1 /* Copyright (C) 2003, 2004, 2005
2 National Institute of Advanced Industrial Science and Technology (AIST)
3 Registration Number H15PRO112
4 See the end for copying conditions. */
8 @page mdbIM Input Method
10 @section im-description DESCRIPTION
12 The m17n library provides a driver for input methods that are
13 dynamically loadable from the m17n database (see @ref m17nInputMethod
14 @latexonly (P.\pageref{group__m17nInputMethod}) @endlatexonly).
16 This section describes the data format that defines those input
19 @section im-format SYNTAX and SEMANTICS
21 The following data format defines an input method. The driver loads a
22 definition from a file, a stream, etc. The definition is converted
23 into the form of plist in the driver.
27 IM-DECLARATION ? IM-DESCRIPTION ? TITLE ?
28 VARIABLE-LIST ? COMMAND-LIST ? MODULE-LIST ?
29 MACRO-LIST ? MAP-LIST ? STATE-LIST ?
31 IM-DECLARATION ::= '(' 'input-method' LANGUAGE NAME EXTRA-ID ? VERSION ? ')'
35 VERSION ::= '(' 'version' VERSION-NUMBER ')'
37 IM-DESCRIPTION ::= '(' 'description' DESCRIPTION ')'
38 DESCRIPTION ::= MTEXT-OR-GETTEXT | 'nil'
39 MTEXT-OR-GETTEXT ::= [ MTEXT | '(' '_' MTEXT ')']
41 TITLE ::= '(' 'title' TITLE-TEXT ')'
44 VARIABLE-LIST ::= '(' 'variable' VARIABLE-DECLARATION * ')'
45 VARIABLE-DECLARATION ::= '(' VAR-NAME [ DESCRIPTION VALUE VALUE-CANDIDATE * ]')'
47 VALUE ::= MTEXT | SYMBOL | INTEGER
48 VALUE-CANDIDATE ::= VALUE | '(' RANGE-FROM RANGE-TO ')'
49 RANGE-FROM ::= INTEGER
52 COMMAND-LIST ::= '(' 'command' COMMAND-DECLARATION * ')'
53 COMMAND-DECLARATION ::= '(' CMD-NAME [ DESCRIPTION KEYSEQ * ] ')'
58 @c IM-DECLARATION specifies the language and name of this input
61 When @c LANGUAGE is @c t, the use of the input method is not limited
64 When @c NAME is @c nil, the input method is not standalone, but
65 is expected to be used in other input methods. In such cases,
66 @c EXTRA-ID is required to identify the input method.
68 @c VERSION specifies the required minimum version number of the m17n
69 library. The format is "XX.YY.ZZ" where XX is a major version
70 number, YY is a minor version number, and ZZ is a patch level.
72 @c DESCRIPTION, if not nil, specifies the description text of an input
73 method, a variable or a command. If @c MTEXT-OR-GETTEXT takes the
74 second form, the text is translated according to the current locale by
75 "gettext" (if the translation is provided).
77 @c TITLE-TEXT is a text displayed on the screen when this input method
80 There is one special input method file "global.mim" that declares
81 common variables and commands. The input method driver always loads
82 this file and other input methods can inherit the variables and the
85 @c VARIABLE-DECLARATION declares a variable used in this input method.
86 If a variable must be initialized to the default value, or is to be
87 customized by a user, it must be declared here. The declaration can
88 be used in two ways. One is to introduce a new variable. In that
89 case, @c VALUE must not be omitted. Another is to inherit the variable
90 from what declared in "global.mim", and to give the different default
91 value and/or to make the variable customizable specially for the
92 current input method. In the latter case, @c VALUE can be omitted.
94 @c COMMAND-DECLARATION declares a command used in this input method.
95 If a command must be bound to the default key sequence, or is to be
96 customized by a user, it must be declared here. Like @c
97 VARIABLE-DECLARATION, the declaration can be used in two ways. One is
98 to introduce a new command. In that case, @c KEYSEQ must not be omitted.
99 Another is to inherit the command from what declared in "global.mim",
100 and to give the different key binding and/or to make the command
101 customizable specially for the current input method. In the latter
102 case, @c KEYSEQ can be omitted.
