Added optional Lua lexer support.

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

1 files changed, 34 insertions, 0 deletions

diff --git a/lexlua/tex.lua b/lexlua/tex.lua
new file mode 100644
index 000000000..185c543ee
--- /dev/null
+++ b/lexlua/tex.lua
@@ -0,0 +1,34 @@
+-- Copyright 2006-2018 Mitchell mitchell.att.foicica.com. See License.txt.
+-- Plain TeX LPeg lexer.
+-- 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('tex')
+
+-- Whitespace.
+lex:add_rule('whitespace', token(lexer.WHITESPACE, lexer.space^1))
+
+-- Comments.
+lex:add_rule('comment', token(lexer.COMMENT, '%' * lexer.nonnewline^0))
+
+-- TeX environments.
+lex:add_rule('environment', token('environment', '\\' * (P('begin') + 'end') *
+                                                 lexer.word))
+lex:add_style('environment', lexer.STYLE_KEYWORD)
+
+-- Commands.
+lex:add_rule('command', token(lexer.KEYWORD, '\\' *
+                                             (lexer.alpha^1 + S('#$&~_^%{}'))))
+
+-- Operators.
+lex:add_rule('operator', token(lexer.OPERATOR, S('$&#{}[]')))
+
+-- Fold points.
+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