src/slparse.c: Added a couple of #if..#endif constructs to avoid
    compiling bos/eos hooks when the debug feature has been disabled.
    (Tijs Michels tijs, michels at t-online, de)
87. src/slproc.c: The setpgrp function that was added in change #77
    has been removed because on some systems it takes arguments, and
    on others it takes none.  It is also equivalent to setpgid(0,0),
    so there is no net loss.
88. src/slutty.c: Set the FD_CLOEXEC flag on the /dev/tty file
    descriptor.
89. src/doc/tm/cslang.tm: Changed the array examples to use
    `SLindex_Type' instead of `int'.  I also added a note about this
    to the NEWS file.
90. modules/iconv-module.c: a new module (Dino Sangoid).
91. src/slsig.c: SLsignal was used instead of SLsignal_intr.  The
    difference is that SLsignal_intr interrupts system calls, which is
    a better choice for the interpreter.
92. src/slproc.c: added setsid intrinsic
93. src/slarray.c: [a:b:#1] was producing [NaN] instead of [a].
94. src/sldbcore.c: The debugger was not stopping upon SIGINT.
95. src/sltermin.c: Added _pSLtt_tifreeent to free the SLterminfo_Type
    object and avoid a memory leak (Miroslav Lichvar
    mlichvar at redhat, com)
96. slsh/lib/cmdopt.sl: Add bor=FLAG and band=MASK qualifiers to support
    bitmapped options.
97. modules/onig-module.c: New module that wraps the oniguruma regular
    expression library.
98. src/slang.c: If a file defining a namespace was loaded, a
    duplicate namespace error was getting generated when also loading
    a byte-compiled version of the same file.
99. src/slclass.c: In _pSLclass_copy_class, a possible NULL return
    value by alloc_class_slot was not being handled.

{{{ Previous Versions

Changes since 2.0.6
1. src/slmath.c: if a double precision array was passed to nint, it
   was treated as a single precision one leading to a core dump.
2. src/sldisply.c: The Is_Fg_BGR variable was re-introduced and a typo
   affecting it was corrected.
3. src/slinclud.h: Do not include malloc.h on FreeBSD (Renato Botelho
   garga at freebsd, org).
4. doc/tm/cslang.tm: Changed a couple of occurances of "unsigned char"
   to "SLtype".  (Doug Burke dburke at head, cfa, harvard, edu)
5. doc/tm/rtl/list.tm:  Documentation changed to indicate that the
   third parameters to list_append/insert are optional.  (Doug Burke).
6. src/slwcwidth.c: Added a new function to the API called
   SLwchar_set_wcwidth_flags.  This may be used to force
   SLwchar_wcwidth to 1 for double width characters.  Such a feature
   is sometimes needed for fixed fonts that treat single and double
   width characters the same.
7. slsh/lib/slshrl.sl: The readline-massage hook was interpreting
   lines beginning with a '.' as RPN.
8. slsh/lib/sldb*.sl: The debugger was not stopping upon errors
   generated by the deprecated function verror.
9. src/slparse.c: "++()" was flagged by the parser as an error, but no
   error message for it was being generated.
10. src/slang.h: #if HAVE_LONG_LONG changed to #ifdef HAVE_LONG_LONG
11. src/slsmg.c:  Return right away if SLsmg_write_chars is told to
    write 0 characters.  Also a bug fixed in the logic of this routine
    involving the test for overwriting the second half of a double
    width character.
12. src/slrline.c: Finished the UTF-8 support by the readline functions.
13. slsh/*.c: Added slsh_get/set_prompt_hook functions for setting of
    the slsh command-line prompt.  (Douglas Burke)
14. src/sltoken.c: Added additional string representations for tokens
    so that some error messages will not appear to be so cryptic.
15. src/sltoken.c: _pSLparse_error: Use the line number of the input
    stream if the linenumber associated with a token is unknown.
16. src/slparse.c: Inline arrays and lists are allowed to have a
    trailing comma, e.g., [1,2,] is the same as [1,2].
17. doc/tm/rtl/type.tm:  typo in example for atof corrected (Doug
    Burke).
18. Improvements for building on DOS/Windows (Mike Noble):

      * The various mkfiles/makefile.all now include a clean: target
      * The top-level mkfiles directory now includes 3 new files:
  
  	   A build.sh script, which auto-generates the Makefiles
	   (using mkmake) and commences a build, similar to the
	   build.bat script which was already there (and which I
	   tweaked slightly).

  	   Seed makefile.dos and makefile.sh scripts, which get copied
	   to the root of the S-Lang distro when either build.sh or
	   build.bat are run.  This makes it easier to build
	   everything at once, or clean, etc, from the top of the
	   distro.

      * A few new paragraphs in INSTALL.pc
      * In the various mkfiles/makefile.all, "CFLAGS +=" changed to
	"CFLAGS =" to avoid nmake 1.5 problems.
      * Simplified the module build targets in modules/makefile.all,
	and made it much easier to add new modules in the future.
19. Added module support for cygwin.  This involved a few minor
    changes to the Makefiles and aclocal.m4  (Mike Noble)
20. slsh/slsh.c: Brief copyright message displayed when started up in
    interactive mode.
21. src/slarray.c: Improved support for mixed-type inline arrays:
    NULLs supported (["foo", NULL]) where it makes sense, and
    type-promotion rules are used to determine the resulting type when
    concatenating mix-type arrays (["foo"], NULL, ["bar\0"]);
22. src/slrline.c: SLrline_close was not freeing the history creating
    a memory leak.
23. src/keywhash.c: Removed obsolete and unused "do_while" keyword,
    and regenerated keywhash.c
24. doc/tm/slang.tm: List of keywords updated to reflect the actual
    keywords used.
25. modules/mkfiles/makefile.all: Updated VC-specific LINK_CMD macro
    to support the changes outlines in 18 above (Dino Sangoid).
26. src/slang.c,src/slboseos.c: Added hooks for entering and leaving a
    function.  The beginning-of-statement and end-of-statement hooks
    were found insufficient to support a debugger support.  See the
    documentation for _bofeof_info for more information.
27. slsh/lib/sldbcore.sl: Modified to use the bof/eof hooks introduced
    in #26.
28. Various documentation tweaks.
29. src/slboseos.c: Changed the beginning-of-function handler to
    include the filename.
30. src/slsh/lib/require.sl: Removed the "feature not provided" message.
31. src/slrline.c: Tabs were not being expanded properly when the
    window was horizontally scrolled.  Also, the last column of the
    display is not used in case the terminal has automatic margins.
32. lib/sldbcore.sl: The debugger's "finish" command was not quite
    working as it should have.
33. lib/sldbcore.sl: Added an sldb_initialize function that can be
    overridden by the debugger.
34. src/slposio.c: Made changes to allow arbitrary objects to be
    attached to file descriptors.
35. src/sl*tty.c: Set SLKeyBoard_Quit to 0 in the init_tty routines.
36. modules/socket-module.c: A new module that defines various socket
    functions.  This required additions to the configure script and
    related files.
37. src/slstrops.c, slsh/readline.c: Removed statements that were never
    reached.
38. src/sltypes.c: foreach(X) where X is String_Type produces a
    sequence of UChar_Type objects.  This is consistent with
    typeof(X[i]).  Also added "using" forms to specify char or
    byte-semantics: foreach (X) using ("bytes"|"chars").  The default
    is byte semantics.  Updated the corresponding docs.
39. src/slang.h: Added SLang_push/pop_wchar macros.
40. src/sldisply.c: This file was failing to compile with Kanji
    support enabled.  Kanji is unsupported in slang-2.
41. src/slcurses.*: Alt-character set handling was not working.  Once
    again, I strongly encourage you to modify your programs to use the
    native SLsmg routines instead of the partial curses emulation hacks.
42. slsh/lib/sldbsock.sl: New file to implement socket-based debugger.
43. slsh/scripts/sldb: Added --pid <pid> option for debugging a
    separate process via the socket-based debugger interface.
44. src/slang.c: If a try-finally block contained a return statement,
    the function would sometimes continue after the finally block.
45. modules/termios-module.c: Added tcget/seti/ospeed functions for
    setting baudrates of termios structures.  Also added CRTSCTS
    constant to the module.
46. src/slclass.c: If an application calls SLang_pop_mmt with a
    non-MMT type specified, a SL_Application_Error exception will be
    generated.
47. src/slang.c: A misplaced return statement was introduced by #44
    above.
48. src/slparse.c: Allow the "finally" keyword to be followed by a
    colon, e.g., try foo; finally: bar;
49. src/sltoken.c,slang,c: "Dollar" and long-longs were not being properly
    handled in byte-compiled files.
50. src/test/Makefile: Changes were made to test byte-compiled
    versions of the test scripts.
51. modules/socket-module.c: added #include <time.h> to get it to
    compile on mac osx.
52. src/slmath.c: The data field was not properly used by the nint function.
53. modules/select-module.c: Call SLang_handle_interrupt when the
    select system calls gets interrupted.
54. src/slposio.c: Add == and != operators to FD_Type objects so that
    fileno(stdin)==fileno(stdin) works as expected.
55. src/slarray.c: wherefirst and wherelast were not working with
    empty arrays.
56. src/slmisc.c: SLang_guess_type was failing on numbers containing a
    leading '+' sign.
57. src/slimport.c: The name of the SLANG_MODULE_PATH environment
    variable may be changed in src/Makefile.
58. src/slrline.c: Added a delete-to-beginning-of-line (delbol)
    function and bound it to ^U.
59. slsh/Makefile.in: $(CFLAGS) added to the final link line. (Nelson
    H. F. Beebe)
60. src/slmath.c: Avoid the use of function pointers to standard math
    functions to support a wider range of compilers.
61. autoconf/aclocal.m4: IRIX compilers do not require "-K pic"
62. autoconf/configure.ac: Probe for socklen_t.
63. */Makefile.in: Added support for the $LIBS env variable
64. src/slerr.c: Added fflush(stdout) to SLang_vmessage.
65. slsh/lib/sldbcore.sl: The eof hook was improperly handling the
    debugger step.
66. src/slarray.c: Optimization added for index-array operations on
    double, float, and int arrays.
67. src/slarith.c: Optimization added for boolean operations between
    [U]Char_Types.
68. lib/structfuns.sl: Typo in the documentation corrected (Doug Burke)
69. lib/*.sl, lib/tm/*.tm, lib/help/*.hlp: Documentation for the
    functions in *.sl has been moved to *.tm and integrated into the
    help system.
70. src/slwclut.c: a missing "default" label in a switch statement was
    causing invalid character class specifiers to pass.
71. src/slang.c: Optimization added for struct method calls.  In
    addition, linenumber information was propagated for such function
    calls to permit better interaction with the debugger.
72. slsh/lib/profile.sl: profile_on was not being called with an
    argument.

Changes since 2.0.5
1. src/slmath.c: nint was returning the wrong value for numbers 0.5<=x<1.
2. src/slarrfuns.c: sum(Double_Type[0,0],1) was generating an access
   error.
3. src/*.c: Removed some unused variables.
4. src/slcommon.c: '=' instead of '==' was being used in the
   utf8_enable function.
5. doc/tm/*.tm: corrected some documentation typos (Nelson Beebe,
   beebe at math, utah, edu).
7. src/sltime.c: times function was returning a structure containing
   incorrect values (cstawarz at head, cfa, harvard, edu).
8. src/sldisply.c: Writing a multi-byte character to the lower-right corner 
   of terminals with automatic margins was not working (Vladimir
   Nadvornik nadvornik at suse, cz).
9. src/slwclut.c: Allow \\^ in character set specifications to
   represent a literal '^'.  See the documentation for strtrans for
   more information.
10. src/slcommon.c: Some systems that have nl_langinfo do not have
    CODESET.  The configure script now checks for both.
11. autoconf/Makefile.in: Added ".PHONY" and "check" targets.
12. src/slstrops.c: "%c" in an sprintf style format descriptor made to
    work with wide-character arguments.  It is nolonger necessary to
    use "%lc".
13. src/slmisc.c: Semantics of "\x{...}" changed to be more useful
    when the interpreter is running in non-UTF8 mode.  Previously,
    "\x{...}" always expanded to a UTF-8 encoded string, regardless of
    the UTF-8 mode.  Now, in non-UTF8 mode, \x{...} will expand to a
    UTF-8 encoded string when "..." consists of 3 or more characters,
    and for less than 2 characters, it specifies a byte.  The behavior
    in UTF-8 mode has not changed: \x{...} always returns a UTF-8
    encoded string.  The upshot is that "\x{FF}" will produce the byte
    0xFF when not in UTF-8 mode, and the 2 byte UTF-8 encoding when
    run in UTF-8 mode. "\x{FFF}" will expand to the apropriate UTF-8
    encoding regardless of the mode.  Note that the behavior of the
    non-brace form such as \xAB has not changed--- the result is still
    a single byte 0xAB.
14. src/slmisc.c: \u{...} may be used in string literals to specify a
    unicode character, regardless of the UTF-8 mode (on or off).
    Previously, \x{...} had this behavior. (See #13).
15. src/test: Tests are run in both UTF-8 and non-UTF-8 modes.
16. src/slvideo.c: djgpp version of write_attributes was broken (Gisle
    Vanem giva at bgnett, no)
17. slsh/readline.c: Call SLang_handle_interrupt if a read was
    interrupted by a signal.  This will ensure that signal handlers
    will execute at the prompt.
18. src/sldisply.c: Added a check for buffer-overflow by tgetstr on TERMCAP
    based systems.
19. autoconf/: Updated config.sub and config.guess
20. slsh/readline.c: Added slsh_readline_noecho function.  Also, strip
    trailing newline from string returned by slsh_readline* when in
    --no-readline mode.

