Added optional Lua lexer support.

This support is disabled by default and must be enabled via compile-time option.

1 files changed, 58 insertions, 0 deletions

diff --git a/lexlua/latex.lua b/lexlua/latex.lua
new file mode 100644
index 000000000..a1a0f6eb4
--- /dev/null
+++ b/lexlua/latex.lua
@@ -0,0 +1,58 @@
+-- Copyright 2006-2018 Mitchell mitchell.att.foicica.com. See License.txt.
+-- Latex LPeg lexer.
+-- Modified by Brian Schott.
+-- Modified by Robert Gieseke.
+
+local lexer = require('lexer')
+local token, word_match = lexer.token, lexer.word_match
+local P, R, S = lpeg.P, lpeg.R, lpeg.S
+
+local lex = lexer.new('latex')
+
+-- Whitespace.
+lex:add_rule('whitespace', token(lexer.WHITESPACE, lexer.space^1))
+
+-- Comments.
+local line_comment = '%' * lexer.nonnewline^0
+local block_comment = '\\begin' * P(' ')^0 * '{comment}' *
+                      (lexer.any - '\\end' * P(' ')^0 * '{comment}')^0 *
+                      P('\\end' * P(' ')^0 * '{comment}')^-1
+lex:add_rule('comment', token(lexer.COMMENT, line_comment + block_comment))
+
+-- Math environments.
+local math_word = word_match[[
+  align displaymath eqnarray equation gather math multline
+]]
+local math_begin_end = (P('begin') + P('end')) * P(' ')^0 *
+                       '{' * math_word * P('*')^-1 * '}'
+lex:add_rule('math', token('math', '$' + '\\' * (S('[]()') + math_begin_end)))
+lex:add_style('math', lexer.STYLE_FUNCTION)
+
+-- LaTeX environments.
+lex:add_rule('environment', token('environment', '\\' *
+                                                 (P('begin') + P('end')) *
+                                                 P(' ')^0 * '{' * lexer.word *
+                                                 P('*')^-1 * '}'))
+lex:add_style('environment', lexer.STYLE_KEYWORD)
+
+-- Sections.
+lex:add_rule('section', token('section', '\\' * word_match[[
+  part chapter section subsection subsubsection paragraph subparagraph
+]] * P('*')^-1))
+lex:add_style('section', lexer.STYLE_CLASS)
+
+-- Commands.
+lex:add_rule('command', token('command', '\\' *
+                                         (lexer.alpha^1 + S('#$&~_^%{}'))))
+lex:add_style('command', lexer.STYLE_KEYWORD)
+
+-- Operators.
+lex:add_rule('operator', token(lexer.OPERATOR, S('&#{}[]')))
+
+-- Fold points.
+lex:add_fold_point(lexer.COMMENT, '\\begin', '\\end')
+lex:add_fold_point(lexer.COMMENT, '%', lexer.fold_line_comments('%'))
+lex:add_fold_point('environment', '\\begin', '\\end')
+lex:add_fold_point(lexer.OPERATOR, '{', '}')
+
+return lex