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1 @c -*-texinfo-*-
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2 @c This is part of the XEmacs Lisp Reference Manual.
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3 @c Copyright (C) 1996 Ben Wing.
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4 @c See the file lispref.texi for copying conditions.
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5 @setfilename ../../info/internationalization.info
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6 @node MULE, Tips, Internationalization, top
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7 @chapter MULE
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8
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9 @dfn{MULE} is the name originally given to the version of GNU Emacs
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10 extended for multi-lingual (and in particular Asian-language) support.
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11 ``MULE'' is short for ``MUlti-Lingual Emacs''. It was originally called
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12 Nemacs (``Nihon Emacs'' where ``Nihon'' is the Japanese word for
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13 ``Japan''), when it only provided support for Japanese. XEmacs
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14 refers to its multi-lingual support as @dfn{MULE support} since it
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15 is based on @dfn{MULE}.
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16
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17 @menu
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18 * Internationalization Terminology::
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19 Definition of various internationalization terms.
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20 * Charsets:: Sets of related characters.
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21 * MULE Characters:: Working with characters in XEmacs/MULE.
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22 * Composite Characters:: Making new characters by overstriking other ones.
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23 * ISO 2022:: An international standard for charsets and encodings.
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24 * Coding Systems:: Ways of representing a string of chars using integers.
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25 * CCL:: A special language for writing fast converters.
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26 * Category Tables:: Subdividing charsets into groups.
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27 @end menu
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28
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29 @node Internationalization Terminology
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30 @section Internationalization Terminology
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31
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32 In internationalization terminology, a string of text is divided up
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33 into @dfn{characters}, which are the printable units that make up the
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34 text. A single character is (for example) a capital @samp{A}, the
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35 number @samp{2}, a Katakana character, a Kanji ideograph (an
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36 @dfn{ideograph} is a ``picture'' character, such as is used in Japanese
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37 Kanji, Chinese Hanzi, and Korean Hangul; typically there are thousands
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38 of such ideographs in each language), etc. The basic property of a
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39 character is its shape. Note that the same character may be drawn by
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40 two different people (or in two different fonts) in slightly different
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41 ways, although the basic shape will be the same.
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42
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43 In some cases, the differences will be significant enough that it is
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44 actually possible to identify two or more distinct shapes that both
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45 represent the same character. For example, the lowercase letters
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46 @samp{a} and @samp{g} each have two distinct possible shapes -- the
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47 @samp{a} can optionally have a curved tail projecting off the top, and
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48 the @samp{g} can be formed either of two loops, or of one loop and a
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49 tail hanging off the bottom. Such distinct possible shapes of a
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50 character are called @dfn{glyphs}. The important characteristic of two
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51 glyphs making up the same character is that the choice between one or
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52 the other is purely stylistic and has no linguistic effect on a word
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53 (this is the reason why a capital @samp{A} and lowercase @samp{a}
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54 are different characters rather than different glyphs -- e.g.
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55 @samp{Aspen} is a city while @samp{aspen} is a kind of tree).
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56
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57 Note that @dfn{character} and @dfn{glyph} are used differently
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58 here than elsewhere in XEmacs.
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59
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60 A @dfn{character set} is simply a set of related characters. ASCII,
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61 for example, is a set of 94 characters (or 128, if you count
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62 non-printing characters). Other character sets are ISO8859-1 (ASCII
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63 plus various accented characters and other international symbols),
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64 JISX0201 (ASCII, more or less, plus half-width Katakana), JISX0208
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65 (Japanese Kanji), JISX0212 (a second set of less-used Japanese Kanji),
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66 GB2312 (Mainland Chinese Hanzi), etc.
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67
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68 Every character set has one or more @dfn{orderings}, which can be
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69 viewed as a way of assigning a number (or set of numbers) to each
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70 character in the set. For most character sets, there is a standard
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71 ordering, and in fact all of the character sets mentioned above define a
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72 particular ordering. ASCII, for example, places letters in their
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73 ``natural'' order, puts uppercase letters before lowercase letters,
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74 numbers before letters, etc. Note that for many of the Asian character
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75 sets, there is no natural ordering of the characters. The actual
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76 orderings are based on one or more salient characteristic, of which
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77 there are many to choose from -- e.g. number of strokes, common
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78 radicals, phonetic ordering, etc.
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79
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80 The set of numbers assigned to any particular character are called
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81 the character's @dfn{position codes}. The number of position codes
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82 required to index a particular character in a character set is called
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83 the @dfn{dimension} of the character set. ASCII, being a relatively
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84 small character set, is of dimension one, and each character in the
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85 set is indexed using a single position code, in the range 0 through
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86 127 (if non-printing characters are included) or 33 through 126
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87 (if only the printing characters are considered). JISX0208, i.e.
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88 Japanese Kanji, has thousands of characters, and is of dimension two --
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89 every character is indexed by two position codes, each in the range
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90 33 through 126. (Note that the choice of the range here is somewhat
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91 arbitrary. Although a character set such as JISX0208 defines an
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92 @emph{ordering} of all its characters, it does not define the actual
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93 mapping between numbers and characters. You could just as easily
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94 index the characters in JISX0208 using numbers in the range 0 through
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95 93, 1 through 94, 2 through 95, etc. The reason for the actual range
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96 chosen is so that the position codes match up with the actual values
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97 used in the common encodings.)
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98
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99 An @dfn{encoding} is a way of numerically representing characters from
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100 one or more character sets into a stream of like-sized numerical values
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101 called @dfn{words}; typically these are 8-bit, 16-bit, or 32-bit
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102 quantities. If an encoding encompasses only one character set, then the
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103 position codes for the characters in that character set could be used
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104 directly. (This is the case with ASCII, and as a result, most people do
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105 not understand the difference between a character set and an encoding.)
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106 This is not possible, however, if more than one character set is to be
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107 used in the encoding. For example, printed Japanese text typically
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108 requires characters from multiple character sets -- ASCII, JISX0208, and
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109 JISX0212, to be specific. Each of these is indexed using one or more
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110 position codes in the range 33 through 126, so the position codes could
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111 not be used directly or there would be no way to tell which character
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112 was meant. Different Japanese encodings handle this differently -- JIS
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113 uses special escape characters to denote different character sets; EUC
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114 sets the high bit of the position codes for JISX0208 and JISX0212, and
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115 puts a special extra byte before each JISX0212 character; etc. (JIS,
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116 EUC, and most of the other encodings you will encounter are 7-bit or
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117 8-bit encodings. There is one common 16-bit encoding, which is Unicode;
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118 this strives to represent all the world's characters in a single large
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119 character set. 32-bit encodings are generally used internally in
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120 programs to simplify the code that manipulates them; however, they are
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121 not much used externally because they are not very space-efficient.)
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122
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123 Encodings are classified as either @dfn{modal} or @dfn{non-modal}. In
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124 a @dfn{modal encoding}, there are multiple states that the encoding can be in,
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125 and the interpretation of the values in the stream depends on the
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126 current global state of the encoding. Special values in the encoding,
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127 called @dfn{escape sequences}, are used to change the global state.
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128 JIS, for example, is a modal encoding. The bytes @samp{ESC $ B}
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129 indicate that, from then on, bytes are to be interpreted as position
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130 codes for JISX0208, rather than as ASCII. This effect is cancelled
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131 using the bytes @samp{ESC ( B}, which mean ``switch from whatever the
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132 current state is to ASCII''. To switch to JISX0212, the escape sequence
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133 @samp{ESC $ ( D}. (Note that here, as is common, the escape sequences do
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134 in fact begin with @samp{ESC}. This is not necessarily the case,
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135 however.)
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136
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137 A @dfn{non-modal encoding} has no global state that extends past the
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138 character currently being interpreted. EUC, for example, is a
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139 non-modal encoding. Characters in JISX0208 are encoded by setting
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140 the high bit of the position codes, and characters in JISX0212 are
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141 encoded by doing the same but also prefixing the character with the
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142 byte 0x8F.
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143
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144 The advantage of a modal encoding is that it is generally more
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145 space-efficient, and is easily extendable because there are essentially
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146 an arbitrary number of escape sequences that can be created. The
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147 disadvantage, however, is that it is much more difficult to work with
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148 if it is not being processed in a sequential manner. In the non-modal
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149 EUC encoding, for example, the byte 0x41 always refers to the letter
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150 @samp{A}; whereas in JIS, it could either be the letter @samp{A}, or
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151 one of the two position codes in a JISX0208 character, or one of the
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152 two position codes in a JISX0212 character. Determining exactly which
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153 one is meant could be difficult and time-consuming if the previous
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154 bytes in the string have not already been processed.
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155
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156 Non-modal encodings are further divided into @dfn{fixed-width} and
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157 @dfn{variable-width} formats. A fixed-width encoding always uses
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158 the same number of words per character, whereas a variable-width
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159 encoding does not. EUC is a good example of a variable-width
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160 encoding: one to three bytes are used per character, depending on
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161 the character set. 16-bit and 32-bit encodings are nearly always
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162 fixed-width, and this is in fact one of the main reasons for using
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163 an encoding with a larger word size. The advantages of fixed-width
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164 encodings should be obvious. The advantages of variable-width
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165 encodings are that they are generally more space-efficient and allow
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166 for compatibility with existing 8-bit encodings such as ASCII.
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167
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168 Note that the bytes in an 8-bit encoding are often referred to
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169 as @dfn{octets} rather than simply as bytes. This terminology
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170 dates back to the days before 8-bit bytes were universal, when
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171 some computers had 9-bit bytes, others had 10-bit bytes, etc.
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172
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173 @node Charsets
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174 @section Charsets
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175
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176 A @dfn{charset} in MULE is an object that encapsulates a
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177 particular character set as well as an ordering of those characters.
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178 Charsets are permanent objects and are named using symbols, like
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179 faces.
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180
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181 @defun charsetp object
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182 This function returns non-@code{nil} if @var{object} is a charset.
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183 @end defun
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184
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185 @menu
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186 * Charset Properties:: Properties of a charset.
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187 * Basic Charset Functions:: Functions for working with charsets.
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188 * Charset Property Functions:: Functions for accessing charset properties.
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189 * Predefined Charsets:: Predefined charset objects.
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190 @end menu
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191
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192 @node Charset Properties
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193 @subsection Charset Properties
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194
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195 Charsets have the following properties:
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196
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197 @table @code
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198 @item name
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199 A symbol naming the charset. Every charset must have a different name;
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200 this allows a charset to be referred to using its name rather than
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201 the actual charset object.