Changes since 2.0.4
1. slsh/slsh.c: Error messages were not being printed if an error
   occured during an atexit hook.
2. src/slstrops.c: Use _pSLstring_bytelen instead of strlen to get the
   number of bytes.
3. src/slstring.c: Several tweaks were made for faster string handling.
4. src/slparse.c: A negative integer literal raised to a power was not
   being properly parsed.
5. doc/tm/cslang.tm: Documentation updated to reflect the changed
   SLang_pop_double API, as well as other C API documentation
   tweaks (Doug Burke).
6. doc/tm/rtl/type.tm: Documentation for "integer" changed to indicate
   that integer throws a SyntaxError exception if the string does not
   have a valid syntax. (Joshua Kempner jkempner at bowdoin, edu)
7. src/slmath.c: Added nint (round to the nearest integer) intrinsic.
8. src/slarray.c: NULL arguments to array_map were not getting
   converted to arrays of NULL.
9. src/slang.h: Added SLclass_set_length_function for setting the
   length method of application-defined classes.
10. src/slang.ver: A versioning script is used to restrict the
    visibility of the _pSL* symbols.  (Alastair McKinstry
    mckinstry at computer, org)
11. slsh/slsh.c: Ignore SIGPIPE.
12. src/slutf8.c: If SLutf8_decode is passed an inproperly encoded
    UTF-8 sequence, then set the target of the SLwchar_Type pointer to
    the ascii value of the byte, in addition to returning NULL.
13.  src/slposdir.c: Added "access" intrinsic.
14. src/slsmg.c: Fixed a buffer-overflow in the SLsmg_write_chars
    function.
15. src/slsig.c: A missing return statement was causing sigsuspend to
    fail when called with 0 arguments.
16. src/slarray.c: Added wherefirst and wherelast intrinsics.
17. src/slang.c: Inline attribute removed from some functions that
    were failing to be inlined by the compiler.
19. src/slstdio.c: SLang_get_fileptr added to permit an application to
    get the FILE* object associated with a SLANG_FILE_PTR_TYPE.
20. src/slang.c: It was failing to compile when
    SLANG_HAS_DEBUGGER_SUPPORT was set to 0.
21. src/sltime.c: strftime intrinsic added.

Changes since 2.0.3
1. slsh/scripts/svnsh: Empty lines were not being handled.
2. src/slutf.c: Incorrect bracketing in the IS_ILLEGAL_UNICODE macro.
   (johannes figgen at flextronicssoftware, com)
3. src/sllist.c: A prev link was not always getting set by the list_insert
   function.
4. doc/tm/rtl/eval.tm: Tweaked the documentation for the eval function
   (Mike Noble mnoble at space, mit, edu)
5. modules/png.sl: Make sure the scale factor is a float and not an int.
6. src/sltime.c: The tic/toc functions were changed to use
   gettimeofday or its equivalent.  This change results in greater resolution
   for these interval timers, but not necessarily greater accuracy.
   Also, previously the tic/toc functions measured the time used by
   the current process but now they measure elapsed time.  The old
   behavior is still available via _tic/_toc.
7. slsh/lib/profile.sl: The above change made it possible to create a
   more accurate profiling tool.  The functions in this file are used
   by the slsh/scripts/slprof profiling tool.
8. src/slarith.c: Missing break statement caused signed long long
   values to be printed as unsigned long longs.
9. tm/doc/cslang.tm: Two small typos corrected (Alastair McKinstry
   mckinstry at computer, org)
10. autoconf/aclocal.m4: Support for GNU Hurd and GNU KFreeBSD /
    KNetBSD systems (Alastair McKinstry)
11. src/slstrops.sl: Added support for long long to the sprintf
    intrinsic function (e.g., sprintf ("%lld", 1234LL))
12. modules/png-module.c: 8 bit gray scale images were being written
    out as 8 bit images with an alpha channel.  Bug fixed and version
    bumped to 0.1.1.

Changes since 2.0.2
1. src/slang.c: Optimization of multiple assignment statements involving
   binary operators was generating bad byte-code causing a run-time
   error.  In order to see this effect, code such as 
   
        w = 3*t+s;
        x = 2*z+1;
	y = z*z;
	
   would have to be written as a as multiple assignment statement:
   
        (w,x,y) = (3*t+s, 2*z+1, z*z);

2. src/sltypes.c: Added SLang_push_function to complement
   SLang_pop_function.
3. src/slkeymap.c: SLkm_define_slkey implemented.  It was already
   declared in slang.h but never implemented until now.

Changes since 2.0.1
1. src/slang.h: Forgot to bump SLANG_VERSION to 20001.

Changes since 2.0.0
1. modules/png.sl: png_gray_to_rgb was missing an assignment after
   normalization.
2. slsh/lib/print.sl: Ignore SIGPIPE while in the pager.
3. src/slang.c: SLang_peek_at_stack1_n was broken.
4. src/slsmg.c: If the cursor is left outside the visible display area
   during SLsmg_refresh, then "clip" its position to the visible area.
5. src/slarray.c: Typo (= vs ==) was corrected in the array_eqs_method
   function. (Dino Sangoid)
6. src/slmath.c: Use IS_NAN macro instead of isnan (Dino Sangoid)
7. src/mkfiles/makefile.all: Added dll support for the mingw32 build
   (Marko Mahnic; marko mahnic at email, si)
8. src/slang.c: Removed a while loop that did nothing. (Dino Sangoid)
9. src/mkfiles/makefile.all, src/slconfig.h, src/slposdir.c: Support
   added for 16 bit systems using watcom C (Dino Sangoid)
10.doc/tm/*.tm: Some spelling errors corrected (Mike Noble)
11. src/slang.c, src/slnspace.c: There was a conflict between private
    and static namespaces that arose when _implicitly_ loading a file
    into a specified namespace.  Resolving this issue involved the
    complete separation of the private and static namespaces.
12. The _get_frame_info function now provides the name of the active
    namespace.
13. src/sldisply.c: Line drawing characters were not activated when
    xterm was started in locale mode.  Escape sequences were tweaked.
    (Alexander E. Patrakov, patrakov at ums, usu, ru)
14. slsh/lib/print.sl: If an element of an array of structs is NULL
    then print the element as NULL.
15. modules/varray.c: typo was preventing mmapping of a file from
    working properly.
16. slsh/lib/*.sl: changed "static" to "private" to protect the
    functions when loaded into a namespace.
17. autoconf/configure.ac: Add tests for atoll and strtoll.  Some
    versions of MacOS X do not have atoll.
18. modules/png.sl: Added png_get_colormap_names and changed
    examples/colormap.sl to use it.
19. src/slarrfun.c: Ignore _NaNs in min/max functions.
20. slsh/lib/sldbcore.sl: Added several aliases to the debugger:
    b(reak), c(ont), d(elete), h(elp), l(ist), n(ext), p(rint),
    pp(rint), q(uit), s(tep)

Changes since 2.0.0 pre-release 8
1. src/slang.c:  Under some conditions, no line number information was
   being reported for stack underflow errors.
2. lib/sldbcore.sl: Missing return value was causing a stack-underflow
   error. (Paul Boekholt)
3. src/slmisc.c,src/sltoken.c: In UTF-8 mode, an escaped sequence of
   the form "\xAB" is interpreted as a byte.  Previously, it was
   interpreted as a wide character.  To encode a wide character using
   an escape sequence, use braces ("\x{AB}").
4. src/slstd.c: The putenv function now throws an OSError exception
   upon failure.  Previously it threw a RunTimeError.
5. src/slerr.c: Added NamespaceError exception and changed some of the
   namespace specific function to throw this exception instead of a
   RunTimeError exception.
6. src/slang.h: SL_Domain_Error was missing from the file.
7. src/slerrno.c: If errno_string is called without an errno argument, the
   current value of _pSLerrno_errno will be used.
9. src/sltime.c: The "time" functions were changed from using an
   unsigned long to a long to match time_t.
10.src/slvideo.c: Corrected a typo in the non-Unix/non-VMS specific
   SLtt_utf8_enable function.

Changes since 2.0.0 pre-release 7
1. slsh/lib/structfuns.sl was missing from the distribution.
2. src/sldisply.c: SLtt_Blink_Mode set to have a default of 0 instead
   of 1.
3. slsh/slsh.c: Add -t option, which causes slsh_main (if defined) to
   not be executed.
4. src/sltoken.c:SLang_load_object: Do not reset the line_num field.
   This gives the line numbers in slsh interactive mode some meaning.
5. src/slsh/lib/slshrl.sl: Usage message for "exit"
6. src/slvideo.c: SLtt_utf8_enable function added
7. src/slexcept.c: If tracebacks are turned off, make sure that the
   line number field in exception objects is meaningful.
8. src/slang.c: SLang_peek_at_stack1_n was not working.  (Mike Noble
   mnoble at space, mit, edu).
9. src/slang.c: Small optimization tweak when dealing with a single
   array index.
10. src/slposio.c: Jorge Gonzalez, jgonzalez at atsautomation, com
    found and fixed a leak in the "read" function.
11. modules/png-module.c: New module to read/write png files.  It
    includes about 20 colormaps.  See examples/colormap.sl.
12. src/slclass.c: SLang_get_int_type returns the SLtype for the
    integer with the specified number of bits.
13. src/slarray.c: array_shape intrinsic function added as an
    alternative to array_info for getting the dimensionality of an
    array.
14. src/slospath.c: new intrinsic: path_basename_sans_extname
15. src/, slsh/: A number of win32 tweaks to support dynamic linking under
    windows. (Dino Sangoid; sangoid at lloydadriatico, it).
16. src/slstruct.c: Check for duplicate fields in a struct. (Doug
    Burke; burke at cfa, harvard, edu).
17. src/slarrfun.c: New matlab-like functions "any" and "all". (Doug
    Burke; burke at cfa, harvard, edu).
18. src/slang.c: Calling SLang_restart will also clear the slang error
    state.  There is no need to call SLang_set_error(0) after calling
    SLang_restart.
19. src/sltoken.c: Allow the evaluation of '#if (expr)' when created a
    pre-parsed file (.slc).
20. src/slang.c: If a function defined in the currently loading
    file is to also be autoloaded into another namespace, and that
    namespace is not current one, then make sure an anonymous
    namespace is being used.
21. src/slang.c, slboseos.c: Experimental support for a debugger.  New
    functions: 
       _set_frame_variable
       _get_frame_variable
       _get_frame_depth
       _get_frame_info
       _use_frame_namespace
22. slsh/lib/sdb*.sl: An experimental source code debugger based upon
    a Dino Sangoid's jed debugger.
23. src/slang.c: The "_pSL" prefix was dropped from a few file-local
    variables.  Also calls to _pSLclass_push_* were changed to calls to
    file-local specific versions of the functions.
24. src/slsh/mkfiles/: A couple of win32 icons for slsh were provided
    by Marko Mahnic (marko. mahnic at email, si)
25. src/slarray.c: If typeof(t)==DataType_Type, then put back the old
    behavior of array creation via t[N].
26. doc/tm/slang.tm: The slang manual has been updated for version 2,
    with numerous typos corrected.
27. slsh/scripts/sldb: New script that invokes the debugger.
28. src/slstruct.c: Added _is_struct_type.  This works like
    is_struct_type excepted if the object is an array, it returns
    information about the array elements.
29. slsh/lib/print.sl: The "print" defined by this file may be used to
    print arrays, structures, lists, etc.  It is also used by sldb's
    pprint command.


Changes since 2.0.0 pre-release 6
1. The _traceback variable was being ignored.  As a result, error
   messages were more verbose than requested.
2. I fixed the negative indexing issues and made such indexing much
   more consistent.  Before it was possible to index the first through
   last elements of an array using the index [0:-1].  However, there
   were too many inconsistencies associated with this feature.
   Negative indices are still supported but in a much more consistent
   fashion.  See UPGRADE.txt for more details.

