* Renumbers the IFLAG constants.
* Adds several macros related to boolean type tests, null tests, and
boolean-truth testing (including lisp-style boolean-truth tests).
* Adds compile-time checks to verify the necessary IFLAG numbering
properties needed for the checks to work properly.
* Changes some existing code to use the new optimized macros, without
changing the semantics of the code at all (except that scm_is_bool
is changed from a function to a macro).
I added the following macros, whose names explicitly state how %nil
should be handled. See the comments in the patch for more information
about these.
scm_is_false_assume_not_lisp_nil scm_is_true_assume_not_lisp_nil
scm_is_false_and_not_lisp_nil scm_is_true_or_lisp_nil
scm_is_false_or_lisp_nil scm_is_true_and_not_lisp_nil
scm_is_lisp_false scm_is_lisp_true
scm_is_null_assume_not_lisp_nil
scm_is_null_and_not_lisp_nil
scm_is_null_or_lisp_nil
scm_is_bool_and_not_lisp_nil
scm_is_bool_or_lisp_nil
The following already-existing macros are defined as aliases, such
that their semantics is unchanged (although scm_is_bool used to be a
function and is now a macro).
scm_is_null --> scm_is_null_and_not_lisp_nil
scm_is_false --> scm_is_false_and_not_lisp_nil
scm_is_true --> scm_is_true_or_lisp_nil
scm_is_bool --> scm_is_bool_and_not_lisp_nil
(I still believe that these should be changed to versions that handle
%nil properly, but await approval on that point, so these patches do
not make those changes)
Also, if the preprocessor macro SCM_ENABLE_ELISP is not true (this
macro already existed and was used in lang.h), all overheads
associated with %nil handling are eliminated from the above macros.
* libguile/tags.h (SCM_BOOL_F, SCM_BOOL_T, SCM_UNSPECIFIED)
(SCM_UNDEFINED, SCM_UNBOUND, SCM_ELISP_NIL): Renumber, so that a
number of important distinctions (false versus true, end-of-list, etc)
can be made by masking a single bit. Also define a number of
build-time tests to assert that this condition holds.
* libguile/boolean.h (scm_is_false_and_not_nil, scm_is_true_or_nil)
(scm_is_false_assume_not_nil, scm_is_true_assume_not_nil):
(scm_is_false_or_nil, scm_is_true_and_not_nil)
(scm_is_bool_or_nil, scm_is_bool_and_not_nil): New exciting macros to
test certain boolean/end-of-list properties.
(scm_is_false, scm_is_true): Use a restrictive definition, where only
SCM_BOOL_F is false. Should probably change in the future.
(scm_is_bool): Incompatible change: changed to be a macro. Was a
function before. Probably should allow nil as a boolean, but that will
be for a later patch.
(scm_is_lisp_false, scm_is_lisp_true): New macros, implementing the
standard Lisp boolean predicates, where '() is actually false.
* libguile/eval.i.c (CEVAL): Fix a number of false-or-nil and similar
tests to use the new macros.
* libguile/lang.h (SCM_NULL_OR_NIL_P): Use scm_is_null_or_nil.
* libguile/pairs.c: Add a compile-time check that null and nil differ by
only one bit.
* libguile/pairs.h (scm_is_null_and_not_nil, scm_is_null_assume_not_nil)
(scm_is_null_or_nil): New exciting macros!
(scm_is_null): Just be scm_is_null_and_not_nil, for now.
* libguile/print.c: Adapt to the reordering, and print suitably nasty
things for the not-to-be-used values.
added append docs from R4RS.
* strings.c: Docstring typo fix, + eliminate unneeded IMP tests.
Thanks Dirk Hermann!
* chars.h: Provide SCM_CHARP, SCM_CHAR, SCM_MAKE_CHAR and
deprecate SCM_ICHRP, SCM_ICHR, SCM_MAKICHR. Thanks Dirk Hermann!
* *.h, *.c: Use SCM_CHARP, SCM_CHAR, SCM_MAKE_CHAR throughout.
Drop use of SCM_P for function prototypes... assume an ANSI C
compiler. Thanks Dirk Hermann!
