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 ? DESCRIPTION ? VARIABLE-LIST ? COMMAND-LIST ?
28 TITLE MAP-LIST MACRO-LIST ? MODULE-LIST ? STATE-LIST
30 IM-DECLARATION ::= '(' 'input-method' LANGUAGE NAME ')'
31 DESCRIPTION ::= '(' 'description' [ MTEXT-OR-GETTEXT | nil] ')'
32 VARIABLE-LIST ::= '(' 'variable' VARIABLE-DECLARATION * ')'
33 COMMAND-LIST ::= '(' 'command' COMMAND-DECLARATION * ')'
34 TITLE ::= '(' 'title' TITLE-TEXT ')'
36 VARIABLE-DECLARATION ::=
37 '(' VAR-NAME [ MTEXT-OR-GETTEXT | nil ] VALUE VALUE-CANDIDATE * ')'
39 COMMAND-DECLARATION ::=
40 '(' CMD-NAME [ MTEXT-OR-GETTEXT | nil ] KEYSEQ * ')'
43 [ MTEXT | '(' '_' MTEXT ')']
47 IM-DESCRIPTION ::= MTEXT
49 VAR-DESCRIPTION ::= MTEXT
50 VALUE ::= MTEXT | SYMBOL | INTEGER
51 VALUE-CANDIDATE ::= VALUE | '(' RANGE-FROM RANGE-TO ')'
52 RANGE-FROM ::= INTEGER
55 CMD-DESCRIPTION ::= MTEXT
59 @c IM-DECLARATION specifies the language and name of this input
62 @c DESCRIPTION specifies the description text of this input method by
63 MTEXT-OR-GETTEXT. It it takes the second form, the text is translated
64 according to the current locale by "gettext" (if the translation is
67 @c VARIABLE-DECLARATION declares a variable used in this input method.
68 If a variable must be initialized to the default value, or is to be
69 customized by a user, it must be declared here.
71 @c COMMAND-DECLARATION declares a command used in this input method.
72 If a command must be bound to the default key sequence, or is to be
73 customized by a user, it must be declared here.
75 @c TITLE-TEXT is a text displayed on the screen when this input method
79 MAP-LIST ::= '(' 'map' MAP * ')'
81 MAP ::= '(' MAP-NAME RULE * ')'
85 RULE ::= '(' KEYSEQ MAP-ACTION * ')'
87 KEYSEQ ::= MTEXT | '(' [ SYMBOL | INTEGER ] * ')'
90 @c SYMBOL in the definitions of @c MAP-NAME must not be @c t nor @c
93 @c MTEXT in the definition of @c KEYSEQ consists of characters that
94 can be generated by a keyboard. Therefore @c MTEXT usually contains
95 only ASCII characters. However, if the input method is intended to be
96 used, for instance, with a West European keyboard, @c MTEXT may
97 contain Latin-1 characters.
99 @c SYMBOL in the definition of @c KEYSEQ must be the return value of
100 the minput_event_to_key () function.
102 @c INTEGER in the definition of @c KEYSEQ must be a valid character
106 MAP-ACTION ::= ACTION
108 ACTION ::= INSERT | DELETE | SELECT | MOVE | MARK
109 | SHOW | HIDE | PUSHBACK | UNDO | UNHANDLE | SHIFT | CALL
110 | SET | IF | COND | '(' MACRO-NAME ')'
112 PREDEFINED-SYMBOL ::=
113 '@0' | '@1' | '@2' | '@3' | '@4'
114 | '@5' | '@6' | '@7' | '@8' | '@9'
115 | '@<' | '@=' | '@>' | '@-' | '@+' | '@[' | '@]'
120 MACRO-LIST ::= '(' 'macro' MACRO * ')'
122 MACRO ::= '(' MACRO-NAME MACRO-ACTION * ')'
124 MACRO-NAME ::= SYMBOL
126 MACRO-ACTION ::= ACTION
129 MODULE-LIST ::= '(' 'module' MODULE * ')'
131 MODULE ::= '(' MODULE-NAME FUNCTION * ')'
133 MODULE-NAME ::= SYMBOL
138 Each @c MODULE declares the name of external module (i.e. dynamic
139 library) and function names exported by the module. If a @c FUNCTION has
140 name "init", it is called with only the default arguments (see the
141 section about @c CALL) when an input context is created for the input
142 method. If a @c FUNCTION has name "fini", it is called with only the
143 default arguments when an input context is destroyed.
