*** empty log message ***

[m17n/m17n-docs.git] / data-usr / dbformat.txt

diff --git a/data-usr/dbformat.txt b/data-usr/dbformat.txt
index f94397f..0ad20fb 100644 (file)
--- a/data-usr/dbformat.txt
+++ b/data-usr/dbformat.txt
@@ -1,31 +1,31 @@
-/***@page m17nDatabaseFormat DatabaseFormat
+/***@page m17nDatabaseFormat Data Format of the m17n database

 
 

-This section describes the data formats used in the m17n database.
+This section describes formats of data in the m17n database.

 
 @section dbformat General format
 
 
 @section dbformat General format
 

-The mdatabase_load () function receives a set of tags and returns the
-contents of database in the form of plist.  The keys of the returned
-plist are limited to <tt>Minteger</tt>, <tt>Msymbol</tt>,
-<tt>Mtext</tt>, and <tt>Mplist</tt>.  The type of the value is
-unambiguously determined by the corresponding key.  If the key is
-<tt>Minteger</tt>, the value is an integer.  If the key is
-<tt>Msymbol</tt>, the value is a symbol.  And so on.
-
-A number of expressions are possible to represent a
-plist.  For instance, we can use the form <tt>(K1:V1, K2:V2,
-... ,Kn:Vn)</tt> to represent a plist whose first property key and
-value are K1 and V1, second key and value are K2 and V2, and so on.
-However, we can use a simpler expression here because the types of
-plists used in the m17n database are fairly restricted.
-
-Hereafter, we use an expression, which is similar to
-S-expression, to represent a plist.  (Actually, the default database
-loader of the m17n library is designed to read data files written in
-this expression.)
-
-The expression consists of one or more <i>elements</i>.  Each
-element represents a property, i.e. a single element of a plist.
+The mdatabase_load () function returns the data specified by tags in
+the form of plist if the first tag is not @c Mchartable nor @c
+Mcharset.  The keys of the returned plist are limited to
+<tt>Minteger</tt>, <tt>Msymbol</tt>, <tt>Mtext</tt>, and
+<tt>Mplist</tt>.  The type of the value is unambiguously determined by
+the corresponding key.  If the key is <tt>Minteger</tt>, the value is
+an integer.  If the key is <tt>Msymbol</tt>, the value is a symbol.
+And so on.
+
+A number of expressions are possible to represent a plist.  For
+instance, we can use the form <tt>(K1:V1, K2:V2, ..., Kn:Vn)</tt> to
+represent a plist whose first property key and value are K1 and V1,
+second key and value are K2 and V2, and so on.  However, we can use a
+simpler expression here because the types of plists used in the m17n
+database are fairly restricted.
+
+Hereafter, we use an expression, which is similar to S-expression, to
+represent a plist.  (Actually, the default database loader of the m17n
+library is designed to read data files written in this expression.)
+
+The expression consists of one or more <i>elements</i>.  Each element
+represents a property, i.e. a single element of a plist.

 
 Elements are separated by one or more <i>whitespaces</i>, i.e. a space
 (code 32), a tab (code 9), or a newline (code 10).  Comments begin
 
 Elements are separated by one or more <i>whitespaces</i>, i.e. a space
 (code 32), a tab (code 9), or a newline (code 10).  Comments begin

@@ -52,7 +52,7 @@ For instance, the element <tt>0xA0</tt> represents a property whose value is
 
 An element that matches the regular expression
 <tt>[^-0-9(]([^\\()]|\\.)+</tt> represents a property whose key is
 
 An element that matches the regular expression
 <tt>[^-0-9(]([^\\()]|\\.)+</tt> represents a property whose key is

-<tt> Msymbol</tt>.  In the element, <tt>\\t</tt> , <tt>\\n</tt>,
+<tt> Msymbol</tt>.  In the element, <tt>\\t</tt>, <tt>\\n</tt>,

 <tt>\\r</tt>, and <tt>\\e</tt> are replaced with tab (code 9), newline
 (code 10), carriage return (code 13), and escape (code 27)
 respectively.  Other characters following a backslash is interpreted
 <tt>\\r</tt>, and <tt>\\e</tt> are replaced with tab (code 9), newline
 (code 10), carriage return (code 13), and escape (code 27)
 respectively.  Other characters following a backslash is interpreted

@@ -116,7 +116,7 @@ format of the data is as follows:
 
 @verbatim
 FONT-ENCODING ::=
 
 @verbatim
 FONT-ENCODING ::=

-    '(' PER-FONT-INFO * ')'
+    PER-FONT-INFO *

 
 PER-FONT-INFO ::=
     '(' FONT-SPEC ENCODING ')'
 
 PER-FONT-INFO ::=
     '(' FONT-SPEC ENCODING ')'

@@ -138,14 +138,15 @@ XLFD font name fields.  Omitted symbols are regarded as @c nil, and
 should be applied to all fonts whose family is "alice0 lao", and
 registry is "iso8859-1".
 
 should be applied to all fonts whose family is "alice0 lao", and
 registry is "iso8859-1".
 

