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. Under the X window system, you
101 can quickly check the value using the @c xev command. For example,
102 the return key, the backspace key, and the 0 key on the keypad are
103 represented as @c (Return) , @c (BackSpace) , and @c (KP_0)
104 respectively. If the shift, control, meta, alt, super, and hyper
105 modifiers are used, they are represented by the S- , C- , M- , A- , s-
106 , and H- prefixes respectively in this oreder. Thus, "return with
107 shift with meta with hyper" is @c (S-M-H-Return) . Note that "a with
108 shift" .. "z with shift" are represented simply as A .. Z . Thus "a
109 with shift with meta with hyper" is @c (M-H-A) .
111 @c INTEGER in the definition of @c KEYSEQ must be a valid character
115 MAP-ACTION ::= ACTION
117 ACTION ::= INSERT | DELETE | SELECT | MOVE | MARK
118 | SHOW | HIDE | PUSHBACK | POP | UNDO | UNHANDLE | SHIFT | CALL
119 | SET | IF | COND | '(' MACRO-NAME ')'
121 PREDEFINED-SYMBOL ::=
122 '@0' | '@1' | '@2' | '@3' | '@4'
123 | '@5' | '@6' | '@7' | '@8' | '@9'
124 | '@<' | '@=' | '@>' | '@-' | '@+' | '@[' | '@]'
129 MACRO-LIST ::= '(' 'macro' MACRO * ')'
131 MACRO ::= '(' MACRO-NAME MACRO-ACTION * ')'
133 MACRO-NAME ::= SYMBOL
135 MACRO-ACTION ::= ACTION
138 MODULE-LIST ::= '(' 'module' MODULE * ')'
140 MODULE ::= '(' MODULE-NAME FUNCTION * ')'
142 MODULE-NAME ::= SYMBOL
147 Each @c MODULE declares the name of external module (i.e. dynamic
148 library) and function names exported by the module. If a @c FUNCTION has
149 name "init", it is called with only the default arguments (see the
150 section about @c CALL) when an input context is created for the input
151 method. If a @c FUNCTION has name "fini", it is called with only the
152 default arguments when an input context is destroyed.
155 STATE-LIST ::= '(' 'state' STATE * ')'
157 STATE ::= '(' STATE-NAME [ STATE-TITLE-TEXT ] BRANCH * ')'
159 STATE-NAME ::= SYMBOL
161 STATE-TITLE-TEXT ::= MTEXT
163 BRANCH ::= '(' MAP-NAME BRANCH-ACTION * ')'
164 | '(' nil BRANCH-ACTION * ')'
165 | '(' t BRANCH-ACTION * ')'
168 The optional @c STATE-TITLE-TEXT specifies a title text displayed on
169 the screen when the input method is in this state. If @c
170 STATE-TITLE-TEXT is omitted, @c TITLE-TEXT is used.
172 In the first form of @c BRANCH, @c MAP-NAME must be an item that
173 appears in @c MAP. In this case, if a key sequence matching one of @c
174 KEYSEQs of @c MAP-NAME is typed, @c BRANCH-ACTIONs are executed.
176 In the second form of @c BRANCH, @c BRANCH-ACTIONs are executed if a
177 key sequence that doesn't match any of @c Branch's of the current
180 In the third form of @c BRANCH, @c BRANCH-ACTIONs are executed when
181 shifted to the current state. If the current state is the initial
182 state, @c BRANCH-ACTIONs are executed also when an input context of
183 the input method is created.
186 BRANCH-ACTION ::= ACTION
189 An input method has the following two lists of symbols.
194 A marker is a symbol indicating a character position in the preediting
195 text. The @c MARK action assigns a position to a marker. The
196 position of a marker is referred by the @c MOVE and the @c DELETE actions.
200 A variable is a symbol associated with an integer value. The value of
201 a variable is set by the @c SET action, and is referred by the @c SET,
202 the @c INSERT, and the @c IF actions. All variables are implicitly
207 Each @c PREDEFINED-SYMBOL has a special meaning when used as a marker.
210 <li> @c @@0, @c @@1, @c @@2, @c @@3, @c @@4, @c @@5, @c @@6, @c @@7, @c @@8, @c @@9
212 The 0th, 1st, 2nd, ... 9th position respectively.
214 <li> @c @@<, @c @@=, @c @@>
216 The first, the current, and the last position.
220 The previous and the next position.
224 The previous and the next position where a candidate list changes.
227 Some of the @c PREDEFINED-SYMBOL has a special meaning when used as a candidate
228 index in the @c SELECT action.
