vis

a vi-like editor based on Plan 9's structural regular expressions
latex.lua

(1504B)
      1 -- Copyright 2006-2025 Mitchell. See LICENSE.
      2 -- Latex LPeg lexer.
      3 -- Modified by Brian Schott.
      4 -- Modified by Robert Gieseke.
      5 
      6 local lexer = lexer
      7 local word_match = lexer.word_match
      8 local P, S = lpeg.P, lpeg.S
      9 
     10 local lex = lexer.new(...)
     11 
     12 -- Comments.
     13 local line_comment = lexer.to_eol('%')
     14 local block_comment = lexer.range('\\begin' * P(' ')^0 * '{comment}',
     15 	'\\end' * P(' ')^0 * '{comment}')
     16 lex:add_rule('comment', lex:tag(lexer.COMMENT, line_comment + block_comment))
     17 
     18 -- Math environments.
     19 local math_word = word_match('align displaymath eqnarray equation gather math multline')
     20 local math_begin_end = (P('begin') + P('end')) * P(' ')^0 * '{' * math_word * P('*')^-1 * '}'
     21 lex:add_rule('math', lex:tag('environment.math', '$' + '\\' * (S('[]()') + math_begin_end)))
     22 
     23 -- LaTeX environments.
     24 lex:add_rule('environment', lex:tag('environment', '\\' * (P('begin') + 'end') * P(' ')^0 * '{' *
     25 	lexer.word * P('*')^-1 * '}'))
     26 
     27 -- Sections.
     28 lex:add_rule('section', lex:tag('command.section', '\\' *
     29 	word_match('part chapter section subsection subsubsection paragraph subparagraph') * P('*')^-1))
     30 
     31 -- Commands.
     32 lex:add_rule('command', lex:tag('command', '\\' * (lexer.alpha^1 + S('#$&~_^%{}\\'))))
     33 
     34 -- Operators.
     35 lex:add_rule('operator', lex:tag(lexer.OPERATOR, S('&#{}[]')))
     36 
     37 -- Fold points.
     38 lex:add_fold_point(lexer.COMMENT, '\\begin', '\\end')
     39 lex:add_fold_point('environment', '\\begin', '\\end')
     40 lex:add_fold_point(lexer.OPERATOR, '{', '}')
     41 
     42 lexer.property['scintillua.comment'] = '%'
     43 
     44 return lex