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[bpt/emacs.git] / doc / lispref / nonascii.texi

diff --git a/doc/lispref/nonascii.texi b/doc/lispref/nonascii.texi
index 409ecc7..19c7298 100644 (file)
--- a/doc/lispref/nonascii.texi
+++ b/doc/lispref/nonascii.texi
@@ -1,6 +1,6 @@
 @c -*-texinfo-*-
 @c This is part of the GNU Emacs Lisp Reference Manual.
 @c -*-texinfo-*-
 @c This is part of the GNU Emacs Lisp Reference Manual.

-@c Copyright (C) 1998-1999, 2001-2011  Free Software Foundation, Inc.
+@c Copyright (C) 1998-1999, 2001-2012  Free Software Foundation, Inc.

 @c See the file elisp.texi for copying conditions.
 @setfilename ../../info/characters
 @node Non-ASCII Characters, Searching and Matching, Text, Top
 @c See the file elisp.texi for copying conditions.
 @setfilename ../../info/characters
 @node Non-ASCII Characters, Searching and Matching, Text, Top


@@ -167,7 +167,7 @@ acceptable because the buffer's representation is a choice made by the
 user that cannot be overridden automatically.
 
   Converting unibyte text to multibyte text leaves @acronym{ASCII}
 user that cannot be overridden automatically.
 
   Converting unibyte text to multibyte text leaves @acronym{ASCII}

-characters unchanged, and converts bytes with codes 128 through 159 to
+characters unchanged, and converts bytes with codes 128 through 255 to

 the multibyte representation of raw eight-bit bytes.
 
   Converting multibyte text to unibyte converts all @acronym{ASCII}
 the multibyte representation of raw eight-bit bytes.
 
   Converting multibyte text to unibyte converts all @acronym{ASCII}


@@ -201,7 +201,7 @@ characters.
 @defun byte-to-string byte
 @cindex byte to string
 This function returns a unibyte string containing a single byte of
 @defun byte-to-string byte
 @cindex byte to string
 This function returns a unibyte string containing a single byte of

-character data, @var{character}.  It signals a error if
+character data, @var{character}.  It signals an error if

 @var{character} is not an integer between 0 and 255.
 @end defun
 
 @var{character} is not an integer between 0 and 255.
 @end defun
 


@@ -369,29 +369,44 @@ replacing each @samp{_} character with a dash @samp{-}.  For example,
 @code{canonical-combining-class}.  However, sometimes we shorten the
 names to make their use easier.
 
 @code{canonical-combining-class}.  However, sometimes we shorten the
 names to make their use easier.
 

+@cindex unassigned character codepoints
+  Some codepoints are left @dfn{unassigned} by the
+@acronym{UCD}---they don't correspond to any character.  The Unicode
+Standard defines default values of properties for such codepoints;
+they are mentioned below for each property.
+

   Here is the full list of value types for all the character
 properties that Emacs knows about:
 
 @table @code
 @item name
   Here is the full list of value types for all the character
 properties that Emacs knows about:
 
 @table @code
 @item name

-This property corresponds to the Unicode @code{Name} property.  The
-value is a string consisting of upper-case Latin letters A to Z,
-digits, spaces, and hyphen @samp{-} characters.
+Corresponds to the @code{Name} Unicode property.  The value is a
+string consisting of upper-case Latin letters A to Z, digits, spaces,
+and hyphen @samp{-} characters.  For unassigned codepoints, the value
+is an empty string.

 
 @cindex unicode general category
 @item general-category
 
 @cindex unicode general category
 @item general-category

-This property corresponds to the Unicode @code{General_Category}
-property.  The value is a symbol whose name is a 2-letter abbreviation
-of the character's classification.
+Corresponds to the @code{General_Category} Unicode property.  The
+value is a symbol whose name is a 2-letter abbreviation of the
+character's classification.  For unassigned codepoints, the value
+is @code{Cn}.

 
 @item canonical-combining-class
 
 @item canonical-combining-class

-Corresponds to the Unicode @code{Canonical_Combining_Class} property.
-The value is an integer number.
+Corresponds to the @code{Canonical_Combining_Class} Unicode property.
+The value is an integer number.  For unassigned codepoints, the value
+is zero.