232 <li> @c @@<, @c @@=, @c @@>
234 The first, the current, and the last candidate of the current candidate group.
238 The previous candidate. If the current candidate is the first one in
239 the current candidate group, then it means the last candidate in the
240 previous candidate group.
244 The next candidate. If the current candidate is the last one in the
245 current candidate group, then it means the first candidate in the next
250 The candidate in the previous and the next candidate group having the same
251 candidate index as the current one.
254 And, this also has a special meaning.
259 Number of handled keys at that moment.
263 These are for supporting surround text handling.
268 Here, @c N is a positive integer. The value is a character at Nth
269 previous position from the current caret of the surrounding text.
270 When this is used as the argument of @c delete action, it specifies
271 how many preceding characters in the surround text to delete.
275 Here, @c N is a positive integer. The value is a character at Nth
276 next position from the current caret of the surrounding text.
277 When this is used as the argument of @c delete action, it specifies
278 how many following characters in the surround text to delete.
281 The arguments and the behavior of each action are listed below.
284 INSERT ::= '(' 'insert' MTEXT ')'
287 | '(' 'insert' SYMBOL ')'
288 | '(' 'insert' '(' CANDIDATES * ')' ')'
289 | '(' CANDIDATES * ')'
291 CANDIDATES ::= MTEXT | '(' MTEXT * ')'
294 The first and second forms insert @c MTEXT before the current position.
296 The third form inserts the character @c INTEGER before the current
299 The fourth form treats @c SYMBOL as a variable, and inserts its value
300 (if it is a valid character code) before the current position.
302 In the fifth and sixth forms, each @c CANDIDATES represents a
303 candidate group, and each element of @c CANDIDATES represents a
304 candidate, i.e. if @c CANDIDATES is an M-text, the candidates are the
305 characters in the M-text; if @c CANDIDATES is a list of M-texts, the
306 candidates are the M-texts in the list.
308 These forms insert the first candidate before the current position.
309 The inserted string is associated with the list of candidates and
310 the information indicating the currently selected candidate.
312 The marker positions affected by the insertion are automatically relocated.
315 DELETE ::= '(' 'delete' SYMBOL ')'
316 | '(' 'delete' INTEGER ')'
319 The first form treats @c SYMBOL as a marker, and deletes characters
320 between the current position and the marker position.
322 The second form treats @c INTEGER as a character position, and deletes
323 characters between the current position and the character position.
325 The marker positions affected by the deletion are automatically relocated.
328 SELECT ::= '(' 'select' PREDEFINED-SYMBOL ')'
329 | '(' 'select' INTEGER ')'
332 This action first checks if the character just before the current position
333 belongs to a string that is associated with a candidate list. If it is,
334 the action replaces that string with a candidate specified by the
337 The first form treats @c PREDEFINED-SYMBOL as a candidate index (as
338 described above) that specifies a new candidate in the candidate list.
340 The second form treats @c INTEGER as a candidate index that specifies a
341 new candidate in the candidate list.
347 This actions instructs the input method driver to display a candidate
348 list associated with the string before the current position.
354 This action instructs the input method driver to hide the currently
355 displayed candidate list.
358 MOVE ::= '(' 'move' SYMBOL ')'
359 | '(' 'move' INTEGER ')'
362 The first form treats @c SYMBOL as a marker, and makes the marker
363 position be the new current position.
365 The second form treats @c INTEGER as a character position, and makes
366 that position be the new current position.
369 MARK ::= '(' 'mark' SYMBOL ')'
372 This action treats @c SYMBOL as a marker, and sets its position to the
373 current position. @c SYMBOL must not be a @c PREDEFINED-SYMBOL.
376 PUSHBACK :: = '(' 'pushback' INTEGER ')'
377 | '(' 'pushback' KEYSEQ ')'
380 The first form pushes back the latest @c INTEGER number of key events
381 to the event queue if @c INTEGER is positive, and pushes back all key
382 events if @c INTEGER is zero.
384 The second form pushes back keys in @c KEYSEQ to the event queue.
387 POP ::= '(' 'pop' ')'
390 This action pops the first key event that is not yet handled from the
394 UNDO :: = '(' 'undo' [ INTEGER | SYMBOL ] ')'
397 If there's no argument, this action cancels the last two key events
398 (i.e. the one that invoked this command, and the previous one).