106 MODULE-LIST ::= '(' 'module' MODULE * ')'
108 MODULE ::= '(' MODULE-NAME FUNCTION * ')'
110 MODULE-NAME ::= SYMBOL
115 Each @c MODULE declares the name of an external module (i.e. dynamic
116 library) and function names exported by the module. If a @c FUNCTION has
117 name "init", it is called with only the default arguments (see the
118 section about @c CALL) when an input context is created for the input
119 method. If a @c FUNCTION has name "fini", it is called with only the
120 default arguments when an input context is destroyed.
123 MACRO-LIST ::= MACRO-INCLUSION ? '(' 'macro' MACRO * ')' MACRO-INCLUSION ?
125 MACRO ::= '(' MACRO-NAME MACRO-ACTION * ')'
127 MACRO-NAME ::= SYMBOL
129 MACRO-ACTION ::= ACTION
131 TAGS ::= `(` LANGUAGE NAME EXTRA-ID ? `)`
133 MACRO-INCLUSION ::= '(' 'include' TAGS 'macro' MACRO-NAME ? ')'
137 @c MACRO-INCLUSION includes macros from another input method specified
138 by @c TAGS. When @c MACRO-NAME is not given, all macros from the
139 input method are included.
141 @verbatim MAP-LIST ::= MAP-INCLUSION ? '(' 'map' MAP * ')'
144 MAP ::= '(' MAP-NAME RULE * ')'
148 RULE ::= '(' KEYSEQ MAP-ACTION * ')'
150 KEYSEQ ::= MTEXT | '(' [ SYMBOL | INTEGER ] * ')'
152 MAP-INCLUSION ::= '(' 'include' TAGS 'map' MAP-NAME ? ')'
156 When an input method is never standalone and always included in
157 another method, @c MAP-LIST can be omitted.
159 @c SYMBOL in the definitions of @c MAP-NAME must not be @c t nor @c
162 @c MTEXT in the definition of @c KEYSEQ consists of characters that
163 can be generated by a keyboard. Therefore @c MTEXT usually contains
164 only ASCII characters. However, if the input method is intended to be
165 used, for instance, with a West European keyboard, @c MTEXT may
166 contain Latin-1 characters.
168 @c SYMBOL in the definition of @c KEYSEQ must be the return value of
169 the minput_event_to_key () function. Under the X window system, you
170 can quickly check the value using the @c xev command. For example,
171 the return key, the backspace key, and the 0 key on the keypad are
172 represented as @c (Return) , @c (BackSpace) , and @c (KP_0)
173 respectively. If the shift, control, meta, alt, super, and hyper
174 modifiers are used, they are represented by the S- , C- , M- , A- , s-
175 , and H- prefixes respectively in this order. Thus, "return with
176 shift with meta with hyper" is @c (S-M-H-Return) . Note that "a with
177 shift" .. "z with shift" are represented simply as A .. Z . Thus "a
178 with shift with meta with hyper" is @c (M-H-A) .
180 @c INTEGER in the definition of @c KEYSEQ must be a valid character
183 @c MAP-INCLUSION includes maps from another input method specified by
184 @c TAGS. When @c MAP-NAME is not given, all maps from the input method
189 MAP-ACTION ::= ACTION
191 ACTION ::= INSERT | DELETE | SELECT | MOVE | MARK
192 | SHOW | HIDE | PUSHBACK | POP | UNDO
193 | COMMIT | UNHANDLE | SHIFT | CALL
194 | SET | IF | COND | '(' MACRO-NAME ')'
196 PREDEFINED-SYMBOL ::=
197 '@0' | '@1' | '@2' | '@3' | '@4'
198 | '@5' | '@6' | '@7' | '@8' | '@9'
199 | '@<' | '@=' | '@>' | '@-' | '@+' | '@[' | '@]'
201 | '@-0' | '@-N' | '@+N'
205 STATE-LIST ::= STATE-INCUSION ? '(' 'state' STATE * ')' STATE-INCUSION ?
207 STATE ::= '(' STATE-NAME [ STATE-TITLE-TEXT ] BRANCH * ')'
209 STATE-NAME ::= SYMBOL
211 STATE-TITLE-TEXT ::= MTEXT
213 BRANCH ::= '(' MAP-NAME BRANCH-ACTION * ')'
214 | '(' 'nil' BRANCH-ACTION * ')'
215 | '(' 't' BRANCH-ACTION * ')'
217 STATE-INCLUSION ::= '(' 'include' TAGS 'state' STATE-NAME ? ')'
221 When an input system is never standalone and always included in
222 another system, @c STATE-LIST can be omitted.