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202 @item doc-string
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203 A documentation string describing the charset.
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204 @item registry
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205 A regular expression matching the font registry field for this character
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206 set. For example, both the @code{ascii} and @code{latin-iso8859-1}
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207 charsets use the registry @code{"ISO8859-1"}. This field is used to
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208 choose an appropriate font when the user gives a general font
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209 specification such as @samp{-*-courier-medium-r-*-140-*}, i.e. a
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210 14-point upright medium-weight Courier font.
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211 @item dimension
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212 Number of position codes used to index a character in the character set.
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213 XEmacs/MULE can only handle character sets of dimension 1 or 2.
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214 This property defaults to 1.
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215 @item chars
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216 Number of characters in each dimension. In XEmacs/MULE, the only
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217 allowed values are 94 or 96. (There are a couple of pre-defined
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218 character sets, such as ASCII, that do not follow this, but you cannot
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219 define new ones like this.) Defaults to 94. Note that if the dimension
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220 is 2, the character set thus described is 94x94 or 96x96.
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221 @item columns
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222 Number of columns used to display a character in this charset.
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223 Only used in TTY mode. (Under X, the actual width of a character
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224 can be derived from the font used to display the characters.)
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225 If unspecified, defaults to the dimension. (This is almost
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226 always the correct value, because character sets with dimension 2
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227 are usually ideograph character sets, which need two columns to
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228 display the intricate ideographs.)
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229 @item direction
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230 A symbol, either @code{l2r} (left-to-right) or @code{r2l}
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231 (right-to-left). Defaults to @code{l2r}. This specifies the
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232 direction that the text should be displayed in, and will be
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233 left-to-right for most charsets but right-to-left for Hebrew
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234 and Arabic. (Right-to-left display is not currently implemented.)
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235 @item final
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236 Final byte of the standard ISO 2022 escape sequence designating this
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237 charset. Must be supplied. Each combination of (@var{dimension},
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238 @var{chars}) defines a separate namespace for final bytes, and each
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239 charset within a particular namespace must have a different final byte.
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240 Note that ISO 2022 restricts the final byte to the range 0x30 - 0x7E if
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241 dimension == 1, and 0x30 - 0x5F if dimension == 2. Note also that final
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242 bytes in the range 0x30 - 0x3F are reserved for user-defined (not
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243 official) character sets. For more information on ISO 2022, see @ref{Coding
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244 Systems}.
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245 @item graphic
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246 0 (use left half of font on output) or 1 (use right half of font on
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247 output). Defaults to 0. This specifies how to convert the position
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248 codes that index a character in a character set into an index into the
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249 font used to display the character set. With @code{graphic} set to 0,
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250 position codes 33 through 126 map to font indices 33 through 126; with
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251 it set to 1, position codes 33 through 126 map to font indices 161
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252 through 254 (i.e. the same number but with the high bit set). For
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253 example, for a font whose registry is ISO8859-1, the left half of the
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254 font (octets 0x20 - 0x7F) is the @code{ascii} charset, while the right
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255 half (octets 0xA0 - 0xFF) is the @code{latin-iso8859-1} charset.
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256 @item ccl-program
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257 A compiled CCL program used to convert a character in this charset into
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258 an index into the font. This is in addition to the @code{graphic}
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259 property. If a CCL program is defined, the position codes of a
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260 character will first be processed according to @code{graphic} and
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261 then passed through the CCL program, with the resulting values used
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262 to index the font.
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263
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264 This is used, for example, in the Big5 character set (used in Taiwan).
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265 This character set is not ISO-2022-compliant, and its size (94x157) does
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266 not fit within the maximum 96x96 size of ISO-2022-compliant character
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267 sets. As a result, XEmacs/MULE splits it (in a rather complex fashion,
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268 so as to group the most commonly used characters together) into two
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269 charset objects (@code{big5-1} and @code{big5-2}), each of size 94x94,
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270 and each charset object uses a CCL program to convert the modified
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271 position codes back into standard Big5 indices to retrieve a character
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272 from a Big5 font.
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273 @end table
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274
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275 Most of the above properties can only be changed when the charset
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276 is created. @xref{Charset Property Functions}.
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277
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278 @node Basic Charset Functions
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279 @subsection Basic Charset Functions
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280
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281 @defun find-charset charset-or-name
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282 This function retrieves the charset of the given name. If
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283 @var{charset-or-name} is a charset object, it is simply returned.
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284 Otherwise, @var{charset-or-name} should be a symbol. If there is no
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285 such charset, @code{nil} is returned. Otherwise the associated charset
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286 object is returned.
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287 @end defun
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288
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289 @defun get-charset name
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290 This function retrieves the charset of the given name. Same as
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291 @code{find-charset} except an error is signalled if there is no such
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292 charset instead of returning @code{nil}.
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293 @end defun
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294
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295 @defun charset-list
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296 This function returns a list of the names of all defined charsets.
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297 @end defun
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298
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299 @defun make-charset name doc-string props
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300 This function defines a new character set. This function is for use
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301 with Mule support. @var{name} is a symbol, the name by which the
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302 character set is normally referred. @var{doc-string} is a string
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303 describing the character set. @var{props} is a property list,
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304 describing the specific nature of the character set. The recognized
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305 properties are @code{registry}, @code{dimension}, @code{columns},
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306 @code{chars}, @code{final}, @code{graphic}, @code{direction}, and
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307 @code{ccl-program}, as previously described.
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308 @end defun
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309
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310 @defun make-reverse-direction-charset charset new-name
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311 This function makes a charset equivalent to @var{charset} but which goes
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312 in the opposite direction. @var{new-name} is the name of the new
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313 charset. The new charset is returned.
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314 @end defun
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315
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316 @defun charset-from-attributes dimension chars final &optional direction
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317 This function returns a charset with the given @var{dimension},
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318 @var{chars}, @var{final}, and @var{direction}. If @var{direction} is
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319 omitted, both directions will be checked (left-to-right will be returned
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320 if character sets exist for both directions).
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321 @end defun
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322
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323 @defun charset-reverse-direction-charset charset
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324 This function returns the charset (if any) with the same dimension,
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325 number of characters, and final byte as @var{charset}, but which is
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326 displayed in the opposite direction.
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327 @end defun
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328
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329 @node Charset Property Functions
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330 @subsection Charset Property Functions
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331
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332 All of these functions accept either a charset name or charset object.
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333
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334 @defun charset-property charset prop
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335 This function returns property @var{prop} of @var{charset}.
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336 @xref{Charset Properties}.
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337 @end defun
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338
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339 Convenience functions are also provided for retrieving individual
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340 properties of a charset.
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341
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|
|
342 @defun charset-name charset
|
|
|
343 This function returns the name of @var{charset}. This will be a symbol.
|
|
|
344 @end defun
|
|
|
345
|
|
|
346 @defun charset-doc-string charset
|
|
|
347 This function returns the doc string of @var{charset}.
|
|
|
348 @end defun
|
|
|
349
|
|
|
350 @defun charset-registry charset
|
|
|
351 This function returns the registry of @var{charset}.
|
|
|
352 @end defun
|
|
|
353
|
|
|
354 @defun charset-dimension charset
|
|
|
355 This function returns the dimension of @var{charset}.
|
|
|
356 @end defun
|
|
|
357
|
|
|
358 @defun charset-chars charset
|
|
|
359 This function returns the number of characters per dimension of
|
|
|
360 @var{charset}.
|
|
|
361 @end defun
|
|
|
362
|
|
|
363 @defun charset-columns charset
|
|
|
364 This function returns the number of display columns per character (in
|
|
|
365 TTY mode) of @var{charset}.
|
|
|
366 @end defun
|
|
|
367
|
|
|
368 @defun charset-direction charset
|
|
|
369 This function returns the display direction of @var{charset} -- either
|
|
|
370 @code{l2r} or @code{r2l}.
|
|
|
371 @end defun
|
|
|
372
|
|
|
373 @defun charset-final charset
|
|
|
374 This function returns the final byte of the ISO 2022 escape sequence
|
|
|
375 designating @var{charset}.
|
|
|
376 @end defun
|
|
|
377
|
|
|
378 @defun charset-graphic charset
|
|
|
379 This function returns either 0 or 1, depending on whether the position
|
|
|
380 codes of characters in @var{charset} map to the left or right half
|
|
|
381 of their font, respectively.
|
|
|
382 @end defun
|
|
|
383
|
|
|
384 @defun charset-ccl-program charset
|
|
|
385 This function returns the CCL program, if any, for converting
|
|
|
386 position codes of characters in @var{charset} into font indices.
|
|
|
387 @end defun
|
|
|
388
|
|
|
389 The only property of a charset that can currently be set after
|
|
|
390 the charset has been created is the CCL program.
|
|
|
391
|
|
|
392 @defun set-charset-ccl-program charset ccl-program
|
|
|
393 This function sets the @code{ccl-program} property of @var{charset} to
|
|
|
394 @var{ccl-program}.