Changes since 2.0.0 pre-release 5

0. src/slang.h+others: I created a new typedef in slang.h representing
   array indices (SLindex_Type).  This is used in the SLang_Array_Type
   structure.  Previously the affected fields were ints.  For backward
   compatibility, SLindex_Type is defined as an int.  This change was
   made with an eye to the future when 64 bit platforms become more
   common with physical memory such that one wants to index arrays
   with more than MAX_INT elements per dimensions (the current
   limit).
1. src/slarith.c: missing comma in a code block specific to 64 bit systems
   prevented compilation.
2. src/: OS/2 specific patches.
3. src/mkfiles/makefile.all: Added some ranlib commands for the mingw32,
   cygwin, and EMX compilers.
4. */mkfiles/makefile.all:  Add TOOL_PREFIX variable to support 
   cross-compilation.
5. slsh/slsh.c: win32 specific changes to get path to slsh.rc via
   the GetModuleFileName function (DINO SANGOI (SANGOID at lloydadriatico, it)).
6. slsh/mkfiles/makefile.all: Corrected the values of the SLANGINC and
   SLANGLIB variables.
7. src/slstd.c: atoll intrinsic was not getting defined. (Doug Burke
   (dburke at head-cfa, cfa, harvard, edu)).
8. src/test/longlong.sl: Add test for atoll (Doug Burke)
9. src/slerr.c: SLang_set_error: Allow an error to be cleared but not
   changed to another value in the presence of an error.
10. src/slarray.c: Allow a 1-d integer array to always address a
    multidimensional array.  Not just "sometimes".
11. slsh/lib/arrayfuns.sl: local variable a was multiply defined in
    reverse function.
12. src/slpack.c: Add support for long long and 64 bit types.  Also
    'z' specifier added as an alternative to 's'.
13. src/slstdio.c: Previously, fread(&v,Char_Type,n,fp) would 
    assign a BString_Type object to v if n>1 or Char_Type if n==1.
    Now, for consistency it returns Char_Type[n] for n > 1.  To get
    the value as a binary string, use fread_bytes.  This change is not
    backwards compatible and may break code that relies upon the old
    behavior.  See UPGRADE.txt for additional information.
14. src/slrline.c: A silly typo prevented multiple instances of
    readline objects.
15. slsh/: New intrinsic: slsh_readline.  This allows a script to get
    input from the user using the readline interface.
16. slsh/scripts/svnsh: A simple shell for interacting with an SVN
    repository.
17. src/slang.h: The SLANG_MODULE macro was incorrectly defined when
    compiled with C++.
18. src/slkeymap.c: A small memory leak was found by Gilles Mazoyer
    pgid at free, fr.
19. src/slarith.c,...: Some problems were found on 64bit big-endian
    machines.  Correcting this involved adding new functions to the
    interface long and short intrinsic constants.
20. src/slang.c: Inside a finally block, loops were not working if the
    exception handler issued a break or return statement.
21. src/slrline.c: On a 64bit big-endian system a SEGV would result
    when inserting text.
22. configure: CFLAGS added to the ELF_CFLAGS variable.  LDFLAGS added
    to the ELF_LINK variable.
23. src/slposdir.c: hardlink intrinsic added.
24. src/slexcept.c: "function" field added to the exception object.
25. src/slang.c: The way line number information is stored has been
    changed.  Now it is nolonger necessary to get line number
    information by setting the _debug_info variable.  In the process I
    tried to make the error messages somewhat more useful.
26. src/slang.h: SLvsnprintf and SLsnprintf functions made public
    Previously these were _pSLvsnprinf and _pSLsnprintf. (Dino Sangoid).
27. src/slang.c, _slang.h: Bytecodes were made enums instead of
    preprocessor symbols.
28. src/slang.h: External symbols have been prefixed with SL_EXTERN to
    facilitate the construction of a slang DLL on windows.  When
    compiling against the slang DLL, be sure to define SLANG_DLL.
    (Dino Sangoid).
29. src/sllist.c: Added foreach method to lists.
30. src/slsmg.c: Experimental feature: If rendering a character string
    that contains an character sequence of the form 'ESC [ x m', or
    'ESC [ x ]', where x represents a decimal integer, then the
    current color will be switched to the value of x.  If x is omitted
    (ESC[m) then the color will be set to the color active at the time
    of the function call.
    
       SLsmg_set_color (1);
       SLsmg_write_string ("This is a \033[123mnew\033[m feature");
    
    is equivalent to:

       SLsmg_set_color (1);
       SLsmg_write_string ("This is a ");
       SLsmg_set_color (123);
       SLsmg_write_string ("new");
       SLsmg_set_color (1);
       SLsmg_write_string (" feature");
    
    By default, this feature is turned off but may be turned on via 
    
        SLsmg_embedded_escape_mode (1);

    Although this special color-changing-byte-sequence looks like an
    ANSI escape sequence, the semantics are very different.
31. doc/tm/rtl/type.tm: The "string" function was documented as
    returning an integer.  (Doug Burke)

Changes since 2.0.0 pre-release 4
0. src/*: For POSIX compliance, all _SL* symbols were changed to
   _pSL*.  Change suggested by Alastair McKinstry.  If you experience
   a linker error such as "undefined symbol: _SLChg_UCase_Lut" after
   upgrading, then you will have to recompile your application.
1. src/slstring.c: Bug fix.  For some strings, a substring would
   produce the same hash as the full string.  As a result, the
   substring was not being properly generated.
2. src/slerr.c: For applications not using the interpreter,
   _pSLerr_init was not getting called.  As a result, the error-codes
   were not getting initialized.
3. src/slsmg.c: Bug fix affecting SLsmg_Newline_Behavior (Thomas
   Dickey).
4. src/doc/tm/rtl/strops.tm: typo caught by Doug Burke.
5. src/slstd.c: added atoi, atol, atoll as simple wrappers around
   corrsponding standard library functions--- same caveats apply.
6. src/slstd.c: New intrinsics: add_doc_file, get_doc_files,
   set_doc_files.  These functions facilitate the addition of
   documentation via a standard mechanism across all apps using the
   interpreter.
7. slsh: Interactive support with readline-editing added to slsh.  By
   default, the slang library readline functions are used.  If you
   want GNU readline, then run configure with the appropriate option.
   (This feature is due to Mike Noble, mnoble at space, mit, edu).
8. slsh: A man page for slsh (Rafael Laboissiere, rafael at debian, org).
9. src/slwclut.c: No provision was allowed for backslashes in ranges
   that also permitted character classes.
10. slsh/mkfiles/makefile.all: New file for non-unix systems. 
    (DINO SANGOI (SANGOID at lloydadriatico, it)).

Changes since 2.0.0 pre-release 3
1. New intrinsics: array_swap, array_reverse
2. src/slrline.c:SLrline_open: If the display width argument is 0, set
   it to 80.
3. sldisply.c: Initialize SLtt_Screen_Cols/Rows to (80,24) instead of
   (0,0).
4. src/slparse.c: Expressions such as &s.foo and &s[0] are flagged as
   unsupported at parse time.
5. src/slimport.c: A module may now be imported into more than one
   namespace.  See modules/README if you are a module writer.
6. slsh/Makefile.in, modules/Makefile.in: Made changes so that
   nothing gets compiled during the install step.
7. src/slimport.c: If "import" is called without a namespace argument,
   the current namespace will be used.  If the current namespace is
   anonymous, the global namespace will be used.
8. slsh/lib/require.sl:  The provide/require functions have been
   changed to take a namespace argument.
9. doc/tm/slang.tm: Added section on operator overloading for
   user-defined types.
10. doc/tm/tools/fixtxt: a jed-script to repair the text files
    generated by the linuxdoc sgml2txt program.
11. doc/tm/slang.tm: Corrected some typos spotted by Doug Burke.
12. src/mkfiles/makefile.all: DOS/Windows: The response file was not
    being properly generated (SANGOI DINO (SANGOID at lloydadriatico, it)
13. src/slang.c: The autoload function may be used to load a file into
    a namespace. (Based upon an idea from Jörg Sommer (joerg at alea,
    gnuu, de)
14. src/slstring.c: New hash function (from Bob Jenkins-- see 
    See http://burtleburtle.net/bob/hash/evahash.html)
15. src/slassoc.c: rewritten to use double hashing.


Changes since 2.0.0 pre-release 2
1. autoconf/aclocal.m4: "if [...]" replaced by "if test ..." (Lloyd
   Zusman)
2. src/slsearch.c: BM searches for a string with the same length as
   the string to be searched was failing.
3. slsh/scripts/jpegsize: New demo script that finds the dimensions of
   jpeg-encoded images.
4. src/slstd.c: Added _slang_install_prefix intrinsic variable.
5. src/slboseos.c: New file.  This file allows to define callback
   functions that will be called at the beginning (BOS) and end (EOS) of 
   every statement executed by the interpreter.
6. slsh/lib/stkcheck,sl: The code in this file makes use of the new
   BOS/EOS hooks to display lines in a source file that leave
   something on the slang stack.
7. examples/profile.sl: This file defines a few functions that take
   advantage of the BOS/EOS hooks to profile slang code.
8. src/slarrfun.inc: sum and cumsum tweaked to use a "compensated
   summation" technique to reduce the effect of roundoff and
   truncation errors.
9. src/slmisc.c: SLatoi("h") was producing 0, and not an exception.
10. src/slmath.c: On VMS, slang is compiled with IEEE support (Jouk
    Jansen).
11. src/slassoc.c: Rewrote the implementation to use a double hashing
    scheme.

Changes since 2.0.0 pre-release 1
1. slsh/lib/require.sl: Protect the Features variable against multiple
   loading.
2. src/*.c: VMS-specific patches from Jacob (=Jouk) Jansen.
3. src/slsearch.c: non-UTF-8 case-insensitive searches were not working.
4. src/SLwchar*.c: SLwchar_xxxx functions will use the current locale
   if UTF-8 has not been enabled for the interpreter.
5. src/sldisply.c: The display of double-wide unicode
   characters was not working properly under some conditions.
6. src/slsmg.c: If a double wide character is being displayed, then if
   a character is written to either of the cells occupied by the
   double wide character, then the opposing cell will be overwritten
   with a space.
7. src/sltoken.c: Characters specified as 'x' where 0 !=(x&0x80) were
   not being properly parsed.
8. src/aclocal.m4: --without-foo was not working.
9. src/slstrops.sl: Fixed an access error in the "string_match"
   function.

Changes since 2.0.0 pre-release 0
1. src/slpath.c: slpath_dirname on VMS was failing to include the
   closing "]" in its return value.
2. src/slprep.c: A comment in a slang "#ifdef" directive would cause
   an infinite loop.
3. src/slarray.c: An integer array such as [a:b:c] where a>b and c>b was being
   improperly computed.
4. src/slparse.c: Function calls with missing arguments was not being
   properly handled, e.g., func(,);
5. src/slang.h, src/slclass.h: SLclass_set_foreach_functions added.
6. src/slcurses.[ch]: changes added to support UTF-8 (Adrian Colley)
7. src/Makefile.in: $(prefix)/doc changed to $(prefix)/share/doc
   (Adrian Colley)
8. src/sldisply.c: Missing "break" added to tt_sprintf (Andrew V.
   Samoilov).
9. src/slang.c: SLang_peek_at_stack_n and SLang_peek_at_stack1_n
   functions added to peek deeper into the stack (Mike Noble)
10. src/slang.c: The actual name of the local variable is used in the
    traceback messages.
11. src/slsig.c: Support for the signals added to the
    interpreter.  The new intrinsics include: signal, sigsuspend,
    sigprocmask, alarm.
12. src/slcommon.c, slang.h: When system calls are interrupted, a set
    of "interrupt" hooks may be called.  The return values of the
    hooks determine whether or not the system call is restarted.
13. src/slang.c: If a string has a $ suffix, then
    variable name expansion will take place on the string, e.g., "$CC"$.
14. src/sldisply.c: misc patches (optimization and buffer
    overflow) (Andrew V. Samoilov)
15. src/slprep.c: #<whatever> was not working (Paul Boekholt).
16. src/sldisply.c: Applied a patch from Andriy I Pylypenko dealing
    with tgetstr on termcap-based systems.
17. src/slcurses.c: combining character support added to curses
    emulation (Adrian Colley)
18. src/slsmg.c: New function SLsmg_strwidth returns the displayable
    width of a character string assuming it will be displayed at the
    current position.
19. src/slstrops.c: string_match and string_match_nth work in terms of
    byte-offsets, not character offsets.  New intrinsics: strbytesub
    and substrbytes that substitute a byte and return a byte sequence,
    resp.
20. src/slarray.c: If A is a string, the A[n] returns a UChar_Type.
    Indexing a string using array notation uses byte-semantics.
21. src/slang.h: Tracing messages were being queued instead of
    processed right away.
22. src/slcommon.c: SLutf8_enable will use nl_langinfo if available.
23. src/slstdio.c: new intrinsic: fputslines
24. src/slerr.c: Explicit CRs (\r) removed from error and message
    handling routines.
25. modules/: smg-module.c renamed to slsmg-module.c, with similar
    name changes to the module symbols.  Also, for each xxx-module.c, a
    new xxx.sl was added to be installed in the slsh install-dir so
    that slsh's "require" will pick up the specified module.