 
 

+@cindex bidirectional class of characters

 @item bidi-class
 Corresponds to the Unicode @code{Bidi_Class} property.  The value is a
 symbol whose name is the Unicode @dfn{directional type} of the
 @item bidi-class
 Corresponds to the Unicode @code{Bidi_Class} property.  The value is a
 symbol whose name is the Unicode @dfn{directional type} of the

-character.
+character.  Emacs uses this property when it reorders bidirectional
+text for display (@pxref{Bidirectional Display}).  For unassigned
+codepoints, the value depends on the code blocks to which the
+codepoint belongs: most unassigned codepoints get the value of
+@code{L} (strong L), but some get values of @code{AL} (Arabic letter)
+or @code{R} (strong R).

 
 @item decomposition
 Corresponds to the Unicode @code{Decomposition_Type} and
 
 @item decomposition
 Corresponds to the Unicode @code{Decomposition_Type} and


@@ -403,19 +418,22 @@ Note that the Unicode spec writes these tag names inside
 brackets; e.g., Unicode specifies @samp{<small>} where Emacs uses
 @samp{small}.
 }; the other elements are characters that give the compatibility
 brackets; e.g., Unicode specifies @samp{<small>} where Emacs uses
 @samp{small}.
 }; the other elements are characters that give the compatibility

-decomposition sequence of this character.
+decomposition sequence of this character.  For unassigned codepoints,
+the value is the character itself.

 
 @item decimal-digit-value
 Corresponds to the Unicode @code{Numeric_Value} property for
 characters whose @code{Numeric_Type} is @samp{Digit}.  The value is an
 
 @item decimal-digit-value
 Corresponds to the Unicode @code{Numeric_Value} property for
 characters whose @code{Numeric_Type} is @samp{Digit}.  The value is an

-integer number.
+integer number.  For unassigned codepoints, the value is @code{nil},
+which means @acronym{NaN}, or ``not-a-number''.

 
 

-@item digit
+@item digit-value

 Corresponds to the Unicode @code{Numeric_Value} property for
 characters whose @code{Numeric_Type} is @samp{Decimal}.  The value is
 an integer number.  Examples of such characters include compatibility
 subscript and superscript digits, for which the value is the
 Corresponds to the Unicode @code{Numeric_Value} property for
 characters whose @code{Numeric_Type} is @samp{Decimal}.  The value is
 an integer number.  Examples of such characters include compatibility
 subscript and superscript digits, for which the value is the

-corresponding number.
+corresponding number.  For unassigned codepoints, the value is
+@code{nil}, which means @acronym{NaN}.

 
 @item numeric-value
 Corresponds to the Unicode @code{Numeric_Value} property for
 
 @item numeric-value
 Corresponds to the Unicode @code{Numeric_Value} property for


@@ -424,33 +442,53 @@ this property is an integer or a floating-point number.  Examples of
 characters that have this property include fractions, subscripts,
 superscripts, Roman numerals, currency numerators, and encircled
 numbers.  For example, the value of this property for the character
 characters that have this property include fractions, subscripts,
 superscripts, Roman numerals, currency numerators, and encircled
 numbers.  For example, the value of this property for the character

-@code{U+2155} (@sc{vulgar fraction one fifth}) is @code{0.2}.
+@code{U+2155} (@sc{vulgar fraction one fifth}) is @code{0.2}.  For
+unassigned codepoints, the value is @code{nil}, which means
+@acronym{NaN}.

 
 

+@cindex mirroring of characters

 @item mirrored
 Corresponds to the Unicode @code{Bidi_Mirrored} property.  The value
 @item mirrored
 Corresponds to the Unicode @code{Bidi_Mirrored} property.  The value

-of this property is a symbol, either @code{Y} or @code{N}.
+of this property is a symbol, either @code{Y} or @code{N}.  For
+unassigned codepoints, the value is @code{N}.
+
+@item mirroring
+Corresponds to the Unicode @code{Bidi_Mirroring_Glyph} property.  The
+value of this property is a character whose glyph represents the
+mirror image of the character's glyph, or @code{nil} if there's no
+defined mirroring glyph.  All the characters whose @code{mirrored}
+property is @code{N} have @code{nil} as their @code{mirroring}
+property; however, some characters whose @code{mirrored} property is
+@code{Y} also have @code{nil} for @code{mirroring}, because no
+appropriate characters exist with mirrored glyphs.  Emacs uses this
+property to display mirror images of characters when appropriate
+(@pxref{Bidirectional Display}).  For unassigned codepoints, the value
+is @code{nil}.

 
 @item old-name
 Corresponds to the Unicode @code{Unicode_1_Name} property.  The value
 
 @item old-name
 Corresponds to the Unicode @code{Unicode_1_Name} property.  The value

-is a string.
+is a string.  For unassigned codepoints, the value is an empty string.

