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-rw-r--r--doc/ref/api-data.texi80
1 files changed, 49 insertions, 31 deletions
diff --git a/doc/ref/api-data.texi b/doc/ref/api-data.texi
index 9bb674a96..ac778b9de 100644
--- a/doc/ref/api-data.texi
+++ b/doc/ref/api-data.texi
@@ -1686,19 +1686,15 @@ starts from 0 for the least significant bit.
@end lisp
@end deffn
-@deffn {Scheme Procedure} ash n cnt
-@deffnx {C Function} scm_ash (n, cnt)
-Return @var{n} shifted left by @var{cnt} bits, or shifted right if
-@var{cnt} is negative. This is an ``arithmetic'' shift.
+@deffn {Scheme Procedure} ash n count
+@deffnx {C Function} scm_ash (n, count)
+Return @math{floor(n * 2^count)}.
+@var{n} and @var{count} must be exact integers.
-This is effectively a multiplication by @m{2^{cnt}, 2^@var{cnt}}, and
-when @var{cnt} is negative it's a division, rounded towards negative
-infinity. (Note that this is not the same rounding as @code{quotient}
-does.)
-
-With @var{n} viewed as an infinite precision twos complement,
-@code{ash} means a left shift introducing zero bits, or a right shift
-dropping bits.
+With @var{n} viewed as an infinite-precision twos-complement
+integer, @code{ash} means a left shift introducing zero bits
+when @var{count} is positive, or a right shift dropping bits
+when @var{count} is negative. This is an ``arithmetic'' shift.
@lisp
(number->string (ash #b1 3) 2) @result{} "1000"
@@ -1709,6 +1705,28 @@ dropping bits.
@end lisp
@end deffn
+@deffn {Scheme Procedure} round-ash n count
+@deffnx {C Function} scm_round_ash (n, count)
+Return @math{round(n * 2^count)}.
+@var{n} and @var{count} must be exact integers.
+
+With @var{n} viewed as an infinite-precision twos-complement
+integer, @code{round-ash} means a left shift introducing zero
+bits when @var{count} is positive, or a right shift rounding
+to the nearest integer (with ties going to the nearest even
+integer) when @var{count} is negative. This is a rounded
+``arithmetic'' shift.
+
+@lisp
+(number->string (round-ash #b1 3) 2) @result{} \"1000\"
+(number->string (round-ash #b1010 -1) 2) @result{} \"101\"
+(number->string (round-ash #b1010 -2) 2) @result{} \"10\"
+(number->string (round-ash #b1011 -2) 2) @result{} \"11\"
+(number->string (round-ash #b1101 -2) 2) @result{} \"11\"
+(number->string (round-ash #b1110 -2) 2) @result{} \"100\"
+@end lisp
+@end deffn
+
@deffn {Scheme Procedure} logcount n
@deffnx {C Function} scm_logcount (n)
Return the number of bits in integer @var{n}. If @var{n} is
@@ -2049,7 +2067,7 @@ number of one to eight digits.
@rnindex char?
@deffn {Scheme Procedure} char? x
@deffnx {C Function} scm_char_p (x)
-Return @code{#t} iff @var{x} is a character, else @code{#f}.
+Return @code{#t} if @var{x} is a character, else @code{#f}.
@end deffn
Fundamentally, the character comparison operations below are
@@ -2057,31 +2075,31 @@ numeric comparisons of the character's code points.
@rnindex char=?
@deffn {Scheme Procedure} char=? x y
-Return @code{#t} iff code point of @var{x} is equal to the code point
+Return @code{#t} if code point of @var{x} is equal to the code point
of @var{y}, else @code{#f}.
@end deffn
@rnindex char<?
@deffn {Scheme Procedure} char<? x y
-Return @code{#t} iff the code point of @var{x} is less than the code
+Return @code{#t} if the code point of @var{x} is less than the code
point of @var{y}, else @code{#f}.
@end deffn
@rnindex char<=?
@deffn {Scheme Procedure} char<=? x y
-Return @code{#t} iff the code point of @var{x} is less than or equal
+Return @code{#t} if the code point of @var{x} is less than or equal
to the code point of @var{y}, else @code{#f}.
@end deffn
@rnindex char>?
@deffn {Scheme Procedure} char>? x y
-Return @code{#t} iff the code point of @var{x} is greater than the
+Return @code{#t} if the code point of @var{x} is greater than the
code point of @var{y}, else @code{#f}.