|
|
|
395 @end defun
|
|
|
396
|
|
|
397 @node Predefined Charsets
|
|
|
398 @subsection Predefined Charsets
|
|
|
399
|
|
|
400 The following charsets are predefined in the C code.
|
|
|
401
|
|
|
402 @example
|
|
54
|
403 Name Type Fi Gr Dir Registry
|
|
0
|
404 --------------------------------------------------------------
|
|
54
|
405 ascii 94 B 0 l2r ISO8859-1
|
|
|
406 control-1 94 0 l2r ---
|
|
114
|
407 latin-iso8859-1 94 A 1 l2r ISO8859-1
|
|
|
408 latin-iso8859-2 96 B 1 l2r ISO8859-2
|
|
|
409 latin-iso8859-3 96 C 1 l2r ISO8859-3
|
|
|
410 latin-iso8859-4 96 D 1 l2r ISO8859-4
|
|
|
411 cyrillic-iso8859-5 96 L 1 l2r ISO8859-5
|
|
|
412 arabic-iso8859-6 96 G 1 r2l ISO8859-6
|
|
|
413 greek-iso8859-7 96 F 1 l2r ISO8859-7
|
|
|
414 hebrew-iso8859-8 96 H 1 r2l ISO8859-8
|
|
|
415 latin-iso8859-9 96 M 1 l2r ISO8859-9
|
|
|
416 thai-tis620 96 T 1 l2r TIS620
|
|
|
417 katakana-jisx0201 94 I 1 l2r JISX0201.1976
|
|
|
418 latin-jisx0201 94 J 0 l2r JISX0201.1976
|
|
54
|
419 japanese-jisx0208-1978 94x94 @@ 0 l2r JISX0208.1978
|
|
|
420 japanese-jisx0208 94x94 B 0 l2r JISX0208.19(83|90)
|
|
|
421 japanese-jisx0212 94x94 D 0 l2r JISX0212
|
|
114
|
422 chinese-gb2312 94x94 A 0 l2r GB2312
|
|
54
|
423 chinese-cns11643-1 94x94 G 0 l2r CNS11643.1
|
|
|
424 chinese-cns11643-2 94x94 H 0 l2r CNS11643.2
|
|
|
425 chinese-big5-1 94x94 0 0 l2r Big5
|
|
|
426 chinese-big5-2 94x94 1 0 l2r Big5
|
|
|
427 korean-ksc5601 94x94 C 0 l2r KSC5601
|
|
|
428 composite 96x96 0 l2r ---
|
|
0
|
429 @end example
|
|
|
430
|
|
|
431 The following charsets are predefined in the Lisp code.
|
|
|
432
|
|
|
433 @example
|
|
54
|
434 Name Type Fi Gr Dir Registry
|
|
0
|
435 --------------------------------------------------------------
|
|
54
|
436 arabic-digit 94 2 0 l2r MuleArabic-0
|
|
|
437 arabic-1-column 94 3 0 r2l MuleArabic-1
|
|
|
438 arabic-2-column 94 4 0 r2l MuleArabic-2
|
|
|
439 sisheng 94 0 0 l2r sisheng_cwnn\|OMRON_UDC_ZH
|
|
|
440 chinese-cns11643-3 94x94 I 0 l2r CNS11643.1
|
|
|
441 chinese-cns11643-4 94x94 J 0 l2r CNS11643.1
|
|
|
442 chinese-cns11643-5 94x94 K 0 l2r CNS11643.1
|
|
|
443 chinese-cns11643-6 94x94 L 0 l2r CNS11643.1
|
|
|
444 chinese-cns11643-7 94x94 M 0 l2r CNS11643.1
|
|
|
445 ethiopic 94x94 2 0 l2r Ethio
|
|
|
446 ascii-r2l 94 B 0 r2l ISO8859-1
|
|
|
447 ipa 96 0 1 l2r MuleIPA
|
|
|
448 vietnamese-lower 96 1 1 l2r VISCII1.1
|
|
|
449 vietnamese-upper 96 2 1 l2r VISCII1.1
|
|
0
|
450 @end example
|
|
|
451
|
|
|
452 For all of the above charsets, the dimension and number of columns are
|
|
|
453 the same.
|
|
|
454
|
|
|
455 Note that ASCII, Control-1, and Composite are handled specially.
|
|
|
456 This is why some of the fields are blank; and some of the filled-in
|
|
|
457 fields (e.g. the type) are not really accurate.
|
|
|
458
|
|
|
459 @node MULE Characters
|
|
|
460 @section MULE Characters
|
|
|
461
|
|
|
462 @defun make-char charset arg1 &optional arg2
|
|
|
463 This function makes a multi-byte character from @var{charset} and octets
|
|
|
464 @var{arg1} and @var{arg2}.
|
|
|
465 @end defun
|
|
|
466
|
|
|
467 @defun char-charset ch
|
|
|
468 This function returns the character set of char @var{ch}.
|
|
|
469 @end defun
|
|
|
470
|
|
|
471 @defun char-octet ch &optional n
|
|
|
472 This function returns the octet (i.e. position code) numbered @var{n}
|
|
|
473 (should be 0 or 1) of char @var{ch}. @var{n} defaults to 0 if omitted.
|
|
|
474 @end defun
|
|
|
475
|
|
114
|
476 @defun find-charset-region start end &optional buffer
|
|
0
|
477 This function returns a list of the charsets in the region between
|
|
|
478 @var{start} and @var{end}. @var{buffer} defaults to the current buffer
|
|
|
479 if omitted.
|
|
|
480 @end defun
|
|
|
481
|
|
114
|
482 @defun find-charset-string string
|
|
0
|
483 This function returns a list of the charsets in @var{string}.
|
|
|
484 @end defun
|
|
|
485
|
|
|
486 @node Composite Characters
|
|
|
487 @section Composite Characters
|
|
|
488
|
|
|
489 Composite characters are not yet completely implemented.
|
|
|
490
|
|
|
491 @defun make-composite-char string
|
|
|
492 This function converts a string into a single composite character. The
|
|
|
493 character is the result of overstriking all the characters in the
|
|
|
494 string.
|
|
|
495 @end defun
|
|
|
496
|
|
|
497 @defun composite-char-string ch
|
|
|
498 This function returns a string of the characters comprising a composite
|
|
|
499 character.
|
|
|
500 @end defun
|
|
|
501
|
|
|
502 @defun compose-region start end &optional buffer
|
|
|
503 This function composes the characters in the region from @var{start} to
|
|
|
504 @var{end} in @var{buffer} into one composite character. The composite
|
|
|
505 character replaces the composed characters. @var{buffer} defaults to
|
|
|
506 the current buffer if omitted.
|
|
|
507 @end defun
|
|
|
508
|
|
|
509 @defun decompose-region start end &optional buffer
|
|
|
510 This function decomposes any composite characters in the region from
|
|
|
511 @var{start} to @var{end} in @var{buffer}. This converts each composite
|
|
|
512 character into one or more characters, the individual characters out of
|
|
|
513 which the composite character was formed. Non-composite characters are
|
|
|
514 left as-is. @var{buffer} defaults to the current buffer if omitted.
|
|
|
515 @end defun
|
|
|
516
|
|
|
517 @node ISO 2022
|
|
|
518 @section ISO 2022
|
|
|
519
|
|
54
|
520 This section briefly describes the ISO 2022 encoding standard. For more
|
|
|
521 thorough understanding, please refer to the original document of ISO
|
|
|
522 2022.
|
|
0
|
523
|
|
|
524 Character sets (@dfn{charsets}) are classified into the following four
|
|
|
525 categories, according to the number of characters of charset:
|
|
|
526 94-charset, 96-charset, 94x94-charset, and 96x96-charset.
|
|
|
527
|
|
|
528 @need 1000
|
|
|
529 @table @asis
|
|
|
530 @item 94-charset
|
|
|
531 ASCII(B), left(J) and right(I) half of JISX0201, ...
|
|
|
532 @item 96-charset
|
|
|
533 Latin-1(A), Latin-2(B), Latin-3(C), ...
|
|
|
534 @item 94x94-charset
|
|
|
535 GB2312(A), JISX0208(B), KSC5601(C), ...
|
|
|
536 @item 96x96-charset
|
|
|
537 none for the moment
|
|
|
538 @end table
|
|
|
539
|
|
|
540 The character in parentheses after the name of each charset
|
|
|
541 is the @dfn{final character} @var{F}, which can be regarded as
|
|
|
542 the identifier of the charset. ECMA allocates @var{F} to each
|
|
|
543 charset. @var{F} is in the range of 0x30..0x7F, but 0x30..0x3F
|
|
|
544 are only for private use.
|
|
|
545
|
|
|
546 Note: @dfn{ECMA} = European Computer Manufacturers Association
|
|
|
547
|
|
|
548 There are four @dfn{registers of charsets}, called G0 thru G3.
|
|
|
549 You can designate (or assign) any charset to one of these
|
|
|
550 registers.
|
|
|
551
|
|
|
552 The code space contained within one octet (of size 256) is divided into
|
|
|
553 4 areas: C0, GL, C1, and GR. GL and GR are the areas into which a
|
|
|
554 register of charset can be invoked into.
|
|
|
555
|
|
|
556 @example
|
|
|
557 @group
|
|
|
558 C0: 0x00 - 0x1F
|
|
|
559 GL: 0x20 - 0x7F
|
|
|
560 C1: 0x80 - 0x9F
|
|
|
561 GR: 0xA0 - 0xFF
|
|
|
562 @end group
|
|
|
563 @end example
|
|
|
564
|
|
|
565 Usually, in the initial state, G0 is invoked into GL, and G1
|
|
|
566 is invoked into GR.
|
|
|
567
|
|
54
|
568 ISO 2022 distinguishes 7-bit environments and 8-bit environments. In
|
|
|
569 7-bit environments, only C0 and GL are used.
|
|
0
|
570
|
|
|
571 Charset designation is done by escape sequences of the form:
|
|
|
572
|
|
|
573 @example
|
|
|
574 ESC [@var{I}] @var{I} @var{F}
|
|
|
575 @end example
|
|
|
576
|
|
|
577 where @var{I} is an intermediate character in the range 0x20 - 0x2F, and
|
|
|
578 @var{F} is the final character identifying this charset.
|
|
|
579
|
|
|
580 The meaning of intermediate characters are:
|
|
|
581
|
|
|
582 @example
|
|
|
583 @group
|
|
|
584 $ [0x24]: indicate charset of dimension 2 (94x94 or 96x96).
|
|
|
585 ( [0x28]: designate to G0 a 94-charset whose final byte is @var{F}.
|
|
|
586 ) [0x29]: designate to G1 a 94-charset whose final byte is @var{F}.
|
|
|
587 * [0x2A]: designate to G2 a 94-charset whose final byte is @var{F}.
|
|
|
588 + [0x2B]: designate to G3 a 94-charset whose final byte is @var{F}.
|
|
|
589 - [0x2D]: designate to G1 a 96-charset whose final byte is @var{F}.
|
|
|
590 . [0x2E]: designate to G2 a 96-charset whose final byte is @var{F}.
|
|
54
|
591 / [0x2F]: designate to G3 a 96-charset whose final byte is @var{F}.
|
|
0
|
592 @end group
|
|
|
593 @end example
|
|
|
594
|
|
54
|
595 The following rule is not allowed in ISO 2022 but can be used in Mule.
|
|
0
|
596
|
|
|
597 @example
|
|
|
598 , [0x2C]: designate to G0 a 96-charset whose final byte is @var{F}.
