diff options
author | Andy Wingo <wingo@pobox.com> | 2010-03-23 20:23:19 +0100 |
---|---|---|
committer | Andy Wingo <wingo@pobox.com> | 2010-03-30 10:31:27 +0200 |
commit | d38b431ace4b01e5da9cb09bb6341277f2974160 (patch) | |
tree | 745db83549f083455e0ac4e96058da3e67acbba7 | |
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.
-rw-r--r-- | libguile/boolean.c | 13 | ||||
-rw-r--r-- | libguile/boolean.h | 11 | ||||
-rw-r--r-- | libguile/vm-i-system.c | 4 |
3 files changed, 14 insertions, 14 deletions
diff --git a/libguile/boolean.c b/libguile/boolean.c index 3391d6ce5..7d58582a2 100644 --- a/libguile/boolean.c +++ b/libguile/boolean.c @@ -56,28 +56,27 @@ verify (SCM_VALUES_DIFFER_IN_EXACTLY_TWO_BIT_POSITIONS \ SCM_DEFINE (scm_not, "not", 1, 0, 0, (SCM x), - "Return @code{#t} iff @var{x} is @code{#f}, else return @code{#f}.") + "Return @code{#t} iff @var{x} is false, else return @code{#f}.") #define FUNC_NAME s_scm_not { - return scm_from_bool (scm_is_false_or_nil (x)); + return scm_from_bool (scm_is_false (x)); } #undef FUNC_NAME SCM_DEFINE (scm_boolean_p, "boolean?", 1, 0, 0, (SCM obj), - "Return @code{#t} iff @var{obj} is either @code{#t} or @code{#f}.") + "Return @code{#t} iff @var{obj} is @code{#t} or false.") #define FUNC_NAME s_scm_boolean_p { - return scm_from_bool (scm_is_bool_or_nil (obj)); + return scm_from_bool (scm_is_bool (obj)); } #undef FUNC_NAME int scm_to_bool (SCM x) { - /* XXX Should this first test use scm_is_false_or_nil instead? */ - if (scm_is_eq (x, SCM_BOOL_F)) + if (scm_is_false (x)) return 0; else if (scm_is_eq (x, SCM_BOOL_T)) return 1; @@ -93,7 +92,7 @@ int scm_is_bool (SCM obj) { /* This must match the macro definition of `scm_is_bool ()'. */ - return scm_is_bool_and_not_nil (obj); + return scm_is_bool_or_nil (obj); } 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); diff --git a/libguile/vm-i-system.c b/libguile/vm-i-system.c index 27c6c3374..76ae0691d 100644 --- a/libguile/vm-i-system.c +++ b/libguile/vm-i-system.c @@ -484,12 +484,12 @@ VM_DEFINE_INSTRUCTION (35, br, "br", 3, 0, 0) VM_DEFINE_INSTRUCTION (36, br_if, "br-if", 3, 0, 0) { - BR (scm_is_true_and_not_nil (*sp)); + BR (scm_is_true (*sp)); } VM_DEFINE_INSTRUCTION (37, br_if_not, "br-if-not", 3, 0, 0) { - BR (scm_is_false_or_nil (*sp)); + BR (scm_is_false (*sp)); } VM_DEFINE_INSTRUCTION (38, br_if_eq, "br-if-eq", 3, 0, 0) |