Release 0.9.9

Bug fix and enhancements

• New features
• More R7RS-large and SRFI support
• Charset enhancements to Full Unicode range
• Macro tracer
• Checking use of undefined result in conditionals
• Improvements
• Bug fixes
• Potential incompatibilities

New features

More R7RS-large and SRFI support

• scheme.stream: Streams (formerly srfi-41).
• scheme.ephemeron: Ephemeron (formerly srfi-124).
• scheme.regex: Scheme Regular Expression (formerly srfi-125). Contributed from @pclouds. Grapheme support is still missing.
• scheme.vector.u8 etc.: Homogeneous numeric vector libraries (srfi-160).

• srfi-162: Comparators sublibrary.
• srfi-173: Hooks.

Charset enhancements to Full Unicode range

• Predefined char-sets (srfi-14) are enhanced to the entire Unicode range, e.g. char-set:digit now includes all Unicode characters with general category Nd. If you want to limit the range to ASCII, there are corresponding char sets (e.g. char-set:ascii-digit) provided.
• 'Umbrella' general category char-set: char-set:L includes characters from general categories that begin with L, etc.
• In regexps and char-set literals, you can use \p{category} and \P{category}, where category is Unicode general category, e.g. Lu.
• The \d, \w, \s in regexp and char-sets are still limited to ASCII range, for changing them would likely to break existing code.
• POSIX notation [:alpha:] etc., also covers ASCII range only. To cover full Unicode, you can use [:ALPHA:] etc.

Macro tracer

• trace-macro: You can now trace macro expansion.

Checking use of undefined result in conditionals

• Return value of procedures that return "undefined result" shouldn't be used in portable code. However, Gauche usually returns #<undef> from such procedures, and it counts to true as a boolean test in conditionals. We found quite a few code that branches based on the result of undefined return value. Such code is fragile, for it may break with unintentional change of return values of such procedures. Gauche can now warn such cases when the environment variable GAUCHE_CHECK_UNDEFINED_TEST is set. See the blog entry and Undefined%20values.

Improvements

• Partial continuation support is overhauled w.r.t interaction with dynamic environment and full continuations. Contributed by @Hamayama.
• gauche.uvector: Support uniform complex vectors (c32, c64 and c128).
• gauche.test: New compile-only option to test-script, so that it can perform syntax check without executing the actual script (useful if the script is written without using main).
• gauche.generator: Add negative step value support to grange.
• regexp-replace etc.: It used to be an error when regexp matches zero-length string. Which wasn't wrong, but in practice it was annoyance. Now if regexp matches zero-length string we advance one character and repeat matching. This behavior is also adopted by Perl and Ruby.
• gosh -h now emits help messages to stdout and exits with 0.
• Experimental line editor: backward-word and forward-word added by @pclouds https://github.com/shirok/Gauche/pull/524

Bug fixes

• Keyword argument handling wasn't hygienic.
• pprint: Prettyprint emits negative labels ( https://github.com/shirok/Gauche/issues/484 )
• Extend the limit of environment frame size ( https://github.com/shirok/Gauche/issues/487 )
• Scm_CharSetAdd could yield inconsistent result when you add an ASCII character to a large charset. Patch by @pclouds https://github.com/shirok/Gauche/pull/500
• import: Only/rename import qualifiers didn't work with transitiev export ( https://github.com/shirok/Gauche/issues/472 )
• Some system calls shouldn't be restarted when interrupted. https://github.com/shirok/Gauche/issues/504
• format: ~vr didn't work. https://github.com/shirok/Gauche/issues/509
• sort!, stable-sort!: We implemented them as if they were linear-updating, that is, we didn't guarantee if the argument still pointed to the head of the sequence after the call. However, srfi-95 didn't explicitly mentions linear updating semantics, so we guaranteed that caller can call them purely for side-effects.

Potential incompatibilities

• Scm_RegExec now takes two more arguments specifying start and end of the range of input string. I overlooked this change and missed to add a proper transition macro. You can use #ifdef SCM_REGEXP_MULTI_LINE to switch the new interface vs the old one.
• Toplevel define now inserts a dummy binding at compile-time (as a result of https://github.com/shirok/Gauche/issues/549 ). It is consistent with the specification, but existing code that relied on undefined behavior might be affected. See the blog entry.
• The (scheme base) library inadvertently exported Gauche's define instead of R7RS define; Gauche's define recognizes extended lambda arguments, while R7RS's not. This was a bug and fixed now, but if your R7RS code happens to use Gauche's extended argument notation, it'll break.
• macroexpand: Now it strips syntactic information from the return values (with renaming macro-inserted identifiers, so that different identifiers with the same name won't be confused). This generally improves interactive use when you check how macros are expanded. If you're using the output of macroexpand programatically, this may break hygiene; you can pass an optional argument to preserve syntactic information.
• parser.peg: This module is still unofficial, but in case you're using it: $do is now obsoleted. Use $let and $let*. $parameterize is added by @SaitoAtsushi.