|
|
|
599 @end example
|
|
|
600
|
|
|
601 Here are examples of designations:
|
|
|
602
|
|
|
603 @example
|
|
|
604 @group
|
|
|
605 ESC ( B : designate to G0 ASCII
|
|
|
606 ESC - A : designate to G1 Latin-1
|
|
|
607 ESC $ ( A or ESC $ A : designate to G0 GB2312
|
|
|
608 ESC $ ( B or ESC $ B : designate to G0 JISX0208
|
|
|
609 ESC $ ) C : designate to G1 KSC5601
|
|
|
610 @end group
|
|
|
611 @end example
|
|
|
612
|
|
54
|
613 To use a charset designated to G2 or G3, and to use a charset designated
|
|
|
614 to G1 in a 7-bit environment, you must explicitly invoke G1, G2, or G3
|
|
|
615 into GL. There are two types of invocation, Locking Shift (forever) and
|
|
|
616 Single Shift (one character only).
|
|
0
|
617
|
|
|
618 Locking Shift is done as follows:
|
|
|
619
|
|
|
620 @example
|
|
54
|
621 LS0 or SI (0x0F): invoke G0 into GL
|
|
|
622 LS1 or SO (0x0E): invoke G1 into GL
|
|
0
|
623 LS2: invoke G2 into GL
|
|
|
624 LS3: invoke G3 into GL
|
|
|
625 LS1R: invoke G1 into GR
|
|
|
626 LS2R: invoke G2 into GR
|
|
|
627 LS3R: invoke G3 into GR
|
|
|
628 @end example
|
|
|
629
|
|
|
630 Single Shift is done as follows:
|
|
|
631
|
|
|
632 @example
|
|
|
633 @group
|
|
|
634 SS2 or ESC N: invoke G2 into GL
|
|
|
635 SS3 or ESC O: invoke G3 into GL
|
|
|
636 @end group
|
|
|
637 @end example
|
|
|
638
|
|
|
639 (#### Ben says: I think the above is slightly incorrect. It appears that
|
|
|
640 SS2 invokes G2 into GR and SS3 invokes G3 into GR, whereas ESC N and
|
|
|
641 ESC O behave as indicated. The above definitions will not parse
|
|
|
642 EUC-encoded text correctly, and it looks like the code in mule-coding.c
|
|
|
643 has similar problems.)
|
|
|
644
|
|
54
|
645 You may realize that there are a lot of ISO-2022-compliant ways of
|
|
0
|
646 encoding multilingual text. Now, in the world, there exist many coding
|
|
|
647 systems such as X11's Compound Text, Japanese JUNET code, and so-called
|
|
54
|
648 EUC (Extended UNIX Code); all of these are variants of ISO 2022.
|
|
0
|
649
|
|
54
|
650 In Mule, we characterize ISO 2022 by the following attributes:
|
|
0
|
651
|
|
|
652 @enumerate
|
|
|
653 @item
|
|
|
654 Initial designation to G0 thru G3.
|
|
|
655 @item
|
|
|
656 Allow designation of short form for Japanese and Chinese.
|
|
|
657 @item
|
|
|
658 Should we designate ASCII to G0 before control characters?
|
|
|
659 @item
|
|
|
660 Should we designate ASCII to G0 at the end of line?
|
|
|
661 @item
|
|
|
662 7-bit environment or 8-bit environment.
|
|
|
663 @item
|
|
|
664 Use Locking Shift or not.
|
|
|
665 @item
|
|
|
666 Use ASCII or JIS0201-1976-Roman.
|
|
|
667 @item
|
|
|
668 Use JISX0208-1983 or JISX0208-1976.
|
|
|
669 @end enumerate
|
|
|
670
|
|
|
671 (The last two are only for Japanese.)
|
|
|
672
|
|
|
673 By specifying these attributes, you can create any variant
|
|
54
|
674 of ISO 2022.
|
|
0
|
675
|
|
|
676 Here are several examples:
|
|
|
677
|
|
|
678 @example
|
|
|
679 @group
|
|
|
680 junet -- Coding system used in JUNET.
|
|
|
681 1. G0 <- ASCII, G1..3 <- never used
|
|
|
682 2. Yes.
|
|
|
683 3. Yes.
|
|
|
684 4. Yes.
|
|
|
685 5. 7-bit environment
|
|
|
686 6. No.
|
|
|
687 7. Use ASCII
|
|
|
688 8. Use JISX0208-1983
|
|
|
689 @end group
|
|
|
690
|
|
|
691 @group
|
|
|
692 ctext -- Compound Text
|
|
|
693 1. G0 <- ASCII, G1 <- Latin-1, G2,3 <- never used
|
|
|
694 2. No.
|
|
|
695 3. No.
|
|
|
696 4. Yes.
|
|
|
697 5. 8-bit environment
|
|
|
698 6. No.
|
|
|
699 7. Use ASCII
|
|
|
700 8. Use JISX0208-1983
|
|
|
701 @end group
|
|
|
702
|
|
|
703 @group
|
|
|
704 euc-china -- Chinese EUC. Although many people call this
|
|
|
705 as "GB encoding", the name may cause misunderstanding.
|
|
|
706 1. G0 <- ASCII, G1 <- GB2312, G2,3 <- never used
|
|
|
707 2. No.
|
|
|
708 3. Yes.
|
|
|
709 4. Yes.
|
|
|
710 5. 8-bit environment
|
|
|
711 6. No.
|
|
|
712 7. Use ASCII
|
|
|
713 8. Use JISX0208-1983
|
|
|
714 @end group
|
|
|
715
|
|
|
716 @group
|
|
|
717 korean-mail -- Coding system used in Korean network.
|
|
|
718 1. G0 <- ASCII, G1 <- KSC5601, G2,3 <- never used
|
|
|
719 2. No.
|
|
|
720 3. Yes.
|
|
|
721 4. Yes.
|
|
|
722 5. 7-bit environment
|
|
|
723 6. Yes.
|
|
|
724 7. No.
|
|
|
725 8. No.
|
|
|
726 @end group
|
|
|
727 @end example
|
|
|
728
|
|
|
729 Mule creates all these coding systems by default.
|
|
|
730
|
|
|
731 @node Coding Systems
|
|
|
732 @section Coding Systems
|
|
|
733
|
|
|
734 A coding system is an object that defines how text containing multiple
|
|
|
735 character sets is encoded into a stream of (typically 8-bit) bytes. The
|
|
|
736 coding system is used to decode the stream into a series of characters
|
|
|
737 (which may be from multiple charsets) when the text is read from a file
|
|
|
738 or process, and is used to encode the text back into the same format
|
|
|
739 when it is written out to a file or process.
|
|
|
740
|
|
54
|
741 For example, many ISO-2022-compliant coding systems (such as Compound
|
|
0
|
742 Text, which is used for inter-client data under the X Window System) use
|
|
|
743 escape sequences to switch between different charsets -- Japanese Kanji,
|
|
|
744 for example, is invoked with @samp{ESC $ ( B}; ASCII is invoked with
|
|
|
745 @samp{ESC ( B}; and Cyrillic is invoked with @samp{ESC - L}. See
|
|
|
746 @code{make-coding-system} for more information.
|
|
|
747
|
|
|
748 Coding systems are normally identified using a symbol, and the symbol is
|
|
|
749 accepted in place of the actual coding system object whenever a coding
|
|
|
750 system is called for. (This is similar to how faces and charsets work.)
|
|
|
751
|
|
|
752 @defun coding-system-p object
|
|
|
753 This function returns non-@code{nil} if @var{object} is a coding system.
|
|
|
754 @end defun
|
|
|
755
|
|
|
756 @menu
|
|
|
757 * Coding System Types:: Classifying coding systems.
|
|
|
758 * EOL Conversion:: Dealing with different ways of denoting
|
|
|
759 the end of a line.
|
|
|
760 * Coding System Properties:: Properties of a coding system.
|
|
|
761 * Basic Coding System Functions:: Working with coding systems.
|
|
|
762 * Coding System Property Functions:: Retrieving a coding system's properties.
|
|
|
763 * Encoding and Decoding Text:: Encoding and decoding text.
|
|
|
764 * Detection of Textual Encoding:: Determining how text is encoded.
|
|
|
765 * Big5 and Shift-JIS Functions:: Special functions for these non-standard
|
|
|
766 encodings.
|
|
|
767 @end menu
|
|
|
768
|
|
|
769 @node Coding System Types
|
|
|
770 @subsection Coding System Types
|
|
|
771
|
|
|
772 @table @code
|
|
|
773 @item nil
|
|
|
774 @itemx autodetect
|
|
|
775 Automatic conversion. XEmacs attempts to detect the coding system used
|
|
|
776 in the file.
|
|
54
|
777 @item no-conversion
|
|
0
|
778 No conversion. Use this for binary files and such. On output, graphic
|
|
|
779 characters that are not in ASCII or Latin-1 will be replaced by a
|
|
114
|
780 @samp{?}. (For a no-conversion-encoded buffer, these characters will
|
|
|
781 only be present if you explicitly insert them.)
|
|
0
|
782 @item shift-jis
|
|
|
783 Shift-JIS (a Japanese encoding commonly used in PC operating systems).
|
|
|
784 @item iso2022
|
|
54
|
785 Any ISO-2022-compliant encoding. Among other things, this includes JIS
|
|
|
786 (the Japanese encoding commonly used for e-mail), national variants of
|
|
|
787 EUC (the standard Unix encoding for Japanese and other languages), and
|
|
|
788 Compound Text (an encoding used in X11). You can specify more specific
|
|
|
789 information about the conversion with the @var{flags} argument.
|
|
0
|
790 @item big5
|
|
|
791 Big5 (the encoding commonly used for Taiwanese).
|
|
|
792 @item ccl
|
|
|
793 The conversion is performed using a user-written pseudo-code program.
|
|
|
794 CCL (Code Conversion Language) is the name of this pseudo-code.
|
|
|
795 @item internal
|
|
|
796 Write out or read in the raw contents of the memory representing the
|
|
|
797 buffer's text. This is primarily useful for debugging purposes, and is
|
|
|
798 only enabled when XEmacs has been compiled with @code{DEBUG_XEMACS} set
|
|
|
799 (the @samp{--debug} configure option). @strong{Warning}: Reading in a
|
|
|
800 file using @code{internal} conversion can result in an internal
|
|
|
801 inconsistency in the memory representing a buffer's text, which will
|
|
|
802 produce unpredictable results and may cause XEmacs to crash. Under
|
|
|
803 normal circumstances you should never use @code{internal} conversion.
|
|
|
804 @end table
|
|
|
805
|
|
|
806 @node EOL Conversion
|
|
|
807 @subsection EOL Conversion
|
|
|
808
|
|
|
809 @table @code
|
|
|
810 @item nil
|
|
|
811 Automatically detect the end-of-line type (LF, CRLF, or CR). Also
|
|
|
812 generate subsidiary coding systems named @code{@var{name}-unix},
|
|
|
813 @code{@var{name}-dos}, and @code{@var{name}-mac}, that are identical to
|
|
|
814 this coding system but have an EOL-TYPE value of @code{lf}, @code{crlf},
|
|
|
815 and @code{cr}, respectively.