-@c ENCODING is a charset symbol.  A font matching @c FONT-SPEC
-supports all characters of the charset, and a character code is mapped
-to the corresponding glyph code of the font by this charset.
+@c ENCODING is a symbol representing a charset.  A font matching @c
+FONT-SPEC supports all characters of the charset, and a character code
+is mapped to the corresponding glyph code of the font by this charset.
+

 
 @section fontsize Font Resizing
 
 In some case, a font contains incorrect information about its size
 
 @section fontsize Font Resizing
 
 In some case, a font contains incorrect information about its size

-(typically in the case of a hacked TrueType font), and results in a
+(typically in the case of a hacked TrueType font), which results in a

 bad text layout when such a font is used in combination with the other
 fonts.  To overcome this problem, the m17n library loads information
 about font-size correction from the m17n database by the tags \<font,
 bad text layout when such a font is used in combination with the other
 fonts.  To overcome this problem, the m17n library loads information
 about font-size correction from the m17n database by the tags \<font,

@@ -153,7 +154,7 @@ resize\>.  The plist format of the data is as follows:
 
 @verbatim
 FONT-RESIZE ::=
 
 @verbatim
 FONT-RESIZE ::=

-    '(' PER-FONT-INFO * ')'
+    PER-FONT-INFO *

 
 PER-FONT-INFO ::=
     '(' FONT-SPEC RESIZE-RATIO ')'
 
 PER-FONT-INFO ::=
     '(' FONT-SPEC RESIZE-RATIO ')'

@@ -184,7 +185,7 @@ as follows:
 
 @verbatim
 FONTSET ::=
 
 @verbatim
 FONTSET ::=

-    '(' PER-SCRIPT + ')'
+    PER-SCRIPT * PER-CHARSET * FALLBACK *

 
 PER-SCRIPT ::=
     '(' SCRIPT PER-LANGUAGE + ')'
 
 PER-SCRIPT ::=
     '(' SCRIPT PER-LANGUAGE + ')'

@@ -192,6 +193,12 @@ PER-SCRIPT ::=
 PER-LANGUAGE ::=
     '(' LANGUAGE FONT-SPEC-ELEMENT + ')'
 
 PER-LANGUAGE ::=
     '(' LANGUAGE FONT-SPEC-ELEMENT + ')'
 

+PER-CHARSET ::=
+    '(' CHARSET FONT-SPEC-ELEMENT + ')'
+
+FALLBACK ::=
+    FONT-SPEC-ELEMENT
+

 FONT-SPEC-ELEMENT ::=
     '(' FONT-SPEC [ FLT-NAME ] ')'
 
 FONT-SPEC-ELEMENT ::=
     '(' FONT-SPEC [ FLT-NAME ] ')'
 

@@ -201,7 +208,7 @@ FONT-SPEC ::=
     ')'
 @endverbatim    
 
     ')'
 @endverbatim    
 

-@c SCRIPT is a symbol of script name (e.g. latin, han), or @c nil.  @c
+@c SCRIPT is a symbol of script name (e.g. latin, han) or @c nil.  @c

 LANGUAGE is a two-letter symbol of language name code defined by ISO
 639 (e.g. ja, zh) or @c nil.  The meanings of @c FOUNDRY to @c
 REGISTRY are the same as @e Font @e Encoding.  @c FLT-NAME is a name
 LANGUAGE is a two-letter symbol of language name code defined by ISO
 639 (e.g. ja, zh) or @c nil.  The meanings of @c FOUNDRY to @c
 REGISTRY are the same as @e Font @e Encoding.  @c FLT-NAME is a name

@@ -223,22 +230,22 @@ instructs the rendering engine to use a font of registry
 "jisx0208.1983-0" for a "han" character that has @c Mlanguage text
 propert "ja" if the character is in the repertories of such fonts.
 Otherwise, try a font of registry "gb2312.1980-0" or "big5-0".  If a
 "jisx0208.1983-0" for a "han" character that has @c Mlanguage text
 propert "ja" if the character is in the repertories of such fonts.
 Otherwise, try a font of registry "gb2312.1980-0" or "big5-0".  If a

-"han" character doesn not have @c Mlangauge text property, try all
+"han" character does not have @c Mlangauge text property, try all

 three fonts.
 
 @section flt Font Layout Table
 
 three fonts.
 
 @section flt Font Layout Table
 

-Usually, the rendering engine converts character codes of a text into
-glyph codes one by one by consulting information about encoding of
-each selected font.  But, for rendering a text that requires
-complicated layouting (e.g. Thai and Indic), such an one to one
-conversion is not sufficient.  In addition, some glyphs must be
-shifted 2-dimensionally on the screen.  For such a case, a font layout
-table (FLT in short) must be used.
-
-A FLT can contain all the information in OpenType Layout Table (CMAP,
-GSUB, and GPOS) in addition to the information about how to extract a
-grapheme cluster and how to re-order characters.
+Usually, the rendering engine converts character codes of into glyph
+codes one by one by consulting information about encoding of each
+selected font.  But, for rendering a text that requires complicated
+layouting (e.g. Thai and Indic), such an one to one conversion is not
+sufficient.  In addition, some glyphs must be shifted 2-dimensionally
+on the screen.  For such a case, a font layout table (FLT in short)
+must be used.
+
+A FLT can contain the information equivarent to OpenType Layout Table
+(CMAP, GSUB, and GPOS) in addition to the information about how to
+extract a grapheme cluster and how to re-order characters.

 
 The m17n library loads a FLT from the m17n database by the tags
 \<font, layouter, FLT-NAME\>.  The plist format of the data is as
 
 The m17n library loads a FLT from the m17n database by the tags
 \<font, layouter, FLT-NAME\>.  The plist format of the data is as