liblouis: Miscellaneous Opcodes
1
1 2.13 Miscellaneous Opcodes
1 ==========================
1
1 'include filename'
1 Read the file indicated by 'filename' and incorporate or include
1 its entries into the table. Included files can include other
1 files, which can include other files, etc. For an example, see
1 what files are included by the entry include 'en-us-g1.ctb' in the
1 table 'en-us-g2.ctb'. If the included file is not in the same
1 directory as the main table, use a full path name for filename.
1
1 'locale characters'
1 Not implemented, but recognized and ignored for backward
1 compatibility.
1
1 'undefined dots'
1 If this opcode is used in a table any characters which have not
1 been defined in the table but are encountered in the text will be
1 replaced by the dot pattern. If this opcode is not used, any
1 undefined characters are replaced by ''\xhhhh'', where the h's are
1 hexadecimal digits.
1
1 'display character dots'
1 Associates dot patterns with the characters which will be sent to a
1 braille embosser, display or screen font. The character must be in
1 the range 0-255 and the dots must specify a single cell. Here are
1 some examples:
1
1 # When the character a is sent to the embosser or display,
1 # it will produce a dot 1.
1 display a 1
1
1 # When the character L is sent to the display or embosser
1 # it will produce dots 1-2-3.
1 display L 123
1
1 The 'display' opcode is optional. It is used when the embosser or
1 display has a different mapping of characters to dot patterns than
1 that given in ⇒Character-Definition Opcodes. If used,
1 display entries must proceed character-definition entries.
1
1 A possible use case would be to define display opcodes so that the
1 result is Unicode braille for use on a display and a second set of
1 display opcodes (in a different file) to produce plain ASCII
1 braille for use with an embosser.
1
1 'multind dots opcode opcode ...'
1 The 'multind' opcode tells the back-translator that a sequence of
1 braille cells represents more than one braille indicator. For
1 example, in 'en-us-g1.ctb' we have 'multind 56-6 letsign capsign'.
1 The back-translator can generally handle single braille indicators,
1 but it cannot apply them when they immediately follow each other.
1 It recognizes the letter sign if it is followed by a letter and
1 takes appropriate action. It also recognizes the capital sign if
1 it is followed by a letter. But when there is a letter sign
1 followed by a capital sign it fails to recognize the letter sign
1 unless the sequence has been defined with 'multind'. A 'multind'
1 entry may not contain a comment because liblouis would attempt to
1 interpret it as an opcode.
1