 
 @item iso-10646-comment
 Corresponds to the Unicode @code{ISO_Comment} property.  The value is
 
 @item iso-10646-comment
 Corresponds to the Unicode @code{ISO_Comment} property.  The value is

-a string.
+a string.  For unassigned codepoints, the value is an empty string.

 
 @item uppercase
 Corresponds to the Unicode @code{Simple_Uppercase_Mapping} property.
 
 @item uppercase
 Corresponds to the Unicode @code{Simple_Uppercase_Mapping} property.

-The value of this property is a single character.
+The value of this property is a single character.  For unassigned
+codepoints, the value is @code{nil}, which means the character itself.

 
 @item lowercase
 Corresponds to the Unicode @code{Simple_Lowercase_Mapping} property.
 
 @item lowercase
 Corresponds to the Unicode @code{Simple_Lowercase_Mapping} property.

-The value of this property is a single character.
+The value of this property is a single character.  For unassigned
+codepoints, the value is @code{nil}, which means the character itself.

 
 @item titlecase
 Corresponds to the Unicode @code{Simple_Titlecase_Mapping} property.
 @dfn{Title case} is a special form of a character used when the first
 character of a word needs to be capitalized.  The value of this
 
 @item titlecase
 Corresponds to the Unicode @code{Simple_Titlecase_Mapping} property.
 @dfn{Title case} is a special form of a character used when the first
 character of a word needs to be capitalized.  The value of this

-property is a single character.
+property is a single character.  For unassigned codepoints, the value
+is @code{nil}, which means the character itself.

 @end table
 
 @defun get-char-code-property char propname
 @end table
 
 @defun get-char-code-property char propname


@@ -466,16 +504,19 @@ This function returns the value of @var{char}'s @var{propname} property.
      @result{} Nd
 @end group
 @group
      @result{} Nd
 @end group
 @group

-(get-char-code-property ?\u2084 'digit-value) ; subscript 4
+;; subscript 4
+(get-char-code-property ?\u2084 'digit-value)

      @result{} 4
 @end group
 @group
      @result{} 4
 @end group
 @group

-(get-char-code-property ?\u2155 'numeric-value) ; one fifth
-     @result{} 1/5
+;; one fifth
+(get-char-code-property ?\u2155 'numeric-value)
+     @result{} 0.2

 @end group
 @group
 @end group
 @group

-(get-char-code-property ?\u2163 'numeric-value) ; Roman IV
-     @result{} \4
+;; Roman IV
+(get-char-code-property ?\u2163 'numeric-value)
+     @result{} 4

 @end group
 @end example
 @end defun
 @end group
 @end example
 @end defun


@@ -1449,11 +1490,11 @@ for decoding (in case @var{operation} does decoding), and
 @var{encoding-system} is the coding system for encoding (in case
 @var{operation} does encoding).
 
 @var{encoding-system} is the coding system for encoding (in case
 @var{operation} does encoding).
 

-The argument @var{operation} is a symbol, one of @code{write-region},
-@code{start-process}, @code{call-process}, @code{call-process-region},
-@code{insert-file-contents}, or @code{open-network-stream}.  These are
-the names of the Emacs I/O primitives that can do character code and
-eol conversion.
+The argument @var{operation} is a symbol; it should be one of
+@code{write-region}, @code{start-process}, @code{call-process},
+@code{call-process-region}, @code{insert-file-contents}, or
+@code{open-network-stream}.  These are the names of the Emacs I/O
+primitives that can do character code and eol conversion.

 
 The remaining arguments should be the same arguments that might be given
 to the corresponding I/O primitive.  Depending on the primitive, one
 
 The remaining arguments should be the same arguments that might be given
 to the corresponding I/O primitive.  Depending on the primitive, one


@@ -1539,7 +1580,7 @@ decoding functions (@pxref{Explicit Encoding}).
   Sometimes, you need to prefer several coding systems for some
 operation, rather than fix a single one.  Emacs lets you specify a
 priority order for using coding systems.  This ordering affects the
   Sometimes, you need to prefer several coding systems for some
 operation, rather than fix a single one.  Emacs lets you specify a
 priority order for using coding systems.  This ordering affects the

-sorting of lists of coding sysems returned by functions such as
+sorting of lists of coding systems returned by functions such as

 @code{find-coding-systems-region} (@pxref{Lisp and Coding Systems}).
 
 @defun coding-system-priority-list &optional highestp
 @code{find-coding-systems-region} (@pxref{Lisp and Coding Systems}).
 
 @defun coding-system-priority-list &optional highestp