146 STATE-LIST ::= '(' 'state' STATE * ')'
148 STATE ::= '(' STATE-NAME [ STATE-TITLE-TEXT ] BRANCH * ')'
150 STATE-NAME ::= SYMBOL
152 STATE-TITLE-TEXT ::= MTEXT
154 BRANCH ::= '(' MAP-NAME BRANCH-ACTION * ')'
155 | '(' nil BRANCH-ACTION * ')'
156 | '(' t BRANCH-ACTION * ')'
159 The optional @c STATE-TITLE-TEXT specifies a title text displayed on
160 the screen when the input method is in this state. If @c
161 STATE-TITLE-TEXT is omitted, @c TITLE-TEXT is used.
163 In the first form of @c BRANCH, @c MAP-NAME must be an item that
164 appears in @c MAP. In this case, if a key sequence matching one of @c
165 KEYSEQs of @c MAP-NAME is typed, @c BRANCH-ACTIONs are executed.
167 In the second form of @c BRANCH, @c BRANCH-ACTIONs are executed if a
168 key sequence that doesn't match any of @c Branch's of the current
171 In the third form of @c BRANCH, @c BRANCH-ACTIONs are executed when
172 shifted to the current state. If the current state is the initial
173 state, @c BRANCH-ACTIONs are executed also when an input context of
174 the input method is created.
177 BRANCH-ACTION ::= ACTION
180 An input method has the following two lists of symbols.
185 A marker is a symbol indicating a character position in the preediting
186 text. The @c MARK action assigns a position to a marker. The
187 position of a marker is referred by the @c MOVE and the @c DELETE actions.
191 A variable is a symbol associated with an integer value. The value of
192 a variable is set by the @c SET action, and is referred by the @c SET,
193 the @c INSERT, and the @c IF actions. All variables are implicitly
198 Each @c PREDEFINED-SYMBOL has a special meaning when used as a marker.
201 <li> @c @@0, @c @@1, @c @@2, @c @@3, @c @@4, @c @@5, @c @@6, @c @@7, @c @@8, @c @@9
203 The 0th, 1st, 2nd, ... 9th position respectively.
205 <li> @c @@<, @c @@=, @c @@>
207 The first, the current, and the last position.
211 The previous and the next position.
215 The previous and the next position where a candidate list changes.
218 Some of the @c PREDEFINED-SYMBOL has a special meaning when used as a candidate
219 index in the @c SELECT action.
223 <li> @c @@<, @c @@=, @c @@>
225 The first, the current, and the last candidate of the current candidate group.
229 The previous candidate. If the current candidate is the first one in
230 the current candidate group, then it means the last candidate in the
231 previous candidate group.
235 The next candidate. If the current candidate is the last one in the
236 current candidate group, then it means the first candidate in the next
241 The candidate in the previous and the next candidate group having the same
242 candidate index as the current one.
245 And, this also has a special meaning.
250 Number of handled keys at that moment.
254 These are for supporting surround text handling.
259 Here, @c N is a positive integer. The value is a character at Nth
260 previous position from the current caret of the surrounding text.
261 When this is used as the argument of @c delete action, it specifies
262 how many preceding characters in the surround text to delete.
266 Here, @c N is a positive integer. The value is a character at Nth
267 next position from the current caret of the surrounding text.
268 When this is used as the argument of @c delete action, it specifies
269 how many following characters in the surround text to delete.