|
|
|
816 @item lf
|
|
|
817 The end of a line is marked externally using ASCII LF. Since this is
|
|
|
818 also the way that XEmacs represents an end-of-line internally,
|
|
|
819 specifying this option results in no end-of-line conversion. This is
|
|
|
820 the standard format for Unix text files.
|
|
|
821 @item crlf
|
|
|
822 The end of a line is marked externally using ASCII CRLF. This is the
|
|
|
823 standard format for MS-DOS text files.
|
|
|
824 @item cr
|
|
|
825 The end of a line is marked externally using ASCII CR. This is the
|
|
|
826 standard format for Macintosh text files.
|
|
|
827 @item t
|
|
|
828 Automatically detect the end-of-line type but do not generate subsidiary
|
|
|
829 coding systems. (This value is converted to @code{nil} when stored
|
|
|
830 internally, and @code{coding-system-property} will return @code{nil}.)
|
|
|
831 @end table
|
|
|
832
|
|
|
833 @node Coding System Properties
|
|
|
834 @subsection Coding System Properties
|
|
|
835
|
|
|
836 @table @code
|
|
|
837 @item mnemonic
|
|
|
838 String to be displayed in the modeline when this coding system is
|
|
|
839 active.
|
|
|
840
|
|
|
841 @item eol-type
|
|
|
842 End-of-line conversion to be used. It should be one of the types
|
|
|
843 listed in @ref{EOL Conversion}.
|
|
|
844
|
|
|
845 @item post-read-conversion
|
|
|
846 Function called after a file has been read in, to perform the decoding.
|
|
|
847 Called with two arguments, @var{beg} and @var{end}, denoting a region of
|
|
|
848 the current buffer to be decoded.
|
|
|
849
|
|
|
850 @item pre-write-conversion
|
|
|
851 Function called before a file is written out, to perform the encoding.
|
|
|
852 Called with two arguments, @var{beg} and @var{end}, denoting a region of
|
|
|
853 the current buffer to be encoded.
|
|
|
854 @end table
|
|
|
855
|
|
|
856 The following additional properties are recognized if @var{type} is
|
|
|
857 @code{iso2022}:
|
|
|
858
|
|
|
859 @table @code
|
|
|
860 @item charset-g0
|
|
|
861 @itemx charset-g1
|
|
|
862 @itemx charset-g2
|
|
|
863 @itemx charset-g3
|
|
|
864 The character set initially designated to the G0 - G3 registers.
|
|
|
865 The value should be one of
|
|
|
866
|
|
|
867 @itemize @bullet
|
|
|
868 @item
|
|
|
869 A charset object (designate that character set)
|
|
|
870 @item
|
|
|
871 @code{nil} (do not ever use this register)
|
|
|
872 @item
|
|
|
873 @code{t} (no character set is initially designated to the register, but
|
|
|
874 may be later on; this automatically sets the corresponding
|
|
|
875 @code{force-g*-on-output} property)
|
|
|
876 @end itemize
|
|
|
877
|
|
|
878 @item force-g0-on-output
|
|
|
879 @itemx force-g1-on-output
|
|
|
880 @itemx force-g2-on-output
|
|
54
|
881 @itemx force-g3-on-output
|
|
0
|
882 If non-@code{nil}, send an explicit designation sequence on output
|
|
|
883 before using the specified register.
|
|
|
884
|
|
|
885 @item short
|
|
|
886 If non-@code{nil}, use the short forms @samp{ESC $ @@}, @samp{ESC $ A},
|
|
|
887 and @samp{ESC $ B} on output in place of the full designation sequences
|
|
|
888 @samp{ESC $ ( @@}, @samp{ESC $ ( A}, and @samp{ESC $ ( B}.
|
|
|
889
|
|
|
890 @item no-ascii-eol
|
|
|
891 If non-@code{nil}, don't designate ASCII to G0 at each end of line on
|
|
|
892 output. Setting this to non-@code{nil} also suppresses other
|
|
|
893 state-resetting that normally happens at the end of a line.
|
|
|
894
|
|
|
895 @item no-ascii-cntl
|
|
|
896 If non-@code{nil}, don't designate ASCII to G0 before control chars on
|
|
|
897 output.
|
|
|
898
|
|
|
899 @item seven
|
|
|
900 If non-@code{nil}, use 7-bit environment on output. Otherwise, use 8-bit
|
|
|
901 environment.
|
|
|
902
|
|
|
903 @item lock-shift
|
|
|
904 If non-@code{nil}, use locking-shift (SO/SI) instead of single-shift or
|
|
|
905 designation by escape sequence.
|
|
|
906
|
|
|
907 @item no-iso6429
|
|
|
908 If non-@code{nil}, don't use ISO6429's direction specification.
|
|
|
909
|
|
|
910 @item escape-quoted
|
|
|
911 If non-nil, literal control characters that are the same as the
|
|
54
|
912 beginning of a recognized ISO 2022 or ISO 6429 escape sequence (in
|
|
0
|
913 particular, ESC (0x1B), SO (0x0E), SI (0x0F), SS2 (0x8E), SS3 (0x8F),
|
|
|
914 and CSI (0x9B)) are ``quoted'' with an escape character so that they can
|
|
|
915 be properly distinguished from an escape sequence. (Note that doing
|
|
|
916 this results in a non-portable encoding.) This encoding flag is used for
|
|
|
917 byte-compiled files. Note that ESC is a good choice for a quoting
|
|
|
918 character because there are no escape sequences whose second byte is a
|
|
|
919 character from the Control-0 or Control-1 character sets; this is
|
|
54
|
920 explicitly disallowed by the ISO 2022 standard.
|
|
0
|
921
|
|
|
922 @item input-charset-conversion
|
|
|
923 A list of conversion specifications, specifying conversion of characters
|
|
|
924 in one charset to another when decoding is performed. Each
|
|
|
925 specification is a list of two elements: the source charset, and the
|
|
|
926 destination charset.
|
|
|
927
|
|
|
928 @item output-charset-conversion
|
|
|
929 A list of conversion specifications, specifying conversion of characters
|
|
|
930 in one charset to another when encoding is performed. The form of each
|
|
|
931 specification is the same as for @code{input-charset-conversion}.
|
|
|
932 @end table
|
|
|
933
|
|
|
934 The following additional properties are recognized (and required) if
|
|
|
935 @var{type} is @code{ccl}:
|
|
|
936
|
|
|
937 @table @code
|
|
|
938 @item decode
|
|
|
939 CCL program used for decoding (converting to internal format).
|
|
|
940
|
|
|
941 @item encode
|
|
|
942 CCL program used for encoding (converting to external format).
|
|
|
943 @end table
|
|
|
944
|
|
|
945 @node Basic Coding System Functions
|
|
|
946 @subsection Basic Coding System Functions
|
|
|
947
|
|
|
948 @defun find-coding-system coding-system-or-name
|
|
|
949 This function retrieves the coding system of the given name.
|
|
|
950
|
|
|
951 If @var{coding-system-or-name} is a coding-system object, it is simply
|
|
|
952 returned. Otherwise, @var{coding-system-or-name} should be a symbol.
|
|
|
953 If there is no such coding system, @code{nil} is returned. Otherwise
|
|
|
954 the associated coding system object is returned.
|
|
|
955 @end defun
|
|
|
956
|
|
|
957 @defun get-coding-system name
|
|
|
958 This function retrieves the coding system of the given name. Same as
|
|
|
959 @code{find-coding-system} except an error is signalled if there is no
|
|
|
960 such coding system instead of returning @code{nil}.
|
|
|
961 @end defun
|
|
|
962
|
|
|
963 @defun coding-system-list
|
|
|
964 This function returns a list of the names of all defined coding systems.
|
|
|
965 @end defun
|
|
|
966
|
|
|
967 @defun coding-system-name coding-system
|
|
|
968 This function returns the name of the given coding system.
|
|
|
969 @end defun
|
|
|
970
|
|
|
971 @defun make-coding-system name type &optional doc-string props
|
|
|
972 This function registers symbol @var{name} as a coding system.
|
|
|
973
|
|
|
974 @var{type} describes the conversion method used and should be one of
|
|
|
975 the types listed in @ref{Coding System Types}.
|
|
|
976
|
|
|
977 @var{doc-string} is a string describing the coding system.
|
|
|
978
|
|
|
979 @var{props} is a property list, describing the specific nature of the
|
|
|
980 character set. Recognized properties are as in @ref{Coding System
|
|
|
981 Properties}.
|
|
|
982 @end defun
|
|
|
983
|
|
|
984 @defun copy-coding-system old-coding-system new-name
|
|
|
985 This function copies @var{old-coding-system} to @var{new-name}. If
|
|
|
986 @var{new-name} does not name an existing coding system, a new one will
|
|
|
987 be created.
|
|
|
988 @end defun
|
|
|
989
|
|
|
990 @defun subsidiary-coding-system coding-system eol-type
|
|
|
991 This function returns the subsidiary coding system of
|
|
|
992 @var{coding-system} with eol type @var{eol-type}.
|
|
|
993 @end defun
|
|
|
994
|
|
|
995 @node Coding System Property Functions
|
|
|
996 @subsection Coding System Property Functions
|
|
|
997
|
|
|
998 @defun coding-system-doc-string coding-system
|
|
|
999 This function returns the doc string for @var{coding-system}.
|
|
|
1000 @end defun
|
|
|
1001
|
|
|
1002 @defun coding-system-type coding-system
|
|
|
1003 This function returns the type of @var{coding-system}.
|
|
|
1004 @end defun
|
|
|
1005
|
|
|
1006 @defun coding-system-property coding-system prop
|
|
|
1007 This function returns the @var{prop} property of @var{coding-system}.
|
|
|
1008 @end defun
|
|
|
1009
|
|
|
1010 @node Encoding and Decoding Text
|
|
|
1011 @subsection Encoding and Decoding Text
|
|
|
1012
|
|
|
1013 @defun decode-coding-region start end coding-system &optional buffer
|
|
|
1014 This function decodes the text between @var{start} and @var{end} which
|
|
|
1015 is encoded in @var{coding-system}. This is useful if you've read in
|
|
|
1016 encoded text from a file without decoding it (e.g. you read in a
|
|
54
|
1017 JIS-formatted file but used the @code{binary} or @code{no-conversion} coding
|
|
0
|
1018 system, so that it shows up as @samp{^[$B!<!+^[(B}). The length of the
|
|
|
1019 encoded text is returned. @var{buffer} defaults to the current buffer
|
|
|
1020 if unspecified.