Changes since 1.4.9
0. There have been many changes for the version 2 release.  See NEWS
   and UPGRADE.txt for some of the changes.  The ones listed here were
   to appear in 1.4.10, if released.  Version 2 contains these changes
   and many more.
1. src/slang.c: Test for local variable stack overflow was using >
   instead of >=.
2. src/slarray.c: Fixed a bug that prevented 7 dim arrays from being
   indexed.  Similar problem to #1 above: > vs >=.
3. src/slassoc.c: The following caused a segv:
       X = Assoc_Type[Int_Type]; X["foo"] = [1:10];
   Now a type-mismatch error will get generated.
4. src/slerr.c,sltermin.c: Off by 1 calculations of buffer-sizes fixed
   by Andrew V. Samoilov (andrew at email, zp, ua).
5. src/slkeypad.c: More escape sequences courtesy of Denis Zaitsev
   (zzz at cd-club.ru)
6. src/slerr.c: SLang_get/set_error functions have been added to the
   API to get and set the value of SLang_Error, resp.  The variable
   SLang_Error will be removed from slang 2.  Applications should
   start using these functions to ease migration to the next version.
7. src/slstruct.c: Added SLang_push/pop/free_struct functions to
   public API.  The objects themselves are still opaque.
8. src/slparse.c: allow the semi-colon to be used as a field separator
   in a structure declaration.
9. src/slpath.c: path_sans_extname was failing when a dot was in a
   directory part of the name.
10. slsh/slsh.c: The names of environment variables defining the location of
   the global slsh.rc and the slsh library files may be specified in
   slsh/Makefile.
11. src/sltoken.c: Local buffer overflow when the size of an
    identifier exceeds 256 characters was found and corrected.
12. src/slarray.c: Leak fixed: Under some circumstances, a memory leak was
    generated when using user-defined "typedefd" objects in an array,
    e.g.,
        typedef struct {a} Foo_Type;
	()=[Struct_Type[1],@Foo_Type];
13. src/slarray.c: Indexing a multi-dimensional array using a
    mult-dimensional array was broken. Now A[I] returns an array with
    the same dimensionality as I, regardless of the dimensionality of A.
14. New intrinsics:
       __is_callable     (Mike Noble mnoble at space, mit, edu)
       __is_numeric      (Mike Noble mnoble at space, mit, edu)
       __datatype        (John Houck houck at space, mit, edu)
       mktime
       symlink

Changes since 1.4.8
1. src/slarray.c: superfluous call to SLclass_add_math_op removed
   (Michael Noble <mnoble at space.mit.edu>)
2. src/slang.c: foreach (NULL) using("next"){} foo (); caused _NARGS=1
   in foo.
3. src/slarrfunc.c: Fix to prevent sum(NULL) from causing a core-dump.
4. src/slimport.c: import (module, "") made equivalent to
   import(module,"Global");  This way, import(module, current_namespace())
   will work when the current namespace is anonymous.
5. src/slospath.c: Several users have requested that I add the ability
   to define a load path and use that path when loading interpreter
   files.  To this end, several new functions were added to the API:
   
       char *SLpath_get_load_path (void);
       int SLpath_set_load_path (char *path);
         /* Get and Set the path to be searched for files */
       int SLpath_get_path_delimiter (void);
       SLpath_set_path_delimiter (int delimiter);
         /* Get and set the character delimiter for search paths */
       int SLang_load_file_verbose (int verbose);
         /* if non-zero, display file loading messages */
   
   New intrinsics include:

       set_slang_load_path
       get_slang_load_path
       path_get_delimiter
       
   These functions, nor the intrinsics have an effect on applications
   that use SLang_load_file_hook or SLns_load_file_hook for loading
   files.  The change should be transparant to applications that use
   the stock load file mechanism.  The main difference is that if one
   attempts to load a file with no extension, e.g., "foo", but the
   file does not exist, then the interpreter will try to load the more
   recent of "foo.sl" and "foo.slc".
   
   See src/slsh.c for how the functions may be used.

6. slsh/slsh.c: Updated to use the new search path code outlined
   above.  Also, slsh is distributed with a collection of general
   purpose slang functions, including jed's provide/require functions.
   See slsh/README for more information.
7. doc/tm/cslang.tm: Modified the section describing the implemetation
   of intrinsic functions in an effort to clarify the discussion.
8. src/slang.c: tiny memory leak resulting from peephole optimzations
   added earlier found and fixed.
9. src/slarrmisc.c: new intrinsic: cumsum computes the cumulative sum
   of an array via the new SLarray_map_array function.
10. src/modules: perl compatible regular expression (pcre) module added.

Changes since 1.4.7
1. src/sldisply.c: make sure SLtt_erase_line leaves the cursor at the
   beginning of a line in all cases.  Previously, this happened only
   for terminals able to delete to the end of line _and_, when
   writing to the last line, the ability to insert a character.
2. doc/tm/cslang.tm: In the discussion of the MAKE_CSTRUCT_FIELD
   macro, SLANG_STRING_TYPE was used instead of SLANG_INT_TYPE
   (mnoble at space.mit.edu).  Similarly, in the discussion of intrinsic
   structures, My_Window was used instead of My_Win
   dburke at head-cfa.cfa.harvard.edu.
3. src/slang.c: peephole optimizations of 1.4.7 were conflicting with __tmp
   optimizations.  This was causing something as simple as
   
       define f() 
       { 
          variable a = [1.0:10.0:1]; 
	  variable b = a * 0.0;
	  return a;
       }
   
    to fail.
4. src/slarray.c Allow ranges to index higher dimensional array.
5. slsh/slsh.c: Updated to allow a user specified search path.  See
   slsh/README for more info.

Changes since 1.4.6
1. src/slclass.c: Change "-??-" to "- ?? -" to avoid its
   interpretation as a trigraph. Miquel Garriga <miquel at icmab.es>
2. src/mkfiles/makefile.all: If compiling with mingw32, use "cp"
   instead of "copy". Miquel Garriga <miquel at icmab.es>
3. src/sllimits.h: Increased the size of the local variable and
   recursion stacks on 32 bit systems.
4. src/slarrfun.c: "sum", "min", and "max" intrinsic functions added.
   Since these may conflict with application defined function, they
   have been placed in their own module.  To get them, use
   SLang_init_array_extra --- SLang_init_all will not pick up this
   module.  Version 2 of the library will add these functions to the
   main array function module.
5. src/sltermin.c: Work around a bug in the solaris 7+8 tset program
   which improperly sets the TERMCAP environment variable
   (Paananen Mikko <mikkopa at cs.tut.fi>).
6. src/slprep.c: Added support for "#stop" and a few other useful
   or convenient features.  See comments at the top of slprep.c for
   more details. (Mark Olesen <molesen at zeunastaerker.de>).
7. src/<misc>.c: "const" qualifier added to several places to put
   constant variables in rdata/text segment to be shared between
   other processes. ("Andrew V. Samoilov" <samoilov at usb.zp.ua>)
8. src/sldisply.c: If colors were defined using the "Sf" capability
   instead of the "AF" capability, then assume those are specified in
   BGR format instead of RGB. (Pavel Roskin <proski at gnu.org>)
9. slsh/slsh.c: "status" was not declared if compiled with
   SLSH_LIB_DIR defined. (mnoble at space.mit.edu)
10. slsh/Makefile.g32: new file to allow slsh to be compiled with
    mingw32.
11. src/sldisply.c,sltermin.c: if running as setuid/setgid, then limit
    access to the environment for such a process. <solar at openwall.com>.
12. src/slstd.c: New intrinsic function _get_namespaces may be used to
    get a list of currently defined namespaces.
13. src/slstruct.c: better support for pushing and popping structures
    from C via the SLang_push/pop_cstruct.  See doc/text/cslang.txt
    for details.
14. slsh/Makefile.in: install target added
15. src/slang.c: additional peep-hole optimizations added
16. src/*.c: fixes it enable the library to be compiled without floating
    support support.

Changes since 1.4.5
1. doc/tm/rtl/struct.tm: Typos in documentation for set_struct_fields
   corrected by Douglas Burke <dburke at head-cfa.harvard.edu>.
2. src/sldisply.c: VMS specific problem: SLang_TT_Write_FD was not
   getting initialized (Hartmut Becker <Hartmut.Becker at compaq.com>).
3. src/slarith.c: On a 64 bit system, it was possible that Int_Type
   objects were not getting properly converted to Double_Type.
4. src/sltoken.c: A unitialized memory reference fixed in the
   error handling of an empty character declaration ('').
5. src/slstd.c: call to _SLinit_slcomplex moved to slmath.c.  This
   means that one does not get complex number support unless math
   support is also enabled.  (suggested by Michael Noble
   <mnoble at head-cfa.harvard.edu>)
6. src/slclass.c: Make sure that when registering a class using
   SLANG_VOID_TYPE, the reserved class ids are not used.
7. src/slmisc.c, src/sltoken.c: moved SLatoi and friends from sltoken
   to slmisc.c.  This avoids linking in the interpreter when it is not
   needed.
8. doc/tm/rtl/array.tm: Documentation for the "where" function
   corrected by <G.Milde at physik.tu-dresden.de>.
9. src/slkeypad.c: support added for F11 and F12 keys
10. src/slimport.c: Better handling of dlopen errors as suggested by
    Michael Noble <mnoble at head-cfa.harvard.edu.
11. src/slstruct.c: make sure field names have legal names.
12. src/slistruct.c: SLns_add_istruct_table added.
13. src/sltoken.c: New name-space specific functions added:
      SLns_load_file, SLns_load_string
    These may be used to load a file or a string into a specified
    namespace.  Simarily, the "eval" and "evalfile" functions may now
    be given a second argument to specify a namespace.
14. src/slstd.c: __eqs function added to test for "sameness" of
    its arguments, __class_type returns information about how an
    object is classified, __class_id to return its class id.  See
    examples/saveobj.sl for an example of the use of these functions.
15. src/slarray.c: a 2-d array can nolonger be specified in-line as,
    e.g., [[1,2],[3,4]].  This now produces a 1-d array: [1,2,3,4].
16. src/slregexp.c: fix for case-insentive matches involving e.g.,
    a\{1,3\} type regexps (Thomas Schultz <tststs at gmx.de>)
17. src/slarray.c: Allow setting elements of pointer type arrays to
    NULL, e.g., a[10] = NULL.
18. src/slsignal.c: If CYGWIN, then assume posix signal handling works.
19. src/slang.c: Do not allow an intrinsic function, variable, etc
    table to be added twice.
20. src/slarray.c: Added _isnull intrinsic for checking for NULL values of
    array elements.  This is useful since something like
    "where(a==NULL)" does not check the individual elements, whereas 
    "where(_isnull(a))" does.
21. src/sldisply.c: typo involving the initialization of Del_Eol_Str 
    for terminals that do not have such capability.
    (Pavel Roskin <proski at gnu.org>)

Changes since 1.4.4
1. Added QNX specific patches and fixed some typos that prevented it
   from compiling when _SLANG_OPTIMIZE_FOR_SPEED is 0. (Tijs Michels
   <tijs at vimec.nl>).
2. Make sure '#ifeval expr' evaluates up to the end of a line and no
   further.
3. src/sldisply.c: Do not look for pad info in the graphic charset
   pairs string.  Also, when comparing space characters, be sure to
   take into account ACS.  (Marek Paliwoda <paliwoda at inetia.pl>)
4. Trivial code cleanups to avoid BCC 5.x warnings.
5. src/mkfiles/makefile.all: BCC-specific tweaks (John Skilleter
   <John.Skilleter at pace.co.uk>)
6. SLang_push/pop_datatype made public
7. src/slutty.c: if tty is not initialized and an attempt is made to
   read from the tty, set errno to EBADF.
8. src/slkeypad.c: New function SLkp_set_getkey_function.  This may be
   used to specify a different function to read keys.
9. src/slcurses.c: If an invalid keysequence is entered, simply return the
   characters of the sequence on successive getkey calls.
10. src/slarray.c: Inline arrays of the form [1f, 0] were not working.
11. src/sldisply.c: Make sure SLtt_get_screen size gets called by
    SLtt_initialize.
12. doc/tm/rtl/struct.tm: typeof in example for get_struct_field_names
    corrected by Chris Baluta.
13. modules/varray.c: example showing how a memory mapped array may be
    created.  It also illustrates the free_fun callback for arrays.
14. examples/life.sl: a S-Lang implementation of Conway's life.
15. src/slclass.c: SLclass_dup_object function added.  Although
    push/pop can be used to achieve a duplicated object, this function
    makes it a little easier.
16. src/slang.h: Prototyes involving "unsigned char" to represent data
    types have been modified to use SLtype, which is typedefed to be
    an unsigned char.  V2 will use a different size for data types.
17. Misc tweaks to aclocal.m4, src/Makefile.in, etc to support MacOSX.
    I have not tested it on that system.
18. The library may now be compiled under CYGWIN using the same
    procedure as under Unix.
19. src/slkeypad.c: Some xterm-specific escape sequences added by
    Denis Zaitsev <zzz at cd-club.ru>. 

Changes since 1.4.3
1.  Fixed a bug that shows up on 64 bit BigEndian machines--- it
    affected no others.
2.  Fixed potential problem in pre-parsing binary strings.
3.  Bug a fixed affecting only pure termcap-based systems.  It has
    been around a while, I am surprised that it took so long to be
    discovered.