224 @c STATE-INCLUSION includes states from another input method specified
225 by @c TAGS. When @c STATE-NAME is not given, all states from the input
228 The optional @c STATE-TITLE-TEXT specifies a title text displayed on
229 the screen when the input method is in this state. If @c
230 STATE-TITLE-TEXT is omitted, @c TITLE-TEXT is used.
232 In the first form of @c BRANCH, @c MAP-NAME must be an item that
233 appears in @c MAP. In this case, if a key sequence matching one of @c
234 KEYSEQs of @c MAP-NAME is typed, @c BRANCH-ACTIONs are executed.
236 In the second form of @c BRANCH, @c BRANCH-ACTIONs are executed if a
237 key sequence that doesn't match any of @c Branch's of the current
240 If there is no @c BRANCH beginning with @c nil and the typed key
241 sequence does not match any of the current @c BRANCHs, the input
242 method transits to the initial state.
244 In the third form of @c BRANCH, @c BRANCH-ACTIONs are executed when
245 shifted to the current state. If the current state is the initial
246 state, @c BRANCH-ACTIONs are executed also when an input context of
247 the input method is created.
250 BRANCH-ACTION ::= ACTION
253 An input method has the following two lists of symbols.
258 A marker is a symbol indicating a character position in the preediting
259 text. The @c MARK action assigns a position to a marker. The
260 position of a marker is referred by the @c MOVE and the @c DELETE actions.
264 A variable is a symbol associated with an integer, a symbol, or an
265 M-text value. The integer value of a variable can be set and referred
266 by the @c SET action. It can be referred by the @c SET, the @c
267 INSERT, the @c SELECT, the @c UNDO, the @c IF, the @c COND actions.
268 The M-text value of a variable can be referred by the @c INSERT
269 action. The symbol value of a variable can not be referred directly,
270 is used the library implicitly (e.g. candidates-charset). All
271 variables are implicitly initialized to the integer value zero.
275 Each @c PREDEFINED-SYMBOL has a special meaning when used as a marker.
278 <li> @c @@0, @c @@1, @c @@2, @c @@3, @c @@4, @c @@5, @c @@6, @c @@7, @c @@8, @c @@9
280 The 0th, 1st, 2nd, ... 9th position respectively.
282 <li> @c @@<, @c @@=, @c @@>
284 The first, the current, and the last position.
288 The previous and the next position.
292 The previous and the next position where a candidate list changes.
295 Some of the @c PREDEFINED-SYMBOL has a special meaning when used as a candidate
296 index in the @c SELECT action.
300 <li> @c @@<, @c @@=, @c @@>
302 The first, the current, and the last candidate of the current candidate group.
306 The previous candidate. If the current candidate is the first one in
307 the current candidate group, then it means the last candidate in the
308 previous candidate group.
312 The next candidate. If the current candidate is the last one in the
313 current candidate group, then it means the first candidate in the next
318 The candidate in the previous and the next candidate group having the same
319 candidate index as the current one.
322 And, this also has a special meaning.
327 Number of handled keys at that moment.
331 These are for supporting surround text handling.
336 -1 if surrounding text is supported, -2 if not.
340 Here, @c N is a positive integer. The value is the Nth previous
341 character in the preedit buffer. If there are only M (M<N) previous
342 characters in it, the value is the (N-M)th previous character from the
343 inputting spot. When this is used as the argument of @c delete
344 action, it specifies the number of characters to be deleted.
348 Here, @c N is a positive integer. The value is the Nth following
349 character in the preedit buffer. If there are only M (M<N) following
350 characters in it, the value is the (N-M)th following character from
351 the inputting spot. When this is used as the argument of @c delete
352 action, it specifies the number of characters to be deleted.