272 The arguments and the behavior of each action are listed below.
275 INSERT ::= '(' 'insert' MTEXT ')'
278 | '(' 'insert' SYMBOL ')'
279 | '(' 'insert' '(' CANDIDATES * ')' ')'
280 | '(' CANDIDATES * ')'
282 CANDIDATES ::= MTEXT | '(' MTEXT * ')'
285 The first and second forms insert @c MTEXT before the current position.
287 The third form inserts the character @c INTEGER before the current
290 The fourth form treats @c SYMBOL as a variable, and inserts its value
291 (if it is a valid character code) before the current position.
293 In the fifth and sixth forms, each @c CANDIDATES represents a
294 candidate group, and each element of @c CANDIDATES represents a
295 candidate, i.e. if @c CANDIDATES is an M-text, the candidates are the
296 characters in the M-text; if @c CANDIDATES is a list of M-texts, the
297 candidates are the M-texts in the list.
299 These forms insert the first candidate before the current position.
300 The inserted string is associated with the list of candidates and
301 the information indicating the currently selected candidate.
303 The marker positions affected by the insertion are automatically relocated.
306 DELETE ::= '(' 'delete' SYMBOL ')'
307 | '(' 'delete' INTEGER ')'
310 The first form treats @c SYMBOL as a marker, and deletes characters
311 between the current position and the marker position.
313 The second form treats @c INTEGER as a character position, and deletes
314 characters between the current position and the character position.
316 The marker positions affected by the deletion are automatically relocated.
319 SELECT ::= '(' 'select' PREDEFINED-SYMBOL ')'
320 | '(' 'select' INTEGER ')'
323 This action first checks if the character just before the current position
324 belongs to a string that is associated with a candidate list. If it is,
325 the action replaces that string with a candidate specified by the
328 The first form treats @c PREDEFINED-SYMBOL as a candidate index (as
329 described above) that specifies a new candidate in the candidate list.
331 The second form treats @c INTEGER as a candidate index that specifies a
332 new candidate in the candidate list.
338 This actions instructs the input method driver to display a candidate
339 list associated with the string before the current position.
345 This action instructs the input method driver to hide the currently
346 displayed candidate list.
349 MOVE ::= '(' 'move' SYMBOL ')'
350 | '(' 'move' INTEGER ')'
353 The first form treats @c SYMBOL as a marker, and makes the marker
354 position be the new current position.
356 The second form treats @c INTEGER as a character position, and makes
357 that position be the new current position.
360 MARK ::= '(' 'mark' SYMBOL ')'
363 This action treats @c SYMBOL as a marker, and sets its position to the
364 current position. @c SYMBOL must not be a @c PREDEFINED-SYMBOL.
367 PUSHBACK :: = '(' 'pushback' INTEGER ')'
368 | '(' 'pushback' KEYSEQ ')'
371 The first form pushes back the latest @c INTEGER number of key events
372 to the event queue if @c INTEGER is positive, and pushes back all key
373 events if @c INTEGER is zero.
375 The second form pushes back keys in @c KEYSEQ to the event queue.
378 UNDO :: = '(' 'undo' [ INTEGER | SYMBOL ] ')'
381 If there's no argument, this action cancels the last two key events
382 (i.e. the one that invoked this command, and the previous one).
384 If there's an integer argument NUM, it must be positive or negative
385 (not zero). If positive, from the NUMth to the last events are
386 canceled. If negative the last (- NUM) events are canceled.
388 If there's a symbol argument, it must be resolved to an integer number
389 and the number is treated as the actual argument as above.