Changes since 1.4.2
1.  If init_NAME_module_ns does not exist in a module, then try to
    load init_NAME_module as long as the module is to be imported into
    the Global namespace.
2.  src/sldisply.c: allow more than 200 rows and 250 columns.  Who
    uses such windows?
3.  Allow Void_Type to be specified for the data-type in array_map if the
    function returns nothing.
4.  src/slarray.c: A statement such as [1:-1][[1:-1]] = [1:-1]; was
    causing a core dump.
5.  src/sldisply.c: (Unix/VMS) SLsmg/SLtt routines will write using the file
    descriptor SLang_TT_Write_FD, which, by default, is initialized to 
    fileno(stdout).
6.  src/slposio.c: New C API functions: 
       SLfile_get_fd returns the file descriptor associated with the 
         SLFile object.
       SLfile_dup_fd: duplicate an SLFile object
7.  src/slposio.c: New intrinsics: dup_fd (dup a file descriptor)
8.  SLerrno.c: C API Function: SLerrno_set_errno.
9.  SLerrno.c: More errno values added.
10. Raising complex types to powers supported.
11. slang.c: current_namespace was returning "global" instead of
    "Global" for the global namespace.
12. slang.c: `use_namespace("X");define f();' was not placing `f' into
    `X'.
13. path_is_absolute fixed to return integer
14. src/slarray.c: generate an error when an empty array is passed to
    array_map.
15. src/slarray.c: a=3; a[*] should return an array.
16. Make sure setlocale(LC_NUMERIC,"C") gets called.
17. slvideo.c: SLtt_set_cursor_visibility implemented for win32.
18. slvideo.c: SLtt_get_screen_size corrected for win32 by Zusha P.
19. configure: modified to not automatically assume that -ldl is
    required for dlopen. In addition, molesen at zeunastaerker.de sent
    patches for building dynamically linked library under irix.
20. slsh/Makefile: generated by configure.
21. modules/Makefile: generated by configure
22. src/slimport.c: If no module path has been set, fall back on
    $(prefix)/lib/slang/modules
23. src/Makefile.in: DESTDIR support added by Brad <brad at comstyle.com>.
24. src/Makefile.in: documentation is installed in $(prefix)/doc/slang
    and no longer in $(prefix)/doc/slang/$(slang_version)
25. sleep intrinsic can take a floating point number to sleep
    fractional seconds.
26. src/slang.c: fix SLang_run_hooks to accept a namespace qualifier.
27. New modules added to the module directory: fcntl, select, termios.

Changes since 1.4.1
1.  slang.c: Under certain conditions, the continue statement was not
    properly handled in do..while statements.  src/test/loops.sl added
    for testing.
2.  slparse.c: avoid potential (rare?) infinite loop when slang error occurs
    (Stanis³a Bartkowski <sb at protest.com.pl>).
3.  slsmg.c: When SLsmg_init_smg is called, mark the display as trashed.
4.  It is now possible to add intrinsics to their own namespace via
    new SLns_add* functions.  Moreover, the import function now takes
    an optional additional argument that specifies a namespace.
5.  New namespace intrinsics: use_namespace, current_namespace
6.  Changed inner-product algorithm to minimize the number of cache
    misses.
7.  sldisply.c: Kanji specific patch from Jim Chen
    <jimc at ns.turbolinux.com.cn>.
8.  sldisply.c: Assume that Eterm and rxvt are xterm-like (Michael
    Jennings <mej at valinux.com>).
9.  sldostty.c: mouse support added by Gisle Vanem <giva at bgnett.no>.
10. slsearch.c: avoid infinite loop if search string has no length.    
11. SCO elf support added by Mike Hopkirk <hops at sco.com>.
12. slregexp.c: regexp \d+ was not working properly
13. keyhash.c: typos involving USER_BLOCK keywords corrected.
    (the use of USER_BLOCKs is discouraged).
14. New intrinsic variable: _slang_doc_dir.  This specifies the
    installation location of the doc files.
15. Make sure it can compile with  SLTT_HAS_NON_BCE_SUPPORT set to 0.

Changes since 1.4.0
1.  slw32tty.c: `v' key was not being handled on win32 systems.  Also,
    Shift-TAB will now generate ^@-TAB.
2.  New intrinsic function: strreplace.  This is more flexible than
    str_replace.
3.  VMSMAKE.COM: slstring added to list of files to get compiled.
4.  slsh/Makefile, modules/Makefile: added patch from Jim Knoble
    <jmknoble at pobox.com> to create elf versions (make ELF=elf).
5.  AIX IBMC patches from Andy Igoshin <ai at vsu.ru>.
6.  autoconf/config.sub: tweaked to properly handle recent alpha
    systems.
7.  If compiling on an alpha, add -mieee compiler flags.
8.  SLang_roll_stack and SLang_reverse_stack functions made public.
9.  SLang_free_function added.  If you call SLang_pop_function, then when
    finished, call SLang_free_function.  This does nothing in 1.X but
    may do something in 2.x.
10. src/slrline.c: Keybindings for ESC O A, etc added.
11. src/slsmg.c: SLsmg_write_nstring: avoid many loops if an extremely
    large value is passed (> 0x7FFFFFFF).
12. src/slregexp.c made thread safe
13. src/slsmg.c: Cursor was not always properly positioned when
    after SLsmg_touch_lines called.
14. If terminal does not have erase to eol capability, then use spaces.
15. doc/tm/strops.sl: doc for strcat updated to reflect its ability to
    concatenate N strings.
16. Documentation updated to indicate that floating point range arrays
    are open intervals such that [a:b] does not include b.  slarray.c
    was modified to enforce this specification.  Previously, whether
    or not b was included in the interval was indeterminate.
17. src/slsmg.c: bug involving SLsmg_set_screen_start fixed.
18. src/slparse.c: parser was failing to catch misplaced `}'.

Changes since 1.3.10
1.  If a floating point exception occurs and the OS allows the library
    to handle it without forcing a longjmp, then SL_FLOATING_EXCEPTION
    will get generated instead of SL_INTRINSIC_ERROR.  Note: Linux
    provides no way to handle floating point exceptions without
    forcing a longjmp.  In my opinion, this is a flaw.
2.  SLang_pop_double was returning the wrong value for short and
    character types.
3.  New intrinsic: is_struct_type(X) ==> non-zero is X is a struct.
4.  typecast operation from user defined type to Struct_Type added.
5.  slkeypad.c: DOS/Windows DELETE_KEY definition added (Doug Kaufman
    <dkaufman at rahul.net>)
6.  slposdir.c: Do not depend upon the existence of rmdir on VMS
    systems.
7.  slang.c: abs, sign, mul2, chs, sqr were not being treated as
    function calls.
8.  sldisply.c:SLtt_cls:  If the terminal is a color terminal but
    being used as a black and white terminal, then reset colors before
    clearing.
9.  path_sans_extname intrinsic added.
10. slimport.c: If module defines deinit_NAME, will be be called prior
    to unloading the module. (Ulrich Dessauer <des at gmx.de>)

Changes since 1.3.9
0.  typedef unsigned short SLsmg_Char_Type added to slang.h.
    Applications that access SLsmg functions read/write_raw and
    SLsmg_char_at should use SLsmg_Char_Type unstead of unsigned short
    because this will be changed to unsigned long in version 2.0.

1.  Documentation patches from Vlad Harchev <hvv at hippo.ru> added.
2.  slstring.c:  offsetof(SLstring,bytes) -->
    offsetof(SLstring,bytes[0]) to avoid compiler warning on some
    systems.
3.  slcmplex.c: an int was used where a double should have beed used.
4.  egcs g++ was optimizing slang.c:SLclass_push_ptr_obj away because
    it was declared as inline.  In my opinion, this is another g++ bug.
5. sscanf intrinsic added.  See docs.
6. SLmake_lut rewritten to correct incorrect handling of ranges with a
   hyphen at the end.
7. Small bug involving non-BCE terminals in SLsmg_set_color_in_region
   fixed.
8. Functions SLcomplex_asinh/acosh/atanh implemented.
9. install-elf will nolonger install .h files twice.
10. @Struct_Type may be used to create a struct.
12. X[i]++, X[i]-=Y, etc implemented.
13. Much of slw32tty.c rewritten to fix several bugs in the win32 tty
    support.  In addition, if SLgetkey_map_to_ansi(1) has been called,
    then function and arrow keys will produce escape sequences that
    allow one to distinguish alt, ctrl, and shift function keys.
14. OS/2 specific typo in slposdir.c corrected (Eddie Penninkhof
    <wizball at xs4all.nl>).
15. slang.c:add_slang_function: On the very rare occasion that this
    function failed, memory would get freed twice.

Changes since 1.3.8
1. Color was not enabled on VMS.
2. If MAKE_INTRINSIC was used to declare a function which takes
   arguments, then a typecast error would result when the function was
   called.  New programs should not use MAKE_INTRINSIC since it
   bypasses argument type-checking.
3. src/sl-feat.h: SLTT_XTERM_ALWAYS_BCE variable added to force the
   assumption of the bce (background-color-erase) capability of xterm.
   The default is 0, which means to accept the terminfo setting.
   To force it to 1 during run-time, set the COLORTERM_BCE environment
   variable.  This is useful when using, e.g., rxvt to login to a
   solaris system where the terminfo file will probably not indicate
   bce.
4. SLw32tty.c:SLang_init_tty: Open CONIN$ instead of using
   GetStdHandle.  This is necessary if stdin has been redirected.
5. SLposdir.c: Stat structure contains new field `st_opt_attrs' that
   may be used to contain system specific information that `struct
   stat' does not provide.  In particular, under win32, this field
   contains the file attributes, e.g., whether or not a file is
   hidden.
6. Appropriate typecasts added to avoid warnings on systems that do not 
   support `void *'.
7. Characters in the range 128-255 are allowed in identifiers.
8. Correction to the documentation for SLang_init_tty (Ricard Sierra
   <irebulle at nexo.es>).
9. SLANG_END_*_TABLE macros added to quiet silly egcs compiler warnings.
10. typo in sltime.c caused it not to compile under Ultrix.
11. Speed improvement of binary operations involving arrays,
    particularly when used in conjunction with the __tmp function.
12. traceback messages include the filename containing the function
13. File local intrinsic variable `_auto_declare' added.  If non-zero, 
    any undefined global variable will be given static scope.
14. __uninitialize intrinsic function added.
15. listdir was returning NULL on empty directories.  It has been
    changed to return String_Type[0].  It will return NULL upon error.
16. slang.h: if __unix is defined, then also define __unix__ (Albert
    Chin-A-Young <china at thewrittenword.com>).
17. foreach using extended to File_Type objects.  See documentation.
18. Tweak to the inner-product operator such that if A is a vector,
    and B is a 2-d matrix, then A will be regarded as a 2-d matrix
    with 1 column.

Changes since 1.3.7
0. configure script updated to autoconf 2.13.  If /usr/include/slang.h
   exists, then the default prefix will be set to /usr.
1. Compile error fixed if _SLANG_HAS_DEBUG_CODE is 0.
2. Bug fix involving typecast(Array_Type, Any_Type).
3. __IBMC__ patches from Eddie Penninkhof <wizball at xs4all.nl>.
4. If A = Assoc_Type[] (Any_Type array), then A[x] automatically
   dereferences the Any_Type object.
5. Bug fixed involving Assoc_Type optimization cache.
6. Tweaks to SLtt_smart_puts for improved performace.
7. array_map modifed such that the first array in its argument list
   controls the number of elements in the output array.  This is a
   backward compatible change and makes the function more flexible.
8. Additional tweaks to speedup array inary functions if
   _SLANG_OPTIMIZE_FOR_SPEED > 1.
9. Patch from Thomas Henlich <henlich at mmers1.mw.tu-dresden.de> fixing
   a problem with the `SLang_define_case' function, which allows
   customization of the upper/lower case tables.
10. strtrans and str_delete_chars intrinsic functions added.
11. tweaks to interpreter for some additional speed.

Changes since 1.3.6
1. Added a modified version of a patch from Martynas Kunigelis
   <martynas at diskena.dammit.lt> to allow writes to the lower left
   corner.
2. SIZEOF_LONG changed to 4 for VMS alpha systems (Jouk Jansen
   <joukj at hrem.stm.tudelft.nl>).
3. MSC patches from gustav at morpheus.demon.co.uk (Paul Moore).  He also
   contributed code for listdir with MSC.
4. SLsmg.c: Background color erase tweaks for terminals that lack this
   capability.
5. Fixed a NULL pointer dereference when doing Struct_Type[2][0].
6. Added slsh/scripts/ls and slsh/scripts/badlinks.  `ls' is designed
   for non-Unix systems and `badlinks' finds all symbolic links in
   specified directories that point to non-existent files.
7. SLang_Version_String and intrinsic variable _slang_version_string
   added.
8. stat_file modified under win32 such that a trailing `\' is stripped
   if present.
9. stat_is intrinsic modified to return a character instead of an
   integer.
10. The matrix-multiplication operator `#' now performs inner-products
    on arrays, e.g.,  if A and B arrays:
         A = A_i..jk
	 B = B_kl..m
    Then, (A#B)_i..jl..m = A_i..jk B_kl..m where k is summed over.
    This means that `#' is a matrix multiplication operator for 2-d
    arrays, and acts as a dot-product operator for 1-d arrays.
    In the process, it has been extended to complex numbers.