355 The arguments and the behavior of each action are listed below.
358 INSERT ::= '(' 'insert' MTEXT ')'
362 | '(' 'insert' SYMBOL ')'
363 | '(' 'insert' '(' CANDIDATES * ')' ')'
364 | '(' CANDIDATES * ')'
366 CANDIDATES ::= MTEXT | '(' MTEXT * ')'
369 The first and second forms insert @c MTEXT before the current position.
371 The third form inserts the character @c INTEGER before the current
374 The fourth and fith form treats @c SYMBOL as a variable, and inserts
375 its value (if it is a valid character code) before the current
378 In the sixth and seventh forms, each @c CANDIDATES represents a
379 candidate group, and each element of @c CANDIDATES represents a
380 candidate, i.e. if @c CANDIDATES is an M-text, the candidates are the
381 characters in the M-text; if @c CANDIDATES is a list of M-texts, the
382 candidates are the M-texts in the list.
384 These forms insert the first candidate before the current position.
385 The inserted string is associated with the list of candidates and
386 the information indicating the currently selected candidate.
388 The marker positions affected by the insertion are automatically relocated.
391 DELETE ::= '(' 'delete' SYMBOL ')'
392 | '(' 'delete' INTEGER ')'
395 The first form treats @c SYMBOL as a marker, and deletes characters
396 between the current position and the marker position.
398 The second form treats @c INTEGER as a character position, and deletes
399 characters between the current position and the character position.
401 The marker positions affected by the deletion are automatically relocated.
404 SELECT ::= '(' 'select' PREDEFINED-SYMBOL ')'
405 | '(' 'select' INTEGER ')'
406 | '(' 'select' SYMBOL ')'
409 This action first checks if the character just before the current position
410 belongs to a string that is associated with a candidate list. If it is,
411 the action replaces that string with a candidate specified by the
414 The first form treats @c PREDEFINED-SYMBOL as a candidate index (as
415 described above) that specifies a new candidate in the candidate list.
417 The second form treats @c INTEGER as a candidate index that specifies a
418 new candidate in the candidate list.
420 In the third form, @c SYMBOL must have a integer value, and it is treated
421 as a candidate index.
423 @verbatim SHOW ::= '(show)' @endverbatim
425 This actions instructs the input method driver to display a candidate
426 list associated with the string before the current position.
432 This action instructs the input method driver to hide the currently
433 displayed candidate list.
436 MOVE ::= '(' 'move' SYMBOL ')'
437 | '(' 'move' INTEGER ')'
440 The first form treats @c SYMBOL as a marker, and makes the marker
441 position be the new current position.
443 The second form treats @c INTEGER as a character position, and makes
444 that position be the new current position.
447 MARK ::= '(' 'mark' SYMBOL ')'
450 This action treats @c SYMBOL as a marker, and sets its position to the
451 current position. @c SYMBOL must not be a @c PREDEFINED-SYMBOL.
454 PUSHBACK :: = '(' 'pushback' INTEGER ')'
455 | '(' 'pushback' KEYSEQ ')'
458 The first form pushes back the latest @c INTEGER number of key events
459 to the event queue if @c INTEGER is positive, and pushes back all key
460 events if @c INTEGER is zero.
462 The second form pushes back keys in @c KEYSEQ to the event queue.
465 POP ::= '(' 'pop' ')'
468 This action pops the first key event that is not yet handled from the
472 UNDO :: = '(' 'undo' [ INTEGER | SYMBOL ] ')'
475 If there's no argument, this action cancels the last two key events
476 (i.e. the one that invoked this command, and the previous one).
478 If there's an integer argument NUM, it must be positive or negative
479 (not zero). If positive, from the NUMth to the last events are
480 canceled. If negative, the last (- NUM) events are canceled.
482 If there's a symbol argument, it must be resolved to an integer number
483 and the number is treated as the actual argument as above.
486 COMMIT :: = '(commit)'
489 This action commits the current preedit.
492 UNHANDLE :: = '(unhandle)'
495 This action commits the current preedit and returns the last key as
499 SHIFT :: = '(' 'shift' STATE-NAME ')'
502 If @c STATE-NAME is @c t, this action shifts the current state to the
503 previous one, otherwise it shifts to @c STATE-NAME. In the latter
504 case, @c STATE-NAME must appear in @c STATE-LIST.
