diff options
author | Andy Wingo <wingo@pobox.com> | 2010-03-23 20:23:19 +0100 |
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committer | Andy Wingo <wingo@pobox.com> | 2010-03-30 10:31:27 +0200 |
commit | d38b431ace4b01e5da9cb09bb6341277f2974160 (patch) | |
tree | 745db83549f083455e0ac4e96058da3e67acbba7 /libguile/boolean.h | |
parent | 655aadf4b09c40f4c7854e4325e8809fcb7cb36b (diff) | |
download | guile-d38b431ace4b01e5da9cb09bb6341277f2974160.tar.gz |
nil is false, whee
* libguile/boolean.h (scm_is_false): Recognize nil as false, by default.
(scm_is_bool): Recognize nil as a boolean.
* libguile/boolean.c (scm_not, scm_boolean, scm_to_bool, scm_is_bool):
Adapt to treat nil as false.
* libguile/vm-i-system.c (br-if, br-if-not): Just use scm_is_false
instead of specifically mentioning nil.
Diffstat (limited to 'libguile/boolean.h')
-rw-r--r-- | libguile/boolean.h | 11 |
1 files changed, 6 insertions, 5 deletions
diff --git a/libguile/boolean.h b/libguile/boolean.h index bc108f5c3..007500e10 100644 --- a/libguile/boolean.h +++ b/libguile/boolean.h @@ -27,7 +27,9 @@ -/* Boolean Values +/* Boolean Values. Obviously there are #t and #f, but there is also nil to deal + * with. We choose to treat nil as a false boolean. All options might silently + * break existing code, but this one seems most responsible. * */ @@ -58,8 +60,8 @@ #endif #define scm_is_true_and_not_nil(x) (!scm_is_false_or_nil (x)) -/* XXX Should these macros treat %nil as false by default? */ -#define scm_is_false(x) (scm_is_false_and_not_nil (x)) +/* %nil is false. */ +#define scm_is_false(x) (scm_is_false_or_nil (x)) #define scm_is_true(x) (!scm_is_false (x)) /* @@ -90,8 +92,7 @@ SCM_API int scm_is_bool (SCM); -/* XXX Should scm_is_bool treat %nil as a boolean? */ -#define scm_is_bool(x) (scm_is_bool_and_not_nil (x)) +#define scm_is_bool(x) (scm_is_bool_or_nil (x)) #define scm_from_bool(x) ((x) ? SCM_BOOL_T : SCM_BOOL_F) SCM_API int scm_to_bool (SCM x); |