11. _reshape intrinsic function added.  Unlike `reshape', this
    function creates a new array and returns it.
12. Array indexing via characters works again, e.g., A['a'].
   
Changes since 1.2.2
0. New assignment operators: *= /= &= |=
   The addition of these operators meant that some of the internal
   byte-codes had to be modified.  This change should only cause
   problems with byte-compiled or preprocessed .sl files.  As far as I
   know, only the JED editors uses this feature.  So, after upgrading
   the library, and before running JED, do the equivalent of
   
        rm $JED_ROOT/lib/*.slc

   That is, delete the byte-compiled .slc files.

1. Now the language supports `!if ... else' statements.  
2. New intrinsics: 

       __is_initialized:  This may be used to see whether or
          not a variable is initialized, e.g, __is_initialized (&variable);
       __get_reference: Returns a reference to an object with a
          specified name.
       rmdir, rename, remove (slfile.c): these return 0 upon success, -1 upon
          failure and set errno
       getpid, getgid, getppid (slunix.c)
       _typeof: This is similar to `typeof' except in the case of
          arrays where it returns the data type of the array
       __pop_args, __push_args: see documentation
       fseek, ftell, and symbolic constants SEEK_END, SEEK_CUR, SEEK_SET
       sleep
       usage

3. `Conj' function added to get the complex conjugate
4. New array module that implementes additional array functions, e.g.,
   transpose, matrix multiplication, etc...  Use `SLang_init_array' to
   initialize.
5. An array such as [[1,2,3],[4,5,6]] is interpreted as a 2-row
   3-column array.
6. Amiga patches from Jörg Strohmayer <j_s at gmx.de>.
7. New table types:

       SLang_IConstant_Type
       SLang_DConstant_Type
       
   These are useful for defining symbolic constants.  See slmath.c and
   slfile.c for examples of their use.

8. A new pseudo-function: __tmp
   This `function' takes a single argument, a variable, and returns
   the value of the variable, and then undefines the variable.  For
   example,
   
        variable x = 3;
	variable y;
	y = __tmp(x);

   will result in `y' having a value of `3' and `x' will be undefined.
   The purpose of this pseudo-function is to free any memory
   associated with a variable if that variable is going to be
   re-assigned.  For example, consider:

        variable x = [1:10:0.1];
        x = 3*x^2 + 2;

    At the time of the re-assignment of `x' in the last statement, two
    arrays will exist.  However,

        x = 3*__tmp(x)^2 + 2;
    
    results in only one array at the time of the assignment, because
    the original array associated with `x' will have been deleted.  This
    function is a pseudo-function because a syntax error results if
    used like
    
        __tmp (sin(x));

9.  New low-level push/pop functions that are designed specifically
    for use in constructing the push/pop methods of application
    defined data types.  These functions have names of the form:
    
        SLclass_push_*_obj
        SLclass_pop_*_obj
	
    where * represents int, long, char, short, ptr, double, float.
    See sltypes.c to see how they are used by, e.g., SLANG_INT_TYPE.

10. New module import facility.  See modules subdirectory for
    examples.  To enable this, use

        SLang_init_module
	
    in you application.  Modules will be searched in the following order
    
        1.  Along the path specified by the `set_import_module_path'
	    function, or by the C functiion SLang_set_module_load_path.
	2.  Along the path given by the SLANG_MODULE_PATH environment 
	    variable.
	3.  Along a system dependent path, e.g., LD_LIBRARY_PATH
        4.  In the current directory.

    New interpreter intrinsics include:
    
        import (String_Type MODULE_NAME);
	set_import_module_path (String_Type PATH);
	String_Type get_import_module_path ();

11.  New integer and floating point types added to the language.  Now
     all basic C signed and unsigned integer types are supported:

       C bindings             S-Lang bindings
       ---------------------------------------
       SLANG_CHAR_TYPE        Char_Type
       SLANG_UCHAR_TYPE       UChar_Type
       SLANG_SHORT_TYPE       Short_Type
       SLANG_USHORT_TYPE      UShort_Type
       SLANG_INT_TYPE         Int_Type
       SLANG_UINT_TYPE        UInt_Type
       SLANG_LONG_TYPE        Long_Type
       SLANG_ULONG_TYPE       ULong_Type
       SLANG_FLOAT_TYPE       Float_Type
       SLANG_DOUBLE_TYPE      Double_Type
       
    For example, `Long_Type[10]' creates an array of 10 longs.

12. New intrinsic: set_struct_field.  See function reference for more
    info.

----- snapshot slang1.3_981030 made available -----

13. Type synonyms added: 

        Int16_Type, UInt16_Type   (16 bit (un)signed integer)
        Int32_Type, UInt32_Type   (32 bit (un)signed integer)
        Int64_Type, UInt64_Type   (64 bit (un)signed integer)
        Float32_Type              (32 bit float)
        Float64_Type              (64 bit float)

    Not all systems support 64 bit integers.  These synonyms are
    useful when one needs integers and floats of a definite size.

14. array_sort changed to use qsort.  The main reason for this is that
    the previous sorting method was derived from a numerical recipes
    merge sort.

15. New namespace manipulation functions available.  When a function
    or variable is declared as `static', it is placed in the private
    namespace associated with the object being parsed (a file).  By
    default, there is no way of getting at that function or variable
    from outside the the file.  However, the private namespace may be
    given a name via the `implements' function:
    
         implements ("A");

    Then the private variables and functions of the namespace A may be
    accessed via A->variable_name or A->function_name.  The default
    global namespace is called `Global'.  For example, the intrinsic
    function `message' is defined in the global namespace.  One may
    use either of the following forms to access it:
    
         message ("hello");
	 Global->message ("hello");

----- snapshot slang1.3_981104 made available -----

16. New intrinsics: 

        strtok  (See documentation)
	length  (Get the length of an object)

17. New data type added: Any_Type.  An array of such a type is capable
    of holding any object, e.g.,
    
         a = Any_Type [3];
	 a[0] = 1; a[1] = "string"; a[2] = (1 + 2i);
	 
    Dereferencing an Any_Type object returns the actual object.  That
    is, @a[1] produces "string".
    
18. Associative arrays added.  See documentation.
19. New `foreach' statement.  See the section on `foreach' in
    doc/text/slang.txt as well as the examples in examples/assoc.sl
    and src/calc.sl.
20. Oops.  sign function was broken.
21. array_sort modified to also accept &function_name.

----- snapshot slang1.3_981116 made available (1.3.4) -----

22. Before, it was necessary for the aplication to to call
    SLang_init_slassoc to enable associative array support.  This is
    nolonger necessary if associative array support is enabled in
    sl-feat.h.

23. Examples in the documentation modified to use foreach whenever a
    simplification occurred.

24. Max screen size for 32 bit systems inclreased to 256 rows.

25. `private' keyword added to prevent access to an object via the
    namespace.  This works exactly like `static' except that `static'
    objects may be accessed via the namespace.

26. structure access methods now available for application defined
    types (cl_sput, cl_sget).  Also, note that array access methods
    are also available.  See slassoc.c for examples.

27. If x is a string, then x[[a:b]] produces a string composed of the
    characters x[a], ... x[b].

29. New intrinsics: 

       listdir:  This returns the filenames in a specified
                 directory as an array of strings.

30. Source code for intrinsic functions reorganized in a more coherent
    fashion.  In particular, SLang_init_slfile and SLang_init_slunix
    are obsolete (though still available) and applications should call
    a combination of the new functions:
    
          SLang_init_stdio()   /* fgets, fopen, ... */
          SLang_init_posix_process () /* getpid, kill, ... */
          SLang_init_posix_dir () /* mkdir, stat, ... */

    Note that `unix_kill' has been replaced by `kill'.  So, if you use
    unix_kill in your application, change it to `kill'.

31. It is now safe to redefine an object while executing the object,
    e.g., this is now ok:

       define f(x) { eval ("define f(x) { return x; }"); }

32. Binary strings added.  This means that it is now possible to use
    strings with embedded null characters.  Too fully exploit this new
    feature, `fread' and `fwrite' functions were added to the stdio
    module.  In addition `pack', `unpack', `sizeof_pack',
    `pad_pack_format' were added for converting between binary strings
    and other data types.  See Stdio chapter of the documentation for
    more information.

33. New structure intrinsic: set_struct_fields.  This is useful for
    setting the fields of a structure without doing each one
    individually.

34. Interpreter now understands __FILE__ and __LINE__ as referring to
    the file name and line number of the object being parsed.

35. New intrinsic: array_map.  This applies a function to each element
    of an array and returns the result as an array.

36. The documentation for the intrinsic functions has been updated and
    organized into a more coherent form.

37. New interface to C structures.  See the documentation.

38. Modifications to the interpreter integer types so that short and
    int are equivalent whenever sizeof(short)==sizeof(int).  Ditto for
    int and long.  This reduces the code size.

39. NULL is equivalent to 0 in while and if statements, e.g.,

       x = NULL;
       if (x) { never_executed (); }
       while (x) { never_executed (); }

40. `public' made a keyword to for symmetry with `private' and
    `static', e.g.,
      
         public define a_public_function ();
	 public variable a_public_variable;
	 
41. semantics of `implements' modified such that the default variable
    and function declarations are `static', i.e.,
    
        define xxx ();  % ==> public function
	implements ("foo");
	define yyy ();  % ==> static function

42. Patch from Martynas Kunigelis <kunimart at pit.ktu.lt> adding more
    line and symbol drawing characters.  Also a patch from
    k-yosino at inatori.netsweb.ne.jp forcing a flush when disabling
    use of the terminal's status line.

--- Version 1.3.5 released ---

43. Corrected the name of SLang_(sg)et_array_element to be consistent
    with the documentation.

44. Fixed a bug involving orelse and andelse statements when
    _debug_info is non-zero.

45. The _apropos intrinsic modified to work with namespaces.  In fact,
    it now returns an array of matches, or if called with out a
    namespace argument, it returns values to the stack for backward
    compatibility.

46. strchop and strchopr functions modified to return arrays. (this
    changes was actually made in 1.3.5).

47. Semantics of strcompress modified to be more useful.  The new
    semantics are probably more natural and should pose no
    compatibility problems.

48. The `*' operator may be used in array index expressions and is
    equivalent to `[:]', e.g., a[*,1] means all elements in column 1
    of the 2d array.

49. New intrinsics to convert bstrings <--> arrays:
  
        bstring_to_array
	array_to_bstring

50. New timing intrinsics: tic(); toc(); times ();  Also, unix_ctime
    renamed to ctime (This change occurred in 1.3.5).

51. strcat modified to accept more than 2 arguments:

       strcat ("a", "b", ..., "c") ==> "ab...c";

52. %S in format specifiers will convert the object to its string
    representation and use it as %s.

53. strtok defaults to using " \t\r\n\f" if called with one argument.

54. fgetslines takes optional second argument that specifies the
    number of lines to read.

55. If typeof(A) is IStruct_Type, and the corresponding C pointer is
    NULL, then pushing A will result in pushing NULL.  This allows A
    to be compared to NULL.

56. More optimization of arithmetic operations to improve speed.  My
    tests indicate that the resulting code involving arithmetic
    operations are about twice as fast as python (1.5) and about 20%
    faster than perl 5.

57. Patches from Andreas Kraft <kraft at fokus.gmd.de> disabling the
    listdir intrinsic function if compiled with MSC.  Apparantly, the
    MSC compiler does not support posix functions such as opendir
    (although other vendors, e.g, Borland, have no problem with this).

58. `array_sort' intrinsic may be used without a comparison function.
    See docs.

59. Spelling errors in slang.tm corrected by Uichi Katsuta
    <katsuta at cced.mt.nec.co.jp> (Thanks!).

60. Default install prefix changed from /usr to /usr/local

61. Changes made to SLtt/SLsmg code so that when a color definition is
    made via, e.g., SLtt_set_color, then the SLsmg interface will be
    get automatcally notified so that the next SLsmg_refresh will
    produce the correct colors.  In addition, SLsmg_touch_screen added.

62. It is now possible to evaluate S-Lang expressions with the
    S-Lang preprocessor e.g.,
      
        #ifeval (_slang_version > 9900) || (x == 1)

63. sl-feat.h: Patch from Jörg Strohmayer <j_s at gmx.de> to define
    _SLANG_MAP_VTXX_8BIT=1 for AMIGA.

64. New intrinsics: 
      strjoin.  This joins elements of a string array.
      localtime, gmtime

65. New SLsmg function: SLsmg_reinit_smg.  Instead of calling
    SLsmg_reset_smg followed immediately by SLsmg_init_smg when
    processing SIGWINCH signals, call SLsmg_init_smg instead.  This
    will allow SLsmg based code to properly redraw themselves when
    running in a SunOS cmdtool window by working around a bug in
    cmdtool.

===========================================================================

Changes since 1.2.1
 1. slcmd.c was not parsing characters in single quotes correctly,
    e.g., 'a'.

