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(Booleans): Added reference entries for scm_is_true, scm_is_false,

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scm_is_bool, scm_from_bool, and scm_to_bool.
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Marius Vollmer 2004-07-05 17:37:41 +00:00
parent 800570a6c7
commit 103f4adfbf
1 changed files with 38 additions and 19 deletions
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57
doc/ref/scheme-data.texi
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@ -108,41 +108,60 @@ In C, the two Scheme boolean values are available as the two constants
@code{SCM_BOOL_T} for @code{#t} and @code{SCM_BOOL_F} for @code{#f}.
Care must be taken with the false value @code{SCM_BOOL_F}: it is not
false when used in C conditionals. In order to test for it, use
@code{SCM_FALSEP} or @code{SCM_NFALSEP}.
@code{scm_is_false} or @code{scm_is_true}.
@rnindex not
@deffn {Scheme Procedure} not x
@deffnx {C Function} scm_not (x)
Return @code{#t} iff @var{x} is @code{#f}, else return @code{#f}.
Return @code{#t} if @var{x} is @code{#f}, else return @code{#f}.
@end deffn
@rnindex boolean?
@deffn {Scheme Procedure} boolean? obj
@deffnx {C Function} scm_boolean_p (obj)
Return @code{#t} iff @var{obj} is either @code{#t} or @code{#f}.
Return @code{#t} if @var{obj} is either @code{#t} or @code{#f}, else
return @code{#f}.
@end deffn
@rnindex SCM_BOOL_T
@deffn {C Macro} SCM_BOOL_T
Represents a value that is true in the Scheme sense.
@end deffn
@deftypevr {C Macro} SCM SCM_BOOL_T
The @code{SCM} representation of the Scheme object @code{#t}.
@end deftypevr
@rnindex SCM_BOOL_T
@deffn {C Macro} SCM_BOOL_F
Represents a value that is false in the Scheme sense.
@end deffn
@deftypevr {C Macro} SCM SCM_BOOL_F
The @code{SCM} representation of the Scheme object @code{#f}.
@end deftypevr
@rnindex SCM_FALSEP
@deffn {C Macro} SCM_FALSEP (SCM obj)
Return true in the C sense when @var{obj} is false in the Scheme
sense; return false in the C sense otherwise.
@end deffn
@rnindex scm_is_true
@deftypefn {C Macro} int scm_is_true (SCM obj)
Return @code{0} if @var{obj} is @code{#f}, else return @code{1}.
@end deftypefn
@rnindex SCM_NFALSEP
@deffn {C Macro} SCM_NFALSEP (SCM obj)
Return true in the C sense when @var{obj} is true in the Scheme
sense; return false in the C sense otherwise.
@end deffn
@rnindex scm_is_false
@deftypefn {C Macro} int scm_is_false (SCM obj)
Return @code{1} if @var{obj} is @code{#f}, else return @code{0}.
@end deftypefn
@rnindex scm_is_bool
@deftypefn {C Macro} scm_is_bool (SCM obj)
Return @code{1} if @var{obj} is either @code{#t} or @code{#f}, else
return @code{0}.
@end deftypefn
@rnindex scm_from_bool
@deftypefn {C Macro} SCM scm_from_bool (int val)
Return @code{#f} if @var{val} is @code{0}, else return @code{#t}.
@end deftypefn
@rnindex scm_to_bool
@deftypefn {C Macro} int scm_to_bool (SCM val)
Return @code{1} if @var{val} is @code{SCM_BOOL_T}, return @code{0}
when @var{val} is @code{SCM_BOOL_F}, else signal a `wrong type' error.
You should probably use @code{scm_is_true} instead of this function
when you just want to test a @code{SCM} value for trueness.
@end deftypefn
@node Numbers
@subsection Numerical data types