+++ /dev/null
-/***@page m17nDatabaseFormat Data Format of the m17n database
-
-This section describes formats of data in the m17n database.
-
-@section dbformat General format
-
-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
-with a semicolon (<tt>;</tt>) and extend to the end of the line.
-
-The key and the value of each property are determined based on the
-type of the element as explained below.
-
-<ul>
-
-<li> INTEGER
-
-An element that matches the regular expression <tt>-?[0-9]+</tt> or
-<tt>0[xX][0-9A-Fa-f]+</tt> represents a property whose key is
-<tt>Minteger</tt>. An element matching the former expression is
-interpreted as an integer in decimal notation, and one matching the
-latter is interpreted as an integer in hexadecimal notation. The
-value of the property is the result of interpretation.
-
-For instance, the element <tt>0xA0</tt> represents a property whose value is
-160 in decimal.
-
-<li> SYMBOL
-
-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>\\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
-as it is. The value of the property is the symbol having the
-resulting string as its name.
-
-For instance, the element <tt>abc\ def</tt> represents a property
-whose value is the symbol having the name "abc def".
-
-<li> M-TEXT
-
-An element that matches the regular expression <tt>"([^"]|\\")*"</tt>
-represents a property whose key is <tt>Mtext</tt>. The backslash escape
-explained above also applies here. Moreover, each part in the
-element matching the regular expression <tt>
-\\[xX][0-9A-Fa-f][0-9A-Fa-f]</tt> is replaced with its hexadecimal
-interpretation.
-
-After having resolved the backslash escapes, the byte sequence between
-the double quotes is interpreted as a UTF-8 sequence and decoded into
-an M-text. This M-text is the value of the property.
-
-<li> PLIST
-
-Zero or more elements surrounded by a pair of parentheses represent a
-property whose key is <tt>Mplist</tt>. Whitespaces before and after a
-parenthesis can be omitted. The value of the property is a plist,
-which is the result of recursive interpretation of the elements
-between the parentheses.
-
-</ul>
-
-EXAMPLE
-
-Here is an example of plist that is written in the expression
-explained above.
-
-@verbatim
-abc 123 (pqr 0xff) "m\"text" (_\\_ ("string" xyz) -456)
-@endverbatim
-
-It represents the following plist:
-
-@verbatim
-(Msymbol:abc,
- Minteger:123,
- Mplist:(Msymbol:pqr,
- Minteger:255),
- Mtext:m"text,
- Mplist:(Msymbol:_\_,
- Mplist:(Mtext:string,
- Msymbol:xyz),
- Minteger:-456))
-@endverbatim
-
-@section fontenc Font Encoding
-
-The m17n library loads information about the encoding of each font
-form the m17n database by the tags \<font, encoding\>. The plist
-format of the data is as follows:
-
-@verbatim
-FONT-ENCODING ::=
- PER-FONT-INFO *
-
-PER-FONT-INFO ::=
- '(' FONT-SPEC ENCODING ')'
-
-FONT-SPEC ::=
- '('
- [ FOUNDRY FAMILY [ WEIGHT [ STYLE [ STRETCH [ ADSTYLE ] ] ] ] ] REGISTRY
- ')'
-@endverbatim
-
-@c FOUNDRY to @c REGISTRY are symbols specifying the corresponding
-XLFD font name fields. Omitted symbols are regarded as @c nil, and
-@c nil means a wild card. For instance, this @c FONT-SPEC:
-
-@verbatim
- (nil alice0\ lao iso8859-1)
-@endverbatim
-
-should be applied to all fonts whose family is "alice0 lao", and
-registry is "iso8859-1".
-
-@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
-(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,
-resize\>. The plist format of the data is as follows:
-
-@verbatim
-FONT-RESIZE ::=
- PER-FONT-INFO *
-
-PER-FONT-INFO ::=
- '(' FONT-SPEC RESIZE-RATIO ')'
-
-FONT-SPEC ::=
- '('
- [ FOUNDRY FAMILY [ WEIGHT [ STYLE [ STRETCH [ ADSTYLE ] ] ] ] ] REGISTRY
- ')'
-@endverbatim
-
-The meanings of @c FOUNDRY to @c REGISTRY are the same as @e Font @e
-Encoding. @c RESIZE-RATIO is an integer number specifying by
-percentage how much the font-size must be adjusted. For instance,
-this @c PER-FONT-INFO:
-
-@verbatim
- ((devanagari-cdac) 150)
-@endverbatim
-
-means that, to use a font of registry "devanagari-cdac" with a
-specific size, we have to open an 1.5 times bigger one.
-
-@section fontset Fontset
-
-The m17n library loads a fontset definition from the m17n database by
-the tags \<fontset, FONTSET-NAME\>. The plist format of the data is
-as follows:
-
-@verbatim
-FONTSET ::=
- PER-SCRIPT * PER-CHARSET * FALLBACK *
-
-PER-SCRIPT ::=
- '(' SCRIPT PER-LANGUAGE + ')'
-
-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 ::=
- '('
- [ FOUNDRY FAMILY [ WEIGHT [ STYLE [ STRETCH [ ADSTYLE ] ] ] ] ] REGISTRY
- ')'
-@endverbatim
-
-@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
-of @ref flt.
-
-For instance, this @c PER_SCRIPT:
-
-@verbatim
-(han
- (ja
- ((jisx0208.1983-0)))
- (zh
- ((gb2312.1980-0)))
- (nil
- ((big5-0))))
-@endverbatim
-
-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
-"han" character does not have @c Mlangauge text property, try all
-three fonts.
-
-@section flt Font Layout Table
-
-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
-follows:
-
-@verbinclude flt.txt
-
-@section im Input Method
-
-@verbinclude im.txt
-
-*/
-
-////
projects / m17n / m17n-docs.git / blobdiff