Changes since 1.2.0
 1. Oops.  A NULL pointer could be referenced in slcmd.c.

Changes since 1.0.3 beta

-1. The SLKeyMap_List_Type structure has been modified to allow the
    name of the keymap be be an arbitrary length.  Unfortunately, this
    change breaks backward compatibility.  So, if you have programs
                                               ^^^^^^^^^^^^^^^^^^^^
    that are dynamically linked to previous BETA versions of 1.0, you
    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    will have to recompile those applications!!!
    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

0. The variable SLsmg_Newline_Moves has been renamed to
   SLsmg_Newline_Behavior with the following interpretation:
#define SLSMG_NEWLINE_IGNORED	0      /* default */
#define SLSMG_NEWLINE_MOVES	1      /* moves to next line, column 0 */
#define SLSMG_NEWLINE_SCROLLS	2      /* moves but scrolls at bottom of screen */
#define SLSMG_NEWLINE_PRINTABLE	3      /* prints as ^J */

1. Added patches from Joao Luis Fonseca <joaolf at centroin.com.br> 
   to src/mkfiles/makefile.all and a necessary OS/2 specific
   declaration to slvideo.c.  I also added the Watcom patches from
   Bill McCarthy <WJMc at pobox.com> to makefile.all.
2. The terminfo code is now aware of the complete set of terminfo
   definitions.  However, the screen management routines support a
   small subset. (Eric W. Biederman <ebiederm+eric at npwt.net>).
3. Improvements to the SLsmg scrolling alogorithm.
4. SLang_process_keystring and SLang_make_keystring now return NULL upon
   failure.
5. SLcomplex_sqrt branch cut modifed to be consistent with FORTRAN.
6. If the system supports vsnprintf and snprintf, they are used.  The
   assumption is that they return EOF upon failure.  My linux man page
   for these functions have conflicting statements regarding this.

7. Simplified handling of memory managed types.  Now it is possible to
   pass the managed object directly to the intrinsic function.  See
   slfile.c for an explicit example of this technique.  Similarly,
   references may also be passed and the function SLang_assign_to_ref
   may be used to assign values to the referenced object.  This is
   also illustrated in slfile.c.

8. QNX specific tweak to slfile.c from Pavanas Abludo Incusus
   <pavanas at ccia.com>.

9. Fixed a problem where, e.g., 

        x = Double_Type [7,8,9];
	y = x[0,[:],[:]];
   
   returned y = Double_Type[8*9] instead of the more intuitive result
   Double_Type[8,9];

10. SLcmd_Cmd_Table_Type structure changed to permit an unlimited
    number of arguments.  The changed should be backward compatible
    except that a recompilation of the application will be necessary.
11. New SLsmg function: SLsmg_set_color_in_region may be used to set
    the color of a specified region.  See demo/smgtest.c for an
    example of how this is used.  Another use would be to draw shadows
    around a box.
12. OS2 ICC patches from Eddie Penninkhof <eddie.penninkhof at tip.nl>.
13. Grammar tweaked to make the pow (^) operator postfix-unary.  This
    makes more sense mathematically so that:
    
        a^b^c ==> a^(b^c);
	-(a)^b ==> -(a^b);

14. New struct specific intrinsics:

       get_struct_field_names
       get_struct_field_value
       _push_struct_field_values

    See function reference for more information on these.

Changes since 1.0.2 beta
0. SLtt_init_video, SLtt_reset_video, SLsmg_resume_smg,
   SLsmg_suspend_smg have been modifed to return 0 upon success, or -1
   upon error.
1. Configure script modified to report slang version as 1.0.x instead
   of 1.0.0x.
2. Bug fix involving automatic detection of color (Unix)
3. slvideo.c bug fixed (WIN32, Thanks Chin Huang <cthuang at vex.net>)
4. Slsignal modified so that fork is not used for CYGWIN32, suggested
   by vischne at ibm.net.
5. Solaris ELF patches integrated into configure.in.  Now ELF support
   is available for Linux and Solaris.  Thanks Jan Hlavacek
   <lahvak at math.ohio-state.edu>.
6. The library now works with MING32 and should work with CYGWIN as
   well.  See INSTALL.pc and src/mkfiles/README for more information.
   Do NOT use the configure script under these environments.
7. A new IBMPC_SYSTEM function added that affects WIN32, MSDOS, and
   OS/2 systems: 
     
         SLang_getkey_map_to_ansi (int enable);
	 
   If `enable' is non-zero, arrow and function keys will be mapped to
   the ansi equivalents.
8. The WIN32 terminal support has been modified to be more consistent with
   the other platforms.  In particular, mouse button press reporting
   has been added (SLtt_set_mouse_mode), and bright color support
   appears to have been fixed.  Note: For MINGW32 and CYGWIN32, use
   src/mkfiles/makefile.all.  Do not use the Unix configure script
   because WIN32 is NOT Unix.
9. Several changes to slvideo.c that deals with the proper use of the
   scroll region for DOS/Windows type systems.
10. demo/smgtest.c has been enhanced.
11. Some cleanup performed to src/slprepr.c
12. WIN32 and WIN16 preprocessing symbols are defined when appropriate.


Changes since 1.0.1 beta
1. More VMS patches.  Thanks Andy.

Changes since 1.0.0 beta
1. Fixed a bug in the automatic detection of color terminal
2. Patches to get it to compile on OS2 and VMS
3. Replaced \r\n in slarray.c with \n

Changes since 0.99-38
0. Many, many changes to the interpreter.  See documentation.

1. SLang_free_intrinsic_user_object shortened via define on VMS.
2. Make sure slang.h does not defined REAL_UNIX_SYSTEM on OS/2.
3. New search paths for termin directories include $HOME/.terminfo and
   /usr/share/terminfo.
4. SLsystem function added.  This is a replacement for `system'.  It 
   implements POSIX semantics for POSIX systems.  Although Linux
   claims to be a POSIX system, it's `system' routine is broken.
5. color names color0 ... color7, brightcolor0, ... brightcolor7
   added for Unix and VMS systems.

Changes since 0.99-37
1. SLang_input_pending returns -1 if Ctrl-Break pressed (DOS specific).
2. SLtty_VMS_Ctrl_Y_Hook added for Ctrl-Y trapping.  Keep in mind that
   this is called from an AST.
3. Documentation updates
4. Fixed bug dealing with keymaps with escape sequences involving
   characters with the high bit set.
5. slkeypad code ported to DOS
6. SLsmg_write_raw and SLsmg_read_raw functions added.
7. Compilation error under QNX fixed.
9. Small change involving SLang_flush_input.


Changes since 0.99-36
1. Oops fixed a bug in alternate character set handling when
   SLtt_Use_Blink_For_ACS is set.  This bug only affected DOSEMU.
2. slvideo.c modification that affects DJGPP version of library.  Now
   the screen is saved and restored.
3. Updates to slcurses.c by Michael Elkins.
4. If a color called `default' is specified, the escape sequence to
   set the default color will be sent.  Be careful, not all terminals
   support this feature.  If your terminal supports it, e.g., rxvt,
   then using
   
        setenv COLORFGBG default
     
   is a good choice.

Changes since 0.99-35
1. Fixed alt char set bug introduced in 0.99-35.
2. New intrinsic: _stk_reverse
3. New demos: keypad, smgtest, pager
4. The environment variable COLORFGBG may be used to specify default
   foreground background colors, e.g., in csh use:
   
        setenv COLORFGBG   "white;black"
	
   to specify white on black as the default colors.  This also means
   that a color name of NULL or the empty string "" will get mapped to
   the default color.
5. Improved curses emulation provided by Michael Elkins
   (me at muddcs.cs.hmc.edu).
6. Small bug fix to SLang_flush_output provided by Balakrishnan k
   <MDSAAA27 at giasmd01.vsnl.net.in>.
7. Updated some documentation in doc/cslang.tex (Gasp).
8. Update vmsmake.com file provided by Martin P.J. Zinser
   (m.zinser at gsi.de).

Changes since 0.99-34
0. OS/2 video problem solved by Rob Biggar (rb14 at cornell.edu).

1. The way the interpreter internally handles strings has changed.
   This should not affect programs which utilize the library.  Now all
   strings returned by the function SLang_pop_string should be freed
   after use.  The SLang_pop_string function will always set the value
   of the second parameter passed to it to a non-zero value.  For this
   reason, programs should use the new function SLpop_string and
   always free the string returned by it after use.

2. If SL_RLINE_NO_ECHO bit is set in the readline structure, the
   user response will not be echoed.
   
3. If terminal is xterm, the TERMCAP environment variable will be
   ignored.  This change was necessary because of the braindead
   TERMCAP setting created by the latest version xterm.
   
4. Some of the keymap routines were re-coded.  Now it is possible to
   have lowercase characters as part of the prefix character sequence.

5. New modules.  See demo/pager.c for information.  See also the slrn
   source code for a more sophisticated use.

      SLscroll: may be useful for routines that deal with displaying
                linked lists of lines.
      SLsignal: POSIX signal interface for programs that use SLsmg and
                SLtt modules.  doc/signal.txt may also prove useful.
      SLkeypad: Simplified interface to SLang keymaps.
      SLerrno:  System independ errno routines

Changes since 0.99-33
1. A couple of interpreter bug fixes.

2. Some macros, e.g., MEMSET, removed from slang.h.  I do not feel
   that they belong there and it is unlikely that they are used by
   others.  I made them avalable in the file src/jdmacros.h for anyone
   whose code depends on them.
   
3. The functions jed_mem??? have been renamed to SLmem???.

4. New intrinsic: _obj_type returns type information about object on top
   of stack.

Changes since 0.99-32
1. appropriate header files added for VMS
2. Oops.  0.99-32 introduced a bug positioning cursor. :(

Changes since 0.99-31
1. Simple minded curses emulation added.  This should help those migrating
   from curses.  See slang/src/curses/*.c for sample curses demo programs
   that the SLsmg routines can handle.  See also slang/src/slcurses.c for
   some wrapper functions.
2. Changed <config.h> to "config.h" in all source files.
3. If system lacks terminfo directories, it is compiled with termcap
   support.  This generalizes and replaces the test for NeXT.   
4. New functions for slang/src/sldisply.c:

    void SLtt_get_screen_size (void);
    SLtt_Char_Type SLtt_get_color_object (int);
    void SLtt_set_color_fgbg (int, SLtt_Char_Type, SLtt_Char_Type);
    
   The first function attempts to deduce the correct values of
   SLtt_Screen_Rows and SLtt_Screen_Cols.  This function is called by
   sltt_get_terminfo.
   
   New constants such as SLSMG_COLOR_BLACK, SLSMG_COLOR_RED, ... have been
   added to slang.h to facilitate the use of SLtt_set_color_fgbg.

5. Improved error messages
6. ELF support.  Do: make elf; make install-elf

Changes since 0.99.30

1. Small bug fixed that affects 64 bit machines with a certain byte
   ordering.   
2. slutty.c: _POSIX_VDISABLE is used if defined.

Changes since 0.99.29

0. BIG change in handling keymaps.  Specifically, this change effects the
   change of the `f' field of the SLang_Key_Type structure.  Before, this
   was VOID_STAR, now it is a union.  The new change is much more portable.
   In addition, the function `SLang_define_key1' has been removed and
   replaced by `SLkm_define_key'.  See src/slrline.c for the use of this new
   interface.  For a short time, the old interface will be available if the
   preprocessor symbol `SLKEYMAP_OBSOLETE' is defined when slang is compiled.
   See jed and slrn source for more examples.  
   
1. SLang_getkey now reads from /dev/tty (unix).
2. If the first argument to SLang_init_tty is -1, the current value of the
   interrupt character will not be changed (unix).
3. New intrinsic: time
Changes since 0.99.28
1.  Oops! Horrible bug in src/slmemcmp fixed.
2.  slvideo: init_video modified to be more consistent with VMS/Unix routine.

Changes since 0.99.27
1.  More changes to the configure script
2.  It looks like hpterm support is in place.  This terminal has a glitch
    that prevents efficient screen updating.
3.  New SLsmg function: 
     
     void SLsmg_write_color_chars (unsigned short *s, unsigned int len)
     
    This function may be used to write a string of characters with
    attributes.

Changes since 0.99.26
1.  Slang now uses a configure script under Unix to configure itself.
2.  New intrinsic functions include _stk_roll, strchop, strchopr.
3.  Terminals which require an escape sequence to make their arrow keys work
    are now sent the escape sequence.

Changes since 0.99.25
1.  New SLsmg variables:
     SLsmg_Newline_Moves
     SLsmg_Backspace_Moves
    These variables control the interpretation of newline and backspace
    characters in smg.     

Changes since 0.99.24
1.  SLSMG_RTEE_CHAR, etc... added to OS/2 part of slang.h
2.  Small fix for aix-term

Changes since 0.99.23
0.  The makefile for unix has been completely re-written. 
1.  Some problems dealing with certain color terminals have been resolved.
2.  `g' generic type added to SLcmd.