392 UNHANDLE :: = '(unhandle)'
395 This action commit the current preedit and return the last key as
399 SHIFT :: = '(' 'shift' STATE-NAME ')'
402 This action shifts the current state to @c STATE-NAME. @c
403 STATE-NAME must appear in @c STATE-LIST.
406 CALL ::= '(' 'call' MODULE-NAME FUNCTION ARG * ')'
408 ARG ::= INTEGER | SYMBOL | MTEXT | PLIST
411 This action calls the function @c FUNCTION of external module @c
412 MODULE-NAME. @c MODULE-NAME and @c FUNCTION must appear in @c
415 The function is called with an argument of the type (#MPlist *). The
416 key of the first element is #Mt and its value is a pointer to an
417 object of the type #MInputContext. The key of the second element is
418 #Msymbol and its value is the current state name. @c ARGs are used as
419 the value of the third and later elements. Their keys are determined
420 automatically; if an @c ARG is an integer, the corresponding key is
421 #Minteger; if an @c ARG is a symbol, the corresponding key is
424 The function must return NULL or a value of the type (#MPlist *) that
425 represents a list of actions to take.
428 SET ::= '(' CMD SYMBOL1 EXPRESSION ')'
430 CMD ::= 'set' | 'add' | 'sub' | 'mul' | 'div'
432 EXPRESSION ::= INTEGER | SYMBOL2 | '(' OPERAND EXPRESSION * ')'
434 OPERAND ::= '+' | '-' | '*' | '/' | '|' | '&' | '!'
435 | '=' | '<' | '>' | '<=' | '>='
439 This action treats @c SYMBOL1 and @c SYMBOL2 as variables and sets the
440 value of @c SYMBOL1 as below.
442 If @c CMD is 'set', it sets the value of @c SYMBOL1 to the value of @c
445 If @c CMD is 'add', it increments the value of @c SYMBOL1 by the value
448 If @c CMD is 'sub', it decrements the value of @c SYMBOL1 by the value
451 If @c CMD is 'mul', it multiplies the value of @c SYMBOL1 by the value
454 If @c CMD is 'div', it divides the value of @c SYMBOL1 by the value of
458 IF ::= '(' CONDITION ACTION-LIST1 ACTION-LIST2 ')'
460 CONDITION ::= [ '=' | '<' | '>' | '<=' | '>=' ] EXPRESSION1 EXPRESSION2
462 ACTION-LIST1 ::= '(' ACTION * ')'
464 ACTION-LIST2 ::= '(' ACTION * ')'
467 This action performs actions in @c ACTION-LIST1 if @c CONDITION is
468 true, and performs @c ACTION-LIST2 (if any) otherwise.
470 @c SYMBOL1 and @c SYMBOL2 are treated as variables.
473 COND ::= '(' 'cond' [ '(' EXPRESSION ACTION * ') ] * ')'
476 This action performs the first action @c ACTION whose corresponding
477 @c EXPRESSION has nonzero value.
481 @section im-example1 EXAMPLE 1
483 This is a very simple example for inputting Latin characters with
484 diacritical marks (acute and cedilla). For instance, when you type:
486 Comme'die-Franc,aise, chic,,
491 Commédie-Française, chic,
496 \hskip5mm\texttt{\footnotesize Comm\'{e}die-Fran\c{c}aise, chic,}
500 The definition of the input method is very simple as below, and it is
501 quite straight forward to extend it to cover all Latin characters.
