From: Chong Yidong Date: Sat, 2 Jan 2010 18:55:19 +0000 (-0500) Subject: Consistently hex notation to represent character codes. X-Git-Tag: emacs-pretest-23.1.92~98 X-Git-Url: http://git.eshelyaron.com/gitweb/?a=commitdiff_plain;h=85eeac935fabe769e3b73d228215005f2a5cece2;p=emacs.git Consistently hex notation to represent character codes. * nonascii.texi (Text Representations, Character Codes) (Converting Representations, Explicit Encoding) (Translation of Characters): Use hex notation consistently. (Character Sets): Fix map-charset-chars doc (Bug#5197). --- diff --git a/doc/lispref/ChangeLog b/doc/lispref/ChangeLog index 0f4abc7a984..419e81904ed 100644 --- a/doc/lispref/ChangeLog +++ b/doc/lispref/ChangeLog @@ -1,3 +1,10 @@ +2010-01-02 Chong Yidong + + * nonascii.texi (Text Representations, Character Codes) + (Converting Representations, Explicit Encoding) + (Translation of Characters): Use hex notation consistently. + (Character Sets): Fix map-charset-chars doc (Bug#5197). + 2010-01-01 Chong Yidong * loading.texi (Where Defined): Make it clearer that these are diff --git a/doc/lispref/nonascii.texi b/doc/lispref/nonascii.texi index d3bbc2c114f..59f790c90da 100644 --- a/doc/lispref/nonascii.texi +++ b/doc/lispref/nonascii.texi @@ -46,12 +46,12 @@ in most any known written language. follows the @dfn{Unicode Standard}. The Unicode Standard assigns a unique number, called a @dfn{codepoint}, to each and every character. The range of codepoints defined by Unicode, or the Unicode -@dfn{codespace}, is @code{0..10FFFF} (in hex), inclusive. Emacs -extends this range with codepoints in the range @code{110000..3FFFFF}, -which it uses for representing characters that are not unified with -Unicode and raw 8-bit bytes that cannot be interpreted as characters -(the latter occupy the range @code{3FFF80..3FFFFF}). Thus, a -character codepoint in Emacs is a 22-bit integer number. +@dfn{codespace}, is @code{0..#x10FFFF} (in hexadecimal notation), +inclusive. Emacs extends this range with codepoints in the range +@code{#x110000..#x3FFFFF}, which it uses for representing characters +that are not unified with Unicode and @dfn{raw 8-bit bytes} that +cannot be interpreted as characters. Thus, a character codepoint in +Emacs is a 22-bit integer number. @cindex internal representation of characters @cindex characters, representation in buffers and strings @@ -189,8 +189,8 @@ of characters as @var{string}. If @var{string} is a multibyte string, it is returned unchanged. The function assumes that @var{string} includes only @acronym{ASCII} characters and raw 8-bit bytes; the latter are converted to their multibyte representation corresponding -to the codepoints in the @code{3FFF80..3FFFFF} area (@pxref{Text -Representations, codepoints}). +to the codepoints @code{#x3FFF80} through @code{#x3FFFFF}, inclusive +(@pxref{Text Representations, codepoints}). @end defun @defun string-to-unibyte string @@ -271,15 +271,19 @@ contains no text properties. The unibyte and multibyte text representations use different character codes. The valid character codes for unibyte representation -range from 0 to 255---the values that can fit in one byte. The valid -character codes for multibyte representation range from 0 to 4194303 -(#x3FFFFF). In this code space, values 0 through 127 are for -@acronym{ASCII} characters, and values 128 through 4194175 (#x3FFF7F) -are for non-@acronym{ASCII} characters. Values 0 through 1114111 -(#10FFFF) correspond to Unicode characters of the same codepoint; -values 1114112 (#110000) through 4194175 (#x3FFF7F) represent -characters that are not unified with Unicode; and values 4194176 -(#x3FFF80) through 4194303 (#x3FFFFF) represent eight-bit raw bytes. +range from 0 to @code{#xFF} (255)---the values that can fit in one +byte. The valid character codes for multibyte representation range +from 0 to @code{#x3FFFFF}. In this code space, values 0 through +@code{#x7F} (127) are for @acronym{ASCII} characters, and values +@code{#x80} (128) through @code{#x3FFF7F} (4194175) are for +non-@acronym{ASCII} characters. + + Emacs character codes are a superset of the Unicode standard. +Values 0 through @code{#x10FFFF} (1114111) correspond to Unicode +characters of the same codepoint; values @code{#x110000} (1114112) +through @code{#x3FFF7F} (4194175) represent characters that are not +unified with Unicode; and values @code{#x3FFF80} (4194176) through +@code{#x3FFFFF} (4194303) represent eight-bit raw bytes. @defun characterp charcode This returns @code{t} if @var{charcode} is a valid character, and @@ -540,7 +544,7 @@ and strings. @cindex @code{eight-bit}, a charset Emacs defines several special character sets. The character set @code{unicode} includes all the characters whose Emacs code points are -in the range @code{0..10FFFF}. The character set @code{emacs} +in the range @code{0..#x10FFFF}. The character set @code{emacs} includes all @acronym{ASCII} and non-@acronym{ASCII} characters. Finally, the @code{eight-bit} charset includes the 8-bit raw bytes; Emacs uses it to represent raw bytes encountered in text. @@ -628,12 +632,12 @@ that fits the second argument of @code{decode-char} above. If The following function comes in handy for applying a certain function to all or part of the characters in a charset: -@defun map-charset-chars function charset &optional arg from to +@defun map-charset-chars function charset &optional arg from-code to-code Call @var{function} for characters in @var{charset}. @var{function} is called with two arguments. The first one is a cons cell @code{(@var{from} . @var{to})}, where @var{from} and @var{to} indicate a range of characters contained in charset. The second -argument is the optional argument @var{arg}. +argument passed to @var{function} is @var{arg}. By default, the range of codepoints passed to @var{function} includes all the characters in @var{charset}, but optional arguments @@ -751,7 +755,7 @@ This variable automatically becomes buffer-local when set. @defun make-translation-table-from-vector vec This function returns a translation table made from @var{vec} that is -an array of 256 elements to map byte values 0 through 255 to +an array of 256 elements to map bytes (values 0 through #xFF) to characters. Elements may be @code{nil} for untranslated bytes. The returned table has a translation table for reverse mapping in the first extra slot, and the value @code{1} in the second extra slot. @@ -1562,10 +1566,10 @@ in this section. text. They logically consist of a series of byte values; that is, a series of @acronym{ASCII} and eight-bit characters. In unibyte buffers and strings, these characters have codes in the range 0 -through 255. In a multibyte buffer or string, eight-bit characters -have character codes higher than 255 (@pxref{Text Representations}), -but Emacs transparently converts them to their single-byte values when -you encode or decode such text. +through #xFF (255). In a multibyte buffer or string, eight-bit +characters have character codes higher than #xFF (@pxref{Text +Representations}), but Emacs transparently converts them to their +single-byte values when you encode or decode such text. The usual way to read a file into a buffer as a sequence of bytes, so you can decode the contents explicitly, is with