|
|
|
1021 @end defun
|
|
|
1022
|
|
|
1023 @defun encode-coding-region start end coding-system &optional buffer
|
|
|
1024 This function encodes the text between @var{start} and @var{end} using
|
|
|
1025 @var{coding-system}. This will, for example, convert Japanese
|
|
|
1026 characters into stuff such as @samp{^[$B!<!+^[(B} if you use the JIS
|
|
|
1027 encoding. The length of the encoded text is returned. @var{buffer}
|
|
|
1028 defaults to the current buffer if unspecified.
|
|
|
1029 @end defun
|
|
|
1030
|
|
|
1031 @node Detection of Textual Encoding
|
|
|
1032 @subsection Detection of Textual Encoding
|
|
|
1033
|
|
|
1034 @defun coding-category-list
|
|
|
1035 This function returns a list of all recognized coding categories.
|
|
|
1036 @end defun
|
|
|
1037
|
|
|
1038 @defun set-coding-priority-list list
|
|
|
1039 This function changes the priority order of the coding categories.
|
|
|
1040 @var{list} should be a list of coding categories, in descending order of
|
|
|
1041 priority. Unspecified coding categories will be lower in priority than
|
|
|
1042 all specified ones, in the same relative order they were in previously.
|
|
|
1043 @end defun
|
|
|
1044
|
|
|
1045 @defun coding-priority-list
|
|
|
1046 This function returns a list of coding categories in descending order of
|
|
|
1047 priority.
|
|
|
1048 @end defun
|
|
|
1049
|
|
|
1050 @defun set-coding-category-system coding-category coding-system
|
|
|
1051 This function changes the coding system associated with a coding category.
|
|
|
1052 @end defun
|
|
|
1053
|
|
|
1054 @defun coding-category-system coding-category
|
|
|
1055 This function returns the coding system associated with a coding category.
|
|
|
1056 @end defun
|
|
|
1057
|
|
|
1058 @defun detect-coding-region start end &optional buffer
|
|
|
1059 This function detects coding system of the text in the region between
|
|
|
1060 @var{start} and @var{end}. Returned value is a list of possible coding
|
|
|
1061 systems ordered by priority. If only ASCII characters are found, it
|
|
|
1062 returns @code{autodetect} or one of its subsidiary coding systems
|
|
|
1063 according to a detected end-of-line type. Optional arg @var{buffer}
|
|
|
1064 defaults to the current buffer.
|
|
|
1065 @end defun
|
|
|
1066
|
|
|
1067 @node Big5 and Shift-JIS Functions
|
|
|
1068 @subsection Big5 and Shift-JIS Functions
|
|
|
1069
|
|
|
1070 These are special functions for working with the non-standard
|
|
|
1071 Shift-JIS and Big5 encodings.
|
|
|
1072
|
|
|
1073 @defun decode-shift-jis-char code
|
|
|
1074 This function decodes a JISX0208 character of Shift-JIS coding-system.
|
|
|
1075 @var{code} is the character code in Shift-JIS as a cons of type bytes.
|
|
|
1076 The corresponding character is returned.
|
|
|
1077 @end defun
|
|
|
1078
|
|
|
1079 @defun encode-shift-jis-char ch
|
|
|
1080 This function encodes a JISX0208 character @var{ch} to SHIFT-JIS
|
|
|
1081 coding-system. The corresponding character code in SHIFT-JIS is
|
|
|
1082 returned as a cons of two bytes.
|
|
|
1083 @end defun
|
|
|
1084
|
|
|
1085 @defun decode-big5-char code
|
|
|
1086 This function decodes a Big5 character @var{code} of BIG5 coding-system.
|
|
|
1087 @var{code} is the character code in BIG5. The corresponding character
|
|
|
1088 is returned.
|
|
|
1089 @end defun
|
|
|
1090
|
|
|
1091 @defun encode-big5-char ch
|
|
|
1092 This function encodes the Big5 character @var{char} to BIG5
|
|
|
1093 coding-system. The corresponding character code in Big5 is returned.
|
|
|
1094 @end defun
|
|
|
1095
|
|
343
|
1096 @node CCL, Category Tables, Coding Systems, MULE
|
|
0
|
1097 @section CCL
|
|
|
1098
|
|
343
|
1099 CCL (Code Conversion Language) is a simple structured programming
|
|
|
1100 language designed for character coding conversions. A CCL program is
|
|
|
1101 compiled to CCL code (represented by a vector of integers) and executed
|
|
|
1102 by the CCL interpreter embedded in Emacs. The CCL interpreter
|
|
|
1103 implements a virtual machine with 8 registers called @code{r0}, ...,
|
|
|
1104 @code{r7}, a number of control structures, and some I/O operators. Take
|
|
|
1105 care when using registers @code{r0} (used in implicit @dfn{set}
|
|
|
1106 statements) and especially @code{r7} (used internally by several
|
|
|
1107 statements and operations, especially for multiple return values and I/O
|
|
|
1108 operations).
|
|
|
1109
|
|
|
1110 CCL is used for code conversion during process I/O and file I/O for
|
|
|
1111 non-ISO2022 coding systems. (It is the only way for a user to specify a
|
|
|
1112 code conversion function.) It is also used for calculating the code
|
|
|
1113 point of an X11 font from a character code. However, since CCL is
|
|
|
1114 designed as a powerful programming language, it can be used for more
|
|
|
1115 generic calculation where efficiency is demanded. A combination of
|
|
|
1116 three or more arithmetic operations can be calculated faster by CCL than
|
|
|
1117 by Emacs Lisp.
|
|
|
1118
|
|
|
1119 @strong{Warning:} The code in @file{src/mule-ccl.c} and
|
|
|
1120 @file{$packages/lisp/mule-base/mule-ccl.el} is the definitive
|
|
|
1121 description of CCL's semantics. The previous version of this section
|
|
|
1122 contained several typos and obsolete names left from earlier versions of
|
|
|
1123 MULE, and many may remain. (I am not an experienced CCL programmer; the
|
|
|
1124 few who know CCL well find writing English painful.)
|
|
|
1125
|
|
|
1126 A CCL program transforms an input data stream into an output data
|
|
|
1127 stream. The input stream, held in a buffer of constant bytes, is left
|
|
|
1128 unchanged. The buffer may be filled by an external input operation,
|
|
|
1129 taken from an Emacs buffer, or taken from a Lisp string. The output
|
|
|
1130 buffer is a dynamic array of bytes, which can be written by an external
|
|
|
1131 output operation, inserted into an Emacs buffer, or returned as a Lisp
|
|
|
1132 string.
|
|
|
1133
|
|
|
1134 A CCL program is a (Lisp) list containing two or three members. The
|
|
|
1135 first member is the @dfn{buffer magnification}, which indicates the
|
|
|
1136 required minimum size of the output buffer as a multiple of the input
|
|
|
1137 buffer. It is followed by the @dfn{main block} which executes while
|
|
|
1138 there is input remaining, and an optional @dfn{EOF block} which is
|
|
|
1139 executed when the input is exhausted. Both the main block and the EOF
|
|
|
1140 block are CCL blocks.
|
|
|
1141
|
|
|
1142 A @dfn{CCL block} is either a CCL statement or list of CCL statements.
|
|
|
1143 A @dfn{CCL statement} is either a @dfn{set statement} (either an integer
|
|
|
1144 or an @dfn{assignment}, which is a list of a register to receive the
|
|
|
1145 assignment, an assignment operator, and an expression) or a @dfn{control
|
|
|
1146 statement} (a list starting with a keyword, whose allowable syntax
|
|
|
1147 depends on the keyword).
|
|
|
1148
|
|
|
1149 @menu
|
|
|
1150 * CCL Syntax:: CCL program syntax in BNF notation.
|
|
|
1151 * CCL Statements:: Semantics of CCL statements.
|
|
|
1152 * CCL Expressions:: Operators and expressions in CCL.
|
|
|
1153 * Calling CCL:: Running CCL programs.
|
|
|
1154 * CCL Examples:: The encoding functions for Big5 and KOI-8.
|
|
|
1155 @end menu
|
|
|
1156
|
|
|
1157 @node CCL Syntax, CCL Statements, CCL, CCL
|
|
|
1158 @comment Node, Next, Previous, Up
|
|
|
1159 @subsection CCL Syntax
|
|
|
1160
|
|
|
1161 The full syntax of a CCL program in BNF notation:
|
|
|
1162
|
|
|
1163 @format
|
|
|
1164 CCL_PROGRAM :=
|
|
|
1165 (BUFFER_MAGNIFICATION
|
|
|
1166 CCL_MAIN_BLOCK
|
|
|
1167 [ CCL_EOF_BLOCK ])
|
|
|
1168
|
|
|
1169 BUFFER_MAGNIFICATION := integer
|
|
|
1170 CCL_MAIN_BLOCK := CCL_BLOCK
|
|
|
1171 CCL_EOF_BLOCK := CCL_BLOCK
|
|
|
1172
|
|
|
1173 CCL_BLOCK :=
|
|
|
1174 STATEMENT | (STATEMENT [STATEMENT ...])
|
|
|
1175 STATEMENT :=
|
|
|
1176 SET | IF | BRANCH | LOOP | REPEAT | BREAK | READ | WRITE
|
|
|
1177 | CALL | END
|
|
|
1178
|
|
|
1179 SET :=
|
|
|
1180 (REG = EXPRESSION)
|
|
|
1181 | (REG ASSIGNMENT_OPERATOR EXPRESSION)
|
|
|
1182 | integer
|
|
|
1183
|
|
|
1184 EXPRESSION := ARG | (EXPRESSION OPERATOR ARG)
|
|
|
1185
|
|
|
1186 IF := (if EXPRESSION CCL_BLOCK [CCL_BLOCK])
|
|
|
1187 BRANCH := (branch EXPRESSION CCL_BLOCK [CCL_BLOCK ...])
|
|
|
1188 LOOP := (loop STATEMENT [STATEMENT ...])
|
|
|
1189 BREAK := (break)
|
|
|
1190 REPEAT :=
|
|
|
1191 (repeat)
|
|
|
1192 | (write-repeat [REG | integer | string])
|
|
|
1193 | (write-read-repeat REG [integer | ARRAY])
|
|
|
1194 READ :=
|
|
|
1195 (read REG ...)