400 If there's an integer argument NUM, it must be positive or negative
401 (not zero). If positive, from the NUMth to the last events are
402 canceled. If negative the last (- NUM) events are canceled.
404 If there's a symbol argument, it must be resolved to an integer number
405 and the number is treated as the actual argument as above.
408 UNHANDLE :: = '(unhandle)'
411 This action commit the current preedit and return the last key as
415 SHIFT :: = '(' 'shift' STATE-NAME ')'
418 This action shifts the current state to @c STATE-NAME. @c
419 STATE-NAME must appear in @c STATE-LIST.
422 CALL ::= '(' 'call' MODULE-NAME FUNCTION ARG * ')'
424 ARG ::= INTEGER | SYMBOL | MTEXT | PLIST
427 This action calls the function @c FUNCTION of external module @c
428 MODULE-NAME. @c MODULE-NAME and @c FUNCTION must appear in @c
431 The function is called with an argument of the type (#MPlist *). The
432 key of the first element is #Mt and its value is a pointer to an
433 object of the type #MInputContext. The key of the second element is
434 #Msymbol and its value is the current state name. @c ARGs are used as
435 the value of the third and later elements. Their keys are determined
436 automatically; if an @c ARG is an integer, the corresponding key is
437 #Minteger; if an @c ARG is a symbol, the corresponding key is
440 The function must return NULL or a value of the type (#MPlist *) that
441 represents a list of actions to take.
444 SET ::= '(' CMD SYMBOL1 EXPRESSION ')'
446 CMD ::= 'set' | 'add' | 'sub' | 'mul' | 'div'
448 EXPRESSION ::= INTEGER | SYMBOL2 | '(' OPERAND EXPRESSION * ')'
450 OPERAND ::= '+' | '-' | '*' | '/' | '|' | '&' | '!'
451 | '=' | '<' | '>' | '<=' | '>='
455 This action treats @c SYMBOL1 and @c SYMBOL2 as variables and sets the
456 value of @c SYMBOL1 as below.
458 If @c CMD is 'set', it sets the value of @c SYMBOL1 to the value of @c
461 If @c CMD is 'add', it increments the value of @c SYMBOL1 by the value
464 If @c CMD is 'sub', it decrements the value of @c SYMBOL1 by the value
467 If @c CMD is 'mul', it multiplies the value of @c SYMBOL1 by the value
470 If @c CMD is 'div', it divides the value of @c SYMBOL1 by the value of
474 IF ::= '(' CONDITION ACTION-LIST1 ACTION-LIST2 ')'
476 CONDITION ::= [ '=' | '<' | '>' | '<=' | '>=' ] EXPRESSION1 EXPRESSION2
478 ACTION-LIST1 ::= '(' ACTION * ')'
480 ACTION-LIST2 ::= '(' ACTION * ')'
483 This action performs actions in @c ACTION-LIST1 if @c CONDITION is
484 true, and performs @c ACTION-LIST2 (if any) otherwise.
486 @c SYMBOL1 and @c SYMBOL2 are treated as variables.
489 COND ::= '(' 'cond' [ '(' EXPRESSION ACTION * ') ] * ')'
492 This action performs the first action @c ACTION whose corresponding
493 @c EXPRESSION has nonzero value.
497 @section im-example1 EXAMPLE 1
499 This is a very simple example for inputting Latin characters with
500 diacritical marks (acute and cedilla). For instance, when you type:
502 Comme'die-Franc,aise, chic,,
507 Commédie-Française, chic,
512 \hskip5mm\texttt{\footnotesize Comm\'{e}die-Fran\c{c}aise, chic,}
516 The definition of the input method is very simple as below, and it is
517 quite straight forward to extend it to cover all Latin characters.