@end deffn
@rnindex char>=?
@deffn {Scheme Procedure} char>=? x y
-Return @code{#t} iff the code point of @var{x} is greater than or
+Return @code{#t} if the code point of @var{x} is greater than or
equal to the code point of @var{y}, else @code{#f}.
@end deffn
@@ -2099,32 +2117,32 @@ it cannot cover all cases for all languages.
@rnindex char-ci=?
@deffn {Scheme Procedure} char-ci=? x y
-Return @code{#t} iff the case-folded code point of @var{x} is the same
+Return @code{#t} if the case-folded code point of @var{x} is the same
as the case-folded code point of @var{y}, else @code{#f}.
@end deffn
@rnindex char-ci<?
@deffn {Scheme Procedure} char-ci<? x y
-Return @code{#t} iff the case-folded code point of @var{x} is less
+Return @code{#t} if the case-folded code point of @var{x} is less
than the case-folded code point of @var{y}, else @code{#f}.
@end deffn
@rnindex char-ci<=?
@deffn {Scheme Procedure} char-ci<=? x y
-Return @code{#t} iff the case-folded code point of @var{x} is less
+Return @code{#t} if the case-folded code point of @var{x} is less
than or equal to the case-folded code point of @var{y}, else
@code{#f}.
@end deffn
@rnindex char-ci>?
@deffn {Scheme Procedure} char-ci>? x y
-Return @code{#t} iff the case-folded code point of @var{x} is greater
+Return @code{#t} if the case-folded code point of @var{x} is greater
than the case-folded code point of @var{y}, else @code{#f}.
@end deffn
@rnindex char-ci>=?
@deffn {Scheme Procedure} char-ci>=? x y
-Return @code{#t} iff the case-folded code point of @var{x} is greater
+Return @code{#t} if the case-folded code point of @var{x} is greater
than or equal to the case-folded code point of @var{y}, else
@code{#f}.
@end deffn
@@ -2132,36 +2150,36 @@ than or equal to the case-folded code point of @var{y}, else
@rnindex char-alphabetic?
@deffn {Scheme Procedure} char-alphabetic? chr
@deffnx {C Function} scm_char_alphabetic_p (chr)
-Return @code{#t} iff @var{chr} is alphabetic, else @code{#f}.
+Return @code{#t} if @var{chr} is alphabetic, else @code{#f}.
@end deffn
@rnindex char-numeric?
@deffn {Scheme Procedure} char-numeric? chr
@deffnx {C Function} scm_char_numeric_p (chr)
-Return @code{#t} iff @var{chr} is numeric, else @code{#f}.
+Return @code{#t} if @var{chr} is numeric, else @code{#f}.
@end deffn
@rnindex char-whitespace?
@deffn {Scheme Procedure} char-whitespace? chr
@deffnx {C Function} scm_char_whitespace_p (chr)
-Return @code{#t} iff @var{chr} is whitespace, else @code{#f}.
+Return @code{#t} if @var{chr} is whitespace, else @code{#f}.
@end deffn
@rnindex char-upper-case?
@deffn {Scheme Procedure} char-upper-case? chr
@deffnx {C Function} scm_char_upper_case_p (chr)
-Return @code{#t} iff @var{chr} is uppercase, else @code{#f}.
+Return @code{#t} if @var{chr} is uppercase, else @code{#f}.
@end deffn
@rnindex char-lower-case?
@deffn {Scheme Procedure} char-lower-case? chr
@deffnx {C Function} scm_char_lower_case_p (chr)
-Return @code{#t} iff @var{chr} is lowercase, else @code{#f}.
+Return @code{#t} if @var{chr} is lowercase, else @code{#f}.
@end deffn
@deffn {Scheme Procedure} char-is-both? chr
@deffnx {C Function} scm_char_is_both_p (chr)
-Return @code{#t} iff @var{chr} is either uppercase or lowercase, else
+Return @code{#t} if @var{chr} is either uppercase or lowercase, else
@code{#f}.
@end deffn
@@ -2583,8 +2601,8 @@ string is not defined.
@deffn {Scheme Procedure} char-set-contains? cs ch
@deffnx {C Function} scm_char_set_contains_p (cs, ch)
-Return @code{#t} iff the character @var{ch} is contained in the
-character set @var{cs}.
+Return @code{#t} if the character @var{ch} is contained in the
+character set @var{cs}, or @code{#f} otherwise.
@end deffn
@deffn {Scheme Procedure} char-set-every pred cs