|
|
|
1196 | (read-if (REG OPERATOR ARG) CCL_BLOCK CCL_BLOCK)
|
|
|
1197 | (read-branch REG CCL_BLOCK [CCL_BLOCK ...])
|
|
|
1198 WRITE :=
|
|
|
1199 (write REG ...)
|
|
|
1200 | (write EXPRESSION)
|
|
|
1201 | (write integer) | (write string) | (write REG ARRAY)
|
|
|
1202 | string
|
|
|
1203 CALL := (call ccl-program-name)
|
|
|
1204 END := (end)
|
|
|
1205
|
|
|
1206 REG := r0 | r1 | r2 | r3 | r4 | r5 | r6 | r7
|
|
|
1207 ARG := REG | integer
|
|
|
1208 OPERATOR :=
|
|
|
1209 + | - | * | / | % | & | '|' | ^ | << | >> | <8 | >8 | //
|
|
|
1210 | < | > | == | <= | >= | != | de-sjis | en-sjis
|
|
|
1211 ASSIGNMENT_OPERATOR :=
|
|
|
1212 += | -= | *= | /= | %= | &= | '|=' | ^= | <<= | >>=
|
|
|
1213 ARRAY := '[' integer ... ']'
|
|
|
1214 @end format
|
|
|
1215
|
|
|
1216 @node CCL Statements, CCL Expressions, CCL Syntax, CCL
|
|
|
1217 @comment Node, Next, Previous, Up
|
|
|
1218 @subsection CCL Statements
|
|
|
1219
|
|
|
1220 The Emacs Code Conversion Language provides the following statement
|
|
|
1221 types: @dfn{set}, @dfn{if}, @dfn{branch}, @dfn{loop}, @dfn{repeat},
|
|
|
1222 @dfn{break}, @dfn{read}, @dfn{write}, @dfn{call}, and @dfn{end}.
|
|
|
1223
|
|
|
1224 @heading Set statement:
|
|
|
1225
|
|
|
1226 The @dfn{set} statement has three variants with the syntaxes
|
|
|
1227 @samp{(@var{reg} = @var{expression})},
|
|
|
1228 @samp{(@var{reg} @var{assignment_operator} @var{expression})}, and
|
|
|
1229 @samp{@var{integer}}. The assignment operator variation of the
|
|
|
1230 @dfn{set} statement works the same way as the corresponding C expression
|
|
|
1231 statement does. The assignment operators are @code{+=}, @code{-=},
|
|
|
1232 @code{*=}, @code{/=}, @code{%=}, @code{&=}, @code{|=}, @code{^=},
|
|
|
1233 @code{<<=}, and @code{>>=}, and they have the same meanings as in C. A
|
|
|
1234 "naked integer" @var{integer} is equivalent to a @var{set} statement of
|
|
|
1235 the form @code{(r0 = @var{integer})}.
|
|
|
1236
|
|
|
1237 @heading I/O statements:
|
|
|
1238
|
|
|
1239 The @dfn{read} statement takes one or more registers as arguments. It
|
|
|
1240 reads one byte (a C char) from the input into each register in turn.
|
|
|
1241
|
|
|
1242 The @dfn{write} takes several forms. In the form @samp{(write @var{reg}
|
|
|
1243 ...)} it takes one or more registers as arguments and writes each in
|
|
|
1244 turn to the output. The integer in a register (interpreted as an
|
|
|
1245 Emchar) is encoded to multibyte form (ie, Bufbytes) and written to the
|
|
|
1246 current output buffer. If it is less than 256, it is written as is.
|
|
|
1247 The forms @samp{(write @var{expression})} and @samp{(write
|
|
|
1248 @var{integer})} are treated analogously. The form @samp{(write
|
|
|
1249 @var{string})} writes the constant string to the output. A
|
|
|
1250 "naked string" @samp{@var{string}} is equivalent to the statement @samp{(write
|
|
|
1251 @var{string})}. The form @samp{(write @var{reg} @var{array})} writes
|
|
|
1252 the @var{reg}th element of the @var{array} to the output.
|
|
|
1253
|
|
|
1254 @heading Conditional statements:
|
|
|
1255
|
|
|
1256 The @dfn{if} statement takes an @var{expression}, a @var{CCL block}, and
|
|
|
1257 an optional @var{second CCL block} as arguments. If the
|
|
|
1258 @var{expression} evaluates to non-zero, the first @var{CCL block} is
|
|
|
1259 executed. Otherwise, if there is a @var{second CCL block}, it is
|
|
|
1260 executed.
|
|
|
1261
|
|
|
1262 The @dfn{read-if} variant of the @dfn{if} statement takes an
|
|
|
1263 @var{expression}, a @var{CCL block}, and an optional @var{second CCL
|
|
|
1264 block} as arguments. The @var{expression} must have the form
|
|
|
1265 @code{(@var{reg} @var{operator} @var{operand})} (where @var{operand} is
|
|
|
1266 a register or an integer). The @code{read-if} statement first reads
|
|
|
1267 from the input into the first register operand in the @var{expression},
|
|
|
1268 then conditionally executes a CCL block just as the @code{if} statement
|
|
|
1269 does.
|
|
|
1270
|
|
|
1271 The @dfn{branch} statement takes an @var{expression} and one or more CCL
|
|
|
1272 blocks as arguments. The CCL blocks are treated as a zero-indexed
|
|
|
1273 array, and the @code{branch} statement uses the @var{expression} as the
|
|
|
1274 index of the CCL block to execute. Null CCL blocks may be used as
|
|
|
1275 no-ops, continuing execution with the statement following the
|
|
|
1276 @code{branch} statement in the containing CCL block. Out-of-range
|
|
|
1277 values for the @var{EXPRESSION} are also treated as no-ops.
|
|
|
1278
|
|
|
1279 The @dfn{read-branch} variant of the @dfn{branch} statement takes an
|
|
|
1280 @var{register}, a @var{CCL block}, and an optional @var{second CCL
|
|
|
1281 block} as arguments. The @code{read-branch} statement first reads from
|
|
|
1282 the input into the @var{register}, then conditionally executes a CCL
|
|
|
1283 block just as the @code{branch} statement does.
|
|
|
1284
|
|
|
1285 @heading Loop control statements:
|
|
|
1286
|
|
|
1287 The @dfn{loop} statement creates a block with an implied jump from the
|
|
|
1288 end of the block back to its head. The loop is exited on a @code{break}
|
|
|
1289 statement, and continued without executing the tail by a @code{repeat}
|
|
|
1290 statement.
|
|
|
1291
|
|
|
1292 The @dfn{break} statement, written @samp{(break)}, terminates the
|
|
|
1293 current loop and continues with the next statement in the current
|
|
|
1294 block.
|
|
|
1295
|
|
|
1296 The @dfn{repeat} statement has three variants, @code{repeat},
|
|
|
1297 @code{write-repeat}, and @code{write-read-repeat}. Each continues the
|
|
|
1298 current loop from its head, possibly after performing I/O.
|
|
|
1299 @code{repeat} takes no arguments and does no I/O before jumping.
|
|
|
1300 @code{write-repeat} takes a single argument (a register, an
|
|
|
1301 integer, or a string), writes it to the output, then jumps.
|
|
|
1302 @code{write-read-repeat} takes one or two arguments. The first must
|
|
|
1303 be a register. The second may be an integer or an array; if absent, it
|
|
|
1304 is implicitly set to the first (register) argument.
|
|
|
1305 @code{write-read-repeat} writes its second argument to the output, then
|
|
|
1306 reads from the input into the register, and finally jumps. See the
|
|
|
1307 @code{write} and @code{read} statements for the semantics of the I/O
|
|
|
1308 operations for each type of argument.
|
|
|
1309
|
|
|
1310 @heading Other control statements:
|
|
|
1311
|
|
|
1312 The @dfn{call} statement, written @samp{(call @var{ccl-program-name})},
|
|
|
1313 executes a CCL program as a subroutine. It does not return a value to
|
|
|
1314 the caller, but can modify the register status.
|
|
|
1315
|
|
|
1316 The @dfn{end} statement, written @samp{(end)}, terminates the CCL
|
|
|
1317 program successfully, and returns to caller (which may be a CCL
|
|
|
1318 program). It does not alter the status of the registers.
|
|
|
1319
|
|
|
1320 @node CCL Expressions, Calling CCL, CCL Statements, CCL
|
|
|
1321 @comment Node, Next, Previous, Up
|
|
|
1322 @subsection CCL Expressions
|
|
|
1323
|
|
|
1324 CCL, unlike Lisp, uses infix expressions. The simplest CCL expressions
|
|
|
1325 consist of a single @var{operand}, either a register (one of @code{r0},
|
|
|
1326 ..., @code{r0}) or an integer. Complex expressions are lists of the
|
|
|
1327 form @code{( @var{expression} @var{operator} @var{operand} )}. Unlike
|
|
|
1328 C, assignments are not expressions.
|
|
|
1329
|
|
|
1330 In the following table, @var{X} is the target resister for a @dfn{set}.
|
|
|
1331 In subexpressions, this is implicitly @code{r7}. This means that
|
|
|
1332 @code{>8}, @code{//}, @code{de-sjis}, and @code{en-sjis} cannot be used
|
|
|
1333 freely in subexpressions, since they return parts of their values in
|
|
|
1334 @code{r7}. @var{Y} may be an expression, register, or integer, while
|
|
|
1335 @var{Z} must be a register or an integer.