521 (title "latin-postfix")
524 ("a'" ?á) ("e'" ?é) ("i'" ?í) ("o'" ?ó) ("u'" ?ú) ("c," ?ç)
525 ("A'" ?Á) ("E'" ?É) ("I'" ?Í) ("O'" ?Ó) ("U'" ?Ú) ("C," ?Ç)
526 ("a''" "a'") ("e''" "e'") ("i''" "i'") ("o''" "o'") ("u''" "u'")
528 ("A''" "A'") ("E''" "E'") ("I''" "I'") ("O''" "O'") ("U''" "U'")
537 \texttt{\footnotesize
538 \hskip2mm(title "latin-postfix")\\
541 \hskip6mm ("a'" ?\'{a}) ("e'" ?\'{e}) ("i'" ?\'{i}) ("o'" ?\'{o})
542 ("u'" ?\'{u}) ("c," ?\c{c})\\
543 \hskip6mm ("A'" ?\'{A}) ("E'" ?\'{E}) ("I'" ?\'{I}) ("O'" ?\'{O})
544 ("U'" ?\'{U}) ("C," ?\c{C})\\
545 \hskip6mm ("a''" "a'") ("e''" "e'") ("i''" "i'") ("o''" "o'") ("u''" "u'")\\
546 \hskip6mm ("c,," "c,")\\
547 \hskip6mm ("A''" "A'") ("E''" "E'") ("I''" "I'") ("O''" "O'") ("U''" "U'")\\
548 \hskip6mm ("C,," "C,")))\\
555 @section im-example2 EXAMPLE 2
557 This example is for inputting Unicode characters by typing C-u
558 (Control-u) followed by four hexadecimal digits. For instance, when
559 you type ("^u" means Control-u):
561 ^u2190^u2191^u2192^u2193
563 you will get this (Unicode arrow symbols):
568 The definition utilizes @c SET and @c IF commands as below:
575 ("0" ?0) ("1" ?1) ... ("9" ?9) ("a" ?A) ("b" ?B) ... ("f" ?F)))
578 (starter (set code 0) (set count 0) (shift unicode)))
584 (mul code 16) (add code this)
587 ((delete @<) (insert code) (shift init))))))
590 @section im-example3 EXAMPLE 3
592 This example is for inputting Chinese characters by typing PinYin key
595 For instance, when you type:
604 The definition utilizes @c CANDIDATE and @c SELECT commands as below.
605 Note that this is just an example, and it ignores such important key
612 ;; The initial character of Pinyin.
614 ("a") ("b") ... ("h") ("j") ... ("t") ("w") ("x") ("y") ("z"))
616 ;; Big table of Pinyin vs the corresponding Chinese characters.
619 ("bei" ("被北备背悲辈杯倍贝碑" ...))
620 ("hao" ("好号毫豪浩耗皓嚎昊郝" ...))
621 ("jing" ("经京精境警竟静惊景敬" ...))
622 ("ni" ("你呢尼泥逆倪匿拟腻妮" ...))
624 ;; Typing 1, 2, ..., 0 selects the 0th, 1st, ..., 9th candidate.
626 ("1" (select 0)) ("2" (select 1)) ... ("9" (select 8)) ("0" (select 9))))
630 ;; When an initial character of Pinyin is typed, re-handle it in
631 ;; "main" state. Anything else is just produced as is.
632 (starter (show) (pushback 1) (shift main)))
635 ;; When a complete Pinyin sequence is typed, shift to "select" state
636 ;; to allow users to select one from the candidates.
637 (pinyin (shift select))
639 ;; When anything else is typed, produce the current candidate (if
640 ;; any), and re-handle the last input in "init" state.
641 (nil (hide) (shift init)))
644 ;; When a number is typed, select the corresponding canidate,
645 ;; produce it, and shift to "init" state.
646 (choose (hide) (shift init))
648 ;; When anything else is typed, produce the current candidate,
649 ;; and re-handle the last input in "init" state.
650 (nil (hide) (shift init))))
656 \fbox{This example is readable only in the documentation of HTML version.}
663 @section im-seealso SEE ALSO
665 @ref mim-list "Input Methods provided by the m17n database",
666 @ref mdbGeneral "mdbGeneral(5)"
670 Copyright (C) 2003, 2004, 2005
671 National Institute of Advanced Industrial Science and Technology (AIST)
672 Registration Number H15PRO112
674 This file is part of the m17n database; a sub-part of the m17n
677 The m17n library is free software; you can redistribute it and/or
678 modify it under the terms of the GNU Lesser General Public License
679 as published by the Free Software Foundation; either version 2.1 of
680 the License, or (at your option) any later version.
682 The m17n library is distributed in the hope that it will be useful,
683 but WITHOUT ANY WARRANTY; without even the implied warranty of
684 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
685 Lesser General Public License for more details.
687 You should have received a copy of the GNU Lesser General Public
688 License along with the m17n library; if not, write to the Free
689 Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
690 Boston, MA 02110-1301, USA.
693 /* Local Variables: */