507 CALL ::= '(' 'call' MODULE-NAME FUNCTION ARG * ')'
509 ARG ::= INTEGER | SYMBOL | MTEXT | PLIST
512 This action calls the function @c FUNCTION of external module @c
513 MODULE-NAME. @c MODULE-NAME and @c FUNCTION must appear in @c
516 The function is called with an argument of the type (#MPlist *). The
517 key of the first element is #Mt and its value is a pointer to an
518 object of the type #MInputContext. The key of the second element is
519 #Msymbol and its value is the current state name. @c ARGs are used as
520 the value of the third and later elements. Their keys are determined
521 automatically; if an @c ARG is an integer, the corresponding key is
522 #Minteger; if an @c ARG is a symbol, the corresponding key is
525 The function must return NULL or a value of the type (#MPlist *) that
526 represents a list of actions to take.
529 SET ::= '(' CMD SYMBOL1 EXPRESSION ')'
531 CMD ::= 'set' | 'add' | 'sub' | 'mul' | 'div'
533 EXPRESSION ::= INTEGER | SYMBOL2 | '(' OPERATOR EXPRESSION * ')'
535 OPERATOR ::= '+' | '-' | '*' | '/' | '|' | '&' | '!'
536 | '=' | '<' | '>' | '<=' | '>='
540 This action treats @c SYMBOL1 and @c SYMBOL2 as variables and sets the
541 value of @c SYMBOL1 as below.
543 If @c CMD is 'set', it sets the value of @c SYMBOL1 to the value of @c
546 If @c CMD is 'add', it increments the value of @c SYMBOL1 by the value
549 If @c CMD is 'sub', it decrements the value of @c SYMBOL1 by the value
552 If @c CMD is 'mul', it multiplies the value of @c SYMBOL1 by the value
555 If @c CMD is 'div', it divides the value of @c SYMBOL1 by the value of
559 IF ::= '(' CONDITION ACTION-LIST1 ACTION-LIST2 ? ')'
561 CONDITION ::= [ '=' | '<' | '>' | '<=' | '>=' ] EXPRESSION1 EXPRESSION2
563 ACTION-LIST1 ::= '(' ACTION * ')'
565 ACTION-LIST2 ::= '(' ACTION * ')'
568 This action performs actions in @c ACTION-LIST1 if @c CONDITION is
569 true, and performs @c ACTION-LIST2 (if any) otherwise.
572 COND ::= '(' 'cond' [ '(' EXPRESSION ACTION * ') ] * ')'
575 This action performs the first action @c ACTION whose corresponding
576 @c EXPRESSION has nonzero value.
580 @section im-example1 EXAMPLE 1
582 This is a very simple example for inputting Latin characters with
583 diacritical marks (acute and cedilla). For instance, when you type:
585 Comme'die-Franc,aise, chic,,
590 Commédie-Française, chic,
595 \hskip5mm\texttt{\footnotesize Comm\'{e}die-Fran\c{c}aise, chic,}
599 The definition of the input method is very simple as below, and it is
600 quite straight forward to extend it to cover all Latin characters.