Changes since 0.99.22
0.  The Macro `VOID' has been removed.  The whole point of this macro was to
    mimick `void *' declarations for compilers that did not support such a
    construct.  Instead of `VOID *', slang.h now defines `VOID_STAR' and all
    `VOID *' declarations have been renamed to `VOID_STAR'.  
    
    If you use the VOID macro in your application, you have two choices: 
    
       1.  Rename all occurances of VOID * to VOID_STAR
       2.  Add: #define VOID void somewhere appropriate.

1.  \< and \> regular expressions added.

Changes since 0.99.21
1.  Oops.  I added too much linux stuff (see 3 below).  Some of it backed
    out to Linux only.

Changes since 0.99.20
1.  Problem on some VMS systems which lack prototype for atof fixed.
2.  New function: SLtt_set_mouse_mode.  This is used to turn on/off mouse
    reporting on Unix and VMS systems.
3.  The terminal type `linux' is now recognized by the SLtt interface---
    even if there is no termcap/terminfo entry for it.

Changes since 0.99.19
1.  User definable types must now have object identification numbers larger 
    than 127.  The lower limit used to be 100 but this comflicts with many 
    applications (as well as slang itself) using lower case letters as the
    object number, e.g., create_array ('s', 10, 1); which creates an array
    of 10 strings (object number 's' = 115).

2.  New intrinsic: array_info available.
3.  regular expression matching bug involving \{m,n\} expressions fixed.
4.  New module: slprepr.c.   This gives programs the ability to use the slang
    preprocessor.
5.  News slsmg functions: SLsmg_suspend_smg () and SLsmg_resume_smg ().
    These are designed to be used before and after suspension.  The SLsmg
    state is remembered and a redraw is performed by the resume_smg function.
6.  The function `sltty_set_suspend_state' is now available for Unix
    systems.  It may be used to turn on/off processing of the suspend
    character by the terminal driver.
7.  If SLtt_Try_Termcap is 0, the TERMCAP variable will not be parsed.
8.  SLang_TT_Read_FD variable is now available for unix.  This is the file
    descriptor used by SLang_getkey.
9.  New preprocessor symbols available:
     SLMATH      : If math functions are available
     SLUNIX      : If unix system calls are available
     SLFILES     : Stdio functions available
     FLOAT_TYPE  : Floating point version
     
Changes since 0.99.18
1.  New intrinsic function: strcompress.  This collapses a string by removing
    repeated characters.  For example,
    
           define collapse (f)
	   {
	      while (str_replace (f, " ", ",")) f = ();
	      return strcompress (f, ",");
	   }

           collapse (",  ,a b c ,,,d e,f  ");
      
    returns: "a,b,c,d,e,f"
    
2.  QNX support added.  
3.  New Functions (unix only): SLtt_tgetstr, SLtt_tgetnum, SLtt_tgetflag.
4.  Fixed parsing of Octal and Hex numbers so that incorrect values are
    flagged as errors.  Also, both lower and uppercase values may be used in
    HEX numbers, e.g., 0xa == 0XA == 0Xa == 0xA.
5.  MS-Windows support added.  Compile using makefile.msw.  This creates
    `wslang.lib'.
6.  New SLsmg functions:  SLsmg_get_row, SLsmg_get_column.  These return the
    current position.

Changes since 0.99.17
1.  I have added limited termcap support although slang is still a terminfo
    based system.  The support is provided via the TERMCAP environment
    variable.  If this variable exists and contains a termcap entry for which
    there is no reference to another entry (via tc field), it will be used 
    to setup the terminal.   If the TERMCAP variable does not exist, or it 
    refers to a file, terminfo is used instead.  This is not really a
    limitation since one can set this variable in a way that slang likes by
    using `tset -s'.
    
    The motivation for this support is two-fold:
       a. Slang programs can now run inside the screen program which sets
          the TERMCAP variable appropriately.
       b. A user can now correct defective termcap entries (e.g., for Linux),
          and have those corrections made available to slang via the `tset' 
	  command, e.g., by putting something analogous to:
	     
	       setenv TERMCAP /corrected/termcap/file/absolute/path/name
	       eval `tset -s terminal-name`
	       
	  in the .login file.
       c. This also means that I can distribute corrected termcap entries for
          common terminals.
	  
Changes since 0.99.16
1.  Inadequate terminfo entries for `linux' terminal are compensated for.
2.  Terminals with the ``Magic cookie glitch'' are flagged as having an
    unusable highlighting mode.

changes since 0.99.15
1.  Better checking of parameters passed to search routines.
2.  Problem with line drawing characters fixed.

changes since 0.99.14
1.  Ran code through purify.  Fixed one problem reported in slkeymap.c
2.  Fixed a bug in sldisply.c regarding mono-attributes.
3.  Code ready for ELF
changes since 0.99.13
1.  SLtt_Has_Alt_Charset variable added to xterm.c.  This is motivated by the
    sad, pathetic fact that although some termcap/terminfo databases suggest 
    that the terminal can do line drawing characters, the terminal cannot.
2.  SLsmg_write_nstring function added.  This function may be used to write
    only n characters of a string padding wit hblanks if necessary.
3.  If the environment variable COLORTERM exist, SLtt_get_terminfo will set 
    SLtt_Use_Ansi_Colors to 1.
4.  Sltt_set_cursor_visibility function added.  If passed a zero integer value,
    the cursor is hidden; otherwise, it is made visible.
    
changes since 0.99.12
1.  SLsmg now uses the `te' and `ti' termcap entries if present.  Apparantly
    some terminals need to be put in cursor addressing mode.  This also has
    the effect of restoring the screen of the xterm to what it was before
    the program was executed.
2.  For some types of code, slang is 20% faster!  This is especially
    noticeable for branching constructs inside tight loops or recursive
    functions.
    
changes since 0.99.10
1. New version control added:
    
    A new preprocessor symbol was added: SLANG_VERSION
    This is a 6 digit integer of the form: abcdef 
    This corresponds to version number ab.cd.ef.  So for version 0.99.11:
    #define SLANG_VERSION 9911
    
    In addition, the intrinsic variable `SLang_Version' was changed from a 
    string to an integer that has the value SLANG_VERSION.  This also implies
    that the interpreter variable _slang_version is now an integer.

changes since 0.99.9
1. The terminfo code failed to recognize the automatic margin flag.  This
   has been corrected.  In addition, the display code nolonger resets the
   character set upon initialization.  This is considered to be a good thing.

2. There is a new program in slang/doc called `texconv' that will produce a
   nicely formatted ascii document from the tex formatted ones.  In
   addition, new documentation has been added: slang.tex which describes the
   syntax of the slang programming language and cslang.tex which describes
   the C interface to the library.  The latter document is far from complete
   but it is a start.
   
3. A new variable declaration keyword has beed added: global_variable
   This keyword is useful for declaring global variables from within
   functions.  Such a feature simplifies some scripts.
   
4. The SLsmg line drawing functions are now in place.
   
changes since 0.99.8
1. \d may now be used in regular expressions to specify a digit.  In addition,
   \e specifies an escape character.  So for example, `\e\[\d;\dH' matches
   an ANSI cursor position escape sequence.
2. Small bug in dealing with terminals that have automatic margins has been
   fixed.
3. When compiled with -DSLANG_TERMINFO will use terminfo.  This means that
   there is no need to link to termcap.
   
changes since 0.99.7
1. New function added to the readline package:
     int SLang_rline_insert (char *s);
   this may be used to stuff strings into the rline buffer.  SLSC exploits
   this feature.

changes since 0.99.6

1. ALL macros beginning with LANG have been changed to use SLANG as the
   prefix.  For example, the macro LANG_IVARIABLE has been renamed to
   SLANG_IVARIABLE.  If you have used one of these macros, please make the
   change.
   
2. Application defined types.  See demo/complex.c for an example that
   defines complex numbers and overloads the binary and unary operators to
   work with them.
   
changes since 0.99.5


1. New interface for application defined objects.  Functions include:

   extern SLuser_Object_Type *SLang_pop_user_object (unsigned char);
   extern void SLang_free_user_object (SLuser_Object_Type *);
   extern void SLang_push_user_object (SLuser_Object_Type *);
   extern SLuser_Object_Type *SLang_create_user_object (unsigned char type);
				

  This means that S-Lang scripts do not have to worry about freeing
  structures, arrays, etc...  A consequence of this fact is that the
  intrinsic function `free_array' has been removed.  See examples of this
  exciting new feature in slang/demo.
  
2. Better documentation and examples.  See slang/doc/*.* as well as examples
   in slang/demo.
  
3. Memory allocation macros have changed from MALLOC to SLMALLOC, etc...
   Applications are encouraged to use these rather than `malloc' because by
   compiling your application AND the slang library with the -DMALLOC_DEBUG
   will link in code that checks if you have corrupted memory, freed
   something twice, etc...  Use the function `SLmalloc_dump_statistics' for
   a report of memory consumption by your program.
   
changes since 0.99.4
1. cleaned up the source some and I changed the names of the hooks
   user_whatever to `SLang_User_Whatever'.  This makes them more consistent
   with other external functions and variables and helps avoid name space
   pollution.
changes since 0.99.3
* added screen management stuff
* added a new help file reader (see help directory)
* DOUBLE precision is now the default.  I think that this makes more sense
  for an interpreted langauge.
* searching routines added.
changes since 0.99.2
* added low level tty support for VMS, DOS, and Unix
* slang readline added
* keymap support
* files restructured so that programs can link, say, the readline library
   and not get the whole interpreter linked in.
   
changes since 0.99.1
*  obscure bug in regular expression fixed
*  optimizing performed for 10% speed increase in speed for some language
     constructs

changes since 0.99.0
*  semantics of the `switch' statement changed to be more C-like with the
   addition of the `case' keyword.  For example, one can write:
   
        switch (ch)
	{ case 'A':  
	    something ();
	}
	{ 
	  case 'B':  
	    something_else ();
	}
	{ case 3.14: 
	    print ("Almost PI");
	}
	{ case "hello":  
	    print ("hi");
	}
   
   Note that one may mix data types without the possibility of a type
   mismatch error. 
   
changes since 0.98:
*  matrix package added.  Currently only matrix multiplication and addition
   is supported.  More functions will be added (determinants, inverse, etc..)
   This support is provided by the `init_SLmatrix ()' call.  This support 
   provides the following S-Lang intrinsics:
   
         matrix_multiply, matrix_add
	  
   
*  New S-Lang core intrinsic:

         copy_array  :  copys the contents of one array to another

changes since 0.97:
 
*  Double precision floating point supported.  
   Use the -DFLOAT_TYPE -DUSE_DOUBLE compiler flags to enable this.
   Note that S-Lang does not support single precision and double precision
   floating point number SIMULTANEOUSLY.  You must choose one or the other
   and stick with it!
   
*  Byte compiling is now more than simple preprocessing.  This results in
   about a 20% decrease in loading time.  This also means that if you
   rebuild your application, you MUST re-bytecompile.
   
*  New syntax added:  Consider a function f that returns multiple values.
   Then to assign these values to, say var_1, and var_2, simply write:
   
       (var_1, var_2) = f ();
       
    This is an alternative to:  
    
        f (); =var_2; =var_1;
	
Changes since 0.96:

  It is now possible to use short circuit boolean evaluation of logical
  expressions is the `orelse' and `andelse' constructs.  Previously, these
  constructs were only available at the infix level.  The new syntax looks
  like (example taken from JED's rmail.sl):
  
     if (orelse 
	 {re_bsearch("^\\CFrom:.*<\\(.+\\)>");}
	 {re_bsearch("^\\CReply-To: *\\([^ ]+\\) *");}
	 {re_bsearch("^\\CFrom:.*<\\(.+\\)>");}
	 {re_bsearch("^\\CFrom: *\\([^ ]+\\) *");}
	 {re_bsearch("^\\cFrom +\\([^ ]+\\) *");}
       )
     {
	from = rmail_complex_get_from(from);
     }
     

  Modified some of the array code to use handles to arrays instead of actual
  arrays.  This adds alot more protection for the use of arrays.  The
  downside is that there is a limit on the number of active arrays.  This
  limit has been set to a default value ot 256.  An ``active'' array is an
  array that has been created but not freed.
  
  Fixed a parse error that occurred when an `if' statement imediately follow
  the `:' in a switch statement.
  
  putenv intrinsic added.

  EXIT_BLOCK:  if an exit block is declared, it is called just before the
               function returns to its caller. 

It is now possible to perform assignments in variable declaration
statements, e.g.,

variable i = 0, imax = 10, n = strlen (name);

Condition compilation of S-Lang source possible.  See .sl files in the jed
distribution.

A bug which prevent assignment to a global C floating point variable was
fixed. 

Changes to `calc':

   `apropos' function added to calc.sl.  For example, `apropos("str")'
      creates a list of all intrinsic functions that contain the substring
      "str"  (strcmp, strcat, etc...)
      
    Command line arguments are now loaded as S-Lang source files.  This makes
      it possible to create a Unix executable such as:
      
         #! /usr/local/bin/calc
	 
	 define hello_world () { print ("hello world"); }
	 loop (10) hello_world ();
	 quit ();
}}}