|
|
|
1336
|
|
|
1337 @multitable @columnfractions .22 .14 .09 .55
|
|
|
1338 @item Name @tab Operator @tab Code @tab C-like Description
|
|
|
1339 @item CCL_PLUS @tab @code{+} @tab 0x00 @tab X = Y + Z
|
|
|
1340 @item CCL_MINUS @tab @code{-} @tab 0x01 @tab X = Y - Z
|
|
|
1341 @item CCL_MUL @tab @code{*} @tab 0x02 @tab X = Y * Z
|
|
|
1342 @item CCL_DIV @tab @code{/} @tab 0x03 @tab X = Y / Z
|
|
|
1343 @item CCL_MOD @tab @code{%} @tab 0x04 @tab X = Y % Z
|
|
|
1344 @item CCL_AND @tab @code{&} @tab 0x05 @tab X = Y & Z
|
|
|
1345 @item CCL_OR @tab @code{|} @tab 0x06 @tab X = Y | Z
|
|
|
1346 @item CCL_XOR @tab @code{^} @tab 0x07 @tab X = Y ^ Z
|
|
|
1347 @item CCL_LSH @tab @code{<<} @tab 0x08 @tab X = Y << Z
|
|
|
1348 @item CCL_RSH @tab @code{>>} @tab 0x09 @tab X = Y >> Z
|
|
|
1349 @item CCL_LSH8 @tab @code{<8} @tab 0x0A @tab X = (Y << 8) | Z
|
|
|
1350 @item CCL_RSH8 @tab @code{>8} @tab 0x0B @tab X = Y >> 8, r[7] = Y & 0xFF
|
|
|
1351 @item CCL_DIVMOD @tab @code{//} @tab 0x0C @tab X = Y / Z, r[7] = Y % Z
|
|
|
1352 @item CCL_LS @tab @code{<} @tab 0x10 @tab X = (X < Y)
|
|
|
1353 @item CCL_GT @tab @code{>} @tab 0x11 @tab X = (X > Y)
|
|
|
1354 @item CCL_EQ @tab @code{==} @tab 0x12 @tab X = (X == Y)
|
|
|
1355 @item CCL_LE @tab @code{<=} @tab 0x13 @tab X = (X <= Y)
|
|
|
1356 @item CCL_GE @tab @code{>=} @tab 0x14 @tab X = (X >= Y)
|
|
|
1357 @item CCL_NE @tab @code{!=} @tab 0x15 @tab X = (X != Y)
|
|
|
1358 @item CCL_ENCODE_SJIS @tab @code{en-sjis} @tab 0x16 @tab X = HIGHER_BYTE (SJIS (Y, Z))
|
|
|
1359 @item @tab @tab @tab r[7] = LOWER_BYTE (SJIS (Y, Z)
|
|
|
1360 @item CCL_DECODE_SJIS @tab @code{de-sjis} @tab 0x17 @tab X = HIGHER_BYTE (DE-SJIS (Y, Z))
|
|
|
1361 @item @tab @tab @tab r[7] = LOWER_BYTE (DE-SJIS (Y, Z))
|
|
|
1362 @end multitable
|
|
|
1363
|
|
|
1364 The CCL operators are as in C, with the addition of CCL_LSH8, CCL_RSH8,
|
|
|
1365 CCL_DIVMOD, CCL_ENCODE_SJIS, and CCL_DECODE_SJIS. The CCL_ENCODE_SJIS
|
|
|
1366 and CCL_DECODE_SJIS treat their first and second bytes as the high and
|
|
|
1367 low bytes of a two-byte character code. (SJIS stands for Shift JIS, an
|
|
|
1368 encoding of Japanese characters used by Microsoft. CCL_ENCODE_SJIS is a
|
|
|
1369 complicated transformation of the Japanese standard JIS encoding to
|
|
|
1370 Shift JIS. CCL_DECODE_SJIS is its inverse.) It is somewhat odd to
|
|
|
1371 represent the SJIS operations in infix form.
|
|
|
1372
|
|
|
1373 @node Calling CCL, CCL Examples, CCL Expressions, CCL
|
|
|
1374 @comment Node, Next, Previous, Up
|
|
|
1375 @subsection Calling CCL
|
|
|
1376
|
|
|
1377 CCL programs are called automatically during Emacs buffer I/O when the
|
|
|
1378 external representation has a coding system type of @code{shift-jis},
|
|
|
1379 @code{big5}, or @code{ccl}. The program is specified by the coding
|
|
|
1380 system (@pxref{Coding Systems}). You can also call CCL programs from
|
|
|
1381 other CCL programs, and from Lisp using these functions:
|
|
|
1382
|
|
|
1383 @defun ccl-execute ccl-program status
|
|
|
1384 Execute @var{ccl-program} with registers initialized by
|
|
0
|
1385 @var{status}. @var{ccl-program} is a vector of compiled CCL code
|
|
343
|
1386 created by @code{ccl-compile}. It is an error for the program to try to
|
|
|
1387 execute a CCL I/O command. @var{status} must be a vector of nine
|
|
0
|
1388 values, specifying the initial value for the R0, R1 .. R7 registers and
|
|
|
1389 for the instruction counter IC. A @code{nil} value for a register
|
|
|
1390 initializer causes the register to be set to 0. A @code{nil} value for
|
|
|
1391 the IC initializer causes execution to start at the beginning of the
|
|
|
1392 program. When the program is done, @var{status} is modified (by
|
|
|
1393 side-effect) to contain the ending values for the corresponding
|
|
343
|
1394 registers and IC.
|
|
0
|
1395 @end defun
|
|
|
1396
|
|
343
|
1397 @defun ccl-execute-on-string ccl-program status str &optional continue
|
|
|
1398 Execute @var{ccl-program} with initial @var{status} on
|
|
0
|
1399 @var{string}. @var{ccl-program} is a vector of compiled CCL code
|
|
|
1400 created by @code{ccl-compile}. @var{status} must be a vector of nine
|
|
|
1401 values, specifying the initial value for the R0, R1 .. R7 registers and
|
|
|
1402 for the instruction counter IC. A @code{nil} value for a register
|
|
|
1403 initializer causes the register to be set to 0. A @code{nil} value for
|
|
|
1404 the IC initializer causes execution to start at the beginning of the
|
|
343
|
1405 program. An optional fourth argument @var{continue}, if non-nil, causes
|
|
|
1406 the IC to
|
|
|
1407 remain on the unsatisfied read operation if the program terminates due
|
|
|
1408 to exhaustion of the input buffer. Otherwise the IC is set to the end
|
|
|
1409 of the program. When the program is done, @var{status} is modified (by
|
|
0
|
1410 side-effect) to contain the ending values for the corresponding
|
|
|
1411 registers and IC. Returns the resulting string.
|
|
|
1412 @end defun
|
|
|
1413
|
|
343
|
1414 To call a CCL program from another CCL program, it must first be
|
|
|
1415 registered:
|
|
|
1416
|
|
|
1417 @defun register-ccl-program name ccl-program
|
|
|
1418 Register @var{name} for CCL program @var{program} in
|
|
|
1419 @code{ccl-program-table}. @var{program} should be the compiled form of
|
|
|
1420 a CCL program, or nil. Return index number of the registered CCL
|
|
|
1421 program.
|
|
0
|
1422 @end defun
|
|
|
1423
|
|
343
|
1424 Information about the processor time used by the CCL interpreter can be
|
|
|
1425 obtained using these functions:
|
|
|
1426
|
|
0
|
1427 @defun ccl-elapsed-time
|
|
343
|
1428 Returns the elapsed processor time of the CCL interpreter as cons of
|
|
|
1429 user and system time, as
|
|
|
1430 floating point numbers measured in seconds. If only one
|
|
0
|
1431 overall value can be determined, the return value will be a cons of that
|
|
|
1432 value and 0.
|
|
|
1433 @end defun
|
|
|
1434
|
|
343
|
1435 @defun ccl-reset-elapsed-time
|
|
|
1436 Resets the CCL interpreter's internal elapsed time registers.
|
|
|
1437 @end defun
|
|
|
1438
|
|
|
1439 @node CCL Examples, , Calling CCL, CCL
|
|
|
1440 @comment Node, Next, Previous, Up
|
|
|
1441 @subsection CCL Examples
|
|
|
1442
|
|
|
1443 This section is not yet written.
|
|
|
1444
|
|
|
1445 @node Category Tables, , CCL, MULE
|
|
0
|
1446 @section Category Tables
|
|
|
1447
|
|
|
1448 A category table is a type of char table used for keeping track of
|
|
|
1449 categories. Categories are used for classifying characters for use in
|
|
|
1450 regexps -- you can refer to a category rather than having to use a
|
|
|
1451 complicated [] expression (and category lookups are significantly
|
|
|
1452 faster).
|
|
|
1453
|
|
|
1454 There are 95 different categories available, one for each printable
|
|
|
1455 character (including space) in the ASCII charset. Each category is
|
|
|
1456 designated by one such character, called a @dfn{category designator}.
|
|
|
1457 They are specified in a regexp using the syntax @samp{\cX}, where X is a
|
|
|
1458 category designator. (This is not yet implemented.)
|
|
|
1459
|
|
|
1460 A category table specifies, for each character, the categories that
|
|
|
1461 the character is in. Note that a character can be in more than one
|
|
|
1462 category. More specifically, a category table maps from a character to
|
|
|
1463 either the value @code{nil} (meaning the character is in no categories)
|
|
|
1464 or a 95-element bit vector, specifying for each of the 95 categories
|
|
|
1465 whether the character is in that category.
|
|
|
1466
|
|
|
1467 Special Lisp functions are provided that abstract this, so you do not
|
|
|
1468 have to directly manipulate bit vectors.
|
|
|
1469
|
|
|
1470 @defun category-table-p obj
|
|
|
1471 This function returns @code{t} if @var{arg} is a category table.
|
|
|
1472 @end defun
|
|
|
1473
|
|
|
1474 @defun category-table &optional buffer
|
|
|
1475 This function returns the current category table. This is the one
|
|
|
1476 specified by the current buffer, or by @var{buffer} if it is
|
|
|
1477 non-@code{nil}.
|
|
|
1478 @end defun
|
|
|
1479
|
|
|
1480 @defun standard-category-table
|
|
|
1481 This function returns the standard category table. This is the one used
|
|
|
1482 for new buffers.
|
|
|
1483 @end defun
|
|
|
1484
|
|
|
1485 @defun copy-category-table &optional table
|
|
|
1486 This function constructs a new category table and return it. It is a
|
|
|
1487 copy of the @var{table}, which defaults to the standard category table.
|
|
|
1488 @end defun
|
|
|
1489
|
|
|
1490 @defun set-category-table table &optional buffer
|
|
|
1491 This function selects a new category table for @var{buffer}. One
|
|
|
1492 argument, a category table. @var{buffer} defaults to the current buffer
|
|
|
1493 if omitted.
|
|
|
1494 @end defun
|
|
|
1495
|
|
|
1496 @defun category-designator-p obj
|
|
|
1497 This function returns @code{t} if @var{arg} is a category designator (a
|
|
|
1498 char in the range @samp{' '} to @samp{'~'}).
|
|
|
1499 @end defun
|
|
|
1500
|
|
|
1501 @defun category-table-value-p obj
|
|
|
1502 This function returns @code{t} if @var{arg} is a category table value.
|
|
|
1503 Valid values are @code{nil} or a bit vector of size 95.
|
|
|
1504 @end defun
|
|
|
1505
|