505 (title "latin-postfix")
508 ("a'" ?á) ("e'" ?é) ("i'" ?í) ("o'" ?ó) ("u'" ?ú) ("c," ?ç)
509 ("A'" ?Á) ("E'" ?É) ("I'" ?Í) ("O'" ?Ó) ("U'" ?Ú) ("C," ?Ç)
510 ("a''" "a'") ("e''" "e'") ("i''" "i'") ("o''" "o'") ("u''" "u'")
512 ("A''" "A'") ("E''" "E'") ("I''" "I'") ("O''" "O'") ("U''" "U'")
521 \texttt{\footnotesize
522 \hskip2mm(title "latin-postfix")\\
525 \hskip6mm ("a'" ?\'{a}) ("e'" ?\'{e}) ("i'" ?\'{i}) ("o'" ?\'{o})
526 ("u'" ?\'{u}) ("c," ?\c{c})\\
527 \hskip6mm ("A'" ?\'{A}) ("E'" ?\'{E}) ("I'" ?\'{I}) ("O'" ?\'{O})
528 ("U'" ?\'{U}) ("C," ?\c{C})\\
529 \hskip6mm ("a''" "a'") ("e''" "e'") ("i''" "i'") ("o''" "o'") ("u''" "u'")\\
530 \hskip6mm ("c,," "c,")\\
531 \hskip6mm ("A''" "A'") ("E''" "E'") ("I''" "I'") ("O''" "O'") ("U''" "U'")\\
532 \hskip6mm ("C,," "C,")))\\
539 @section im-example2 EXAMPLE 2
541 This example is for inputting Unicode characters by typing C-u
542 (Control-u) followed by four hexadecimal digits. For instance, when
543 you type ("^u" means Control-u):
545 ^u2190^u2191^u2192^u2193
547 you will get this (Unicode arrow symbols):
552 The definition utilizes @c SET and @c IF commands as below:
559 ("0" ?0) ("1" ?1) ... ("9" ?9) ("a" ?A) ("b" ?B) ... ("f" ?F)))
562 (starter (set code 0) (set count 0) (shift unicode)))
568 (mul code 16) (add code this)
571 ((delete @<) (insert code) (shift init))))))
574 @section im-example3 EXAMPLE 3
576 This example is for inputting Chinese characters by typing PinYin key
579 For instance, when you type:
588 The definition utilizes @c CANDIDATE and @c SELECT commands as below.
589 Note that this is just an example, and it ignores such important key
596 ;; The initial character of Pinyin.
598 ("a") ("b") ... ("h") ("j") ... ("t") ("w") ("x") ("y") ("z"))
600 ;; Big table of Pinyin vs the corresponding Chinese characters.
603 ("bei" ("被北备背悲辈杯倍贝碑" ...))
604 ("hao" ("好号毫豪浩耗皓嚎昊郝" ...))
605 ("jing" ("经京精境警竟静惊景敬" ...))
606 ("ni" ("你呢尼泥逆倪匿拟腻妮" ...))
608 ;; Typing 1, 2, ..., 0 selects the 0th, 1st, ..., 9th candidate.
610 ("1" (select 0)) ("2" (select 1)) ... ("9" (select 8)) ("0" (select 9))))
614 ;; When an initial character of Pinyin is typed, re-handle it in
615 ;; "main" state. Anything else is just produced as is.
616 (starter (show) (pushback 1) (shift main)))
619 ;; When a complete Pinyin sequence is typed, shift to "select" state
620 ;; to allow users to select one from the candidates.
621 (pinyin (shift select))
623 ;; When anything else is typed, produce the current candidate (if
624 ;; any), and re-handle the last input in "init" state.
625 (nil (hide) (shift init)))
628 ;; When a number is typed, select the corresponding canidate,
629 ;; produce it, and shift to "init" state.
630 (choose (hide) (shift init))
632 ;; When anything else is typed, produce the current candidate,
633 ;; and re-handle the last input in "init" state.
634 (nil (hide) (shift init))))
640 \fbox{This example is readable only in the documentation of HTML version.}
647 @section im-seealso SEE ALSO
649 @ref mim-list "Input Methods provided by the m17n database",
650 @ref mdbGeneral "mdbGeneral(5)"
654 Copyright (C) 2003, 2004, 2005
655 National Institute of Advanced Industrial Science and Technology (AIST)
656 Registration Number H15PRO112
658 This file is part of the m17n database; a sub-part of the m17n
661 The m17n library is free software; you can redistribute it and/or
662 modify it under the terms of the GNU Lesser General Public License
663 as published by the Free Software Foundation; either version 2.1 of
664 the License, or (at your option) any later version.
666 The m17n library is distributed in the hope that it will be useful,
667 but WITHOUT ANY WARRANTY; without even the implied warranty of
668 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
669 Lesser General Public License for more details.
671 You should have received a copy of the GNU Lesser General Public
672 License along with the m17n library; if not, write to the Free
673 Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
677 /* Local Variables: */