604 (title "latin-postfix")
607 ("a'" ?á) ("e'" ?é) ("i'" ?í) ("o'" ?ó) ("u'" ?ú) ("c," ?ç)
608 ("A'" ?Á) ("E'" ?É) ("I'" ?Í) ("O'" ?Ó) ("U'" ?Ú) ("C," ?Ç)
609 ("a''" "a'") ("e''" "e'") ("i''" "i'") ("o''" "o'") ("u''" "u'")
611 ("A''" "A'") ("E''" "E'") ("I''" "I'") ("O''" "O'") ("U''" "U'")
620 \texttt{\footnotesize
621 \hskip2mm(title "latin-postfix")\\
624 \hskip6mm ("a'" ?\'{a}) ("e'" ?\'{e}) ("i'" ?\'{i}) ("o'" ?\'{o})
625 ("u'" ?\'{u}) ("c," ?\c{c})\\
626 \hskip6mm ("A'" ?\'{A}) ("E'" ?\'{E}) ("I'" ?\'{I}) ("O'" ?\'{O})
627 ("U'" ?\'{U}) ("C," ?\c{C})\\
628 \hskip6mm ("a''" "a'") ("e''" "e'") ("i''" "i'") ("o''" "o'") ("u''" "u'")\\
629 \hskip6mm ("c,," "c,")\\
630 \hskip6mm ("A''" "A'") ("E''" "E'") ("I''" "I'") ("O''" "O'") ("U''" "U'")\\
631 \hskip6mm ("C,," "C,")))\\
638 @section im-example2 EXAMPLE 2
640 This example is for inputting Unicode characters by typing C-u
641 (Control-u) followed by four hexadecimal digits. For instance, when
642 you type ("^u" means Control-u):
644 ^u2190^u2191^u2192^u2193
646 you will get this (Unicode arrow symbols):
649 $\leftarrow \uparrow \rightarrow \downarrow
658 The definition utilizes @c SET and @c IF commands as below:
665 ("0" ?0) ("1" ?1) ... ("9" ?9) ("a" ?A) ("b" ?B) ... ("f" ?F)))
668 (starter (set code 0) (set count 0) (shift unicode)))
674 (mul code 16) (add code this)
677 ((delete @<) (insert code) (shift init))))))
680 @section im-example3 EXAMPLE 3
682 This example is for inputting Chinese characters by typing PinYin key
685 For instance, when you type:
694 The definition utilizes @c CANDIDATE and @c SELECT commands as below.
695 Note that this is just an example, and it ignores such important key
702 ;; The initial character of Pinyin.
704 ("a") ("b") ... ("h") ("j") ... ("t") ("w") ("x") ("y") ("z"))
706 ;; Big table of Pinyin vs the corresponding Chinese characters.
709 ("bei" ("被北备背悲辈杯倍贝碑" ...))
710 ("hao" ("好号毫豪浩耗皓嚎昊郝" ...))
711 ("jing" ("经京精境警竟静惊景敬" ...))
712 ("ni" ("你呢尼泥逆倪匿拟腻妮" ...))
714 ;; Typing 1, 2, ..., 0 selects the 0th, 1st, ..., 9th candidate.
716 ("1" (select 0)) ("2" (select 1)) ... ("9" (select 8)) ("0" (select 9))))
720 ;; When an initial character of Pinyin is typed, re-handle it in
721 ;; "main" state. Anything else is just produced as is.
722 (starter (show) (pushback 1) (shift main)))
725 ;; When a complete Pinyin sequence is typed, shift to "select" state
726 ;; to allow users to select one from the candidates.
727 (pinyin (shift select))
729 ;; When anything else is typed, produce the current candidate (if
730 ;; any), and re-handle the last input in "init" state.
731 (nil (hide) (shift init)))
734 ;; When a number is typed, select the corresponding canidate,
735 ;; produce it, and shift to "init" state.
736 (choose (hide) (shift init))
738 ;; When anything else is typed, produce the current candidate,
739 ;; and re-handle the last input in "init" state.
740 (nil (hide) (shift init))))
746 \fbox{This example is readable only in the documentation of HTML version.}
753 @section im-seealso SEE ALSO
755 @ref mim-list "Input Methods provided by the m17n database",
756 @ref mdbGeneral "mdbGeneral(5)"
760 Copyright (C) 2003, 2004, 2005
761 National Institute of Advanced Industrial Science and Technology (AIST)
762 Registration Number H15PRO112
764 This file is part of the m17n database; a sub-part of the m17n
767 The m17n library is free software; you can redistribute it and/or
768 modify it under the terms of the GNU Lesser General Public License
769 as published by the Free Software Foundation; either version 2.1 of
770 the License, or (at your option) any later version.
772 The m17n library is distributed in the hope that it will be useful,
773 but WITHOUT ANY WARRANTY; without even the implied warranty of
774 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
775 Lesser General Public License for more details.
777 You should have received a copy of the GNU Lesser General Public
778 License along with the m17n library; if not, write to the Free
779 Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
780 Boston, MA 02110-1301, USA.
783 /* Local Variables: */