Added optional Lua lexer support.

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

1 files changed, 47 insertions, 0 deletions

diff --git a/lexlua/context.lua b/lexlua/context.lua
new file mode 100644
index 000000000..5b3510671
--- /dev/null
+++ b/lexlua/context.lua
@@ -0,0 +1,47 @@
+-- Copyright 2006-2018 Robert Gieseke. See License.txt.
+-- ConTeXt LPeg lexer.
+
+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('context')
+
+-- Whitespace.
+lex:add_rule('whitespace', token(lexer.WHITESPACE, lexer.space^1))
+
+-- Comments.
+lex:add_rule('comment', token(lexer.COMMENT, '%' * lexer.nonnewline^0))
+
+-- ConTeXt environments.
+local environment = token('environment', '\\' * (P('start') + 'stop') *
+                                         lexer.word)
+lex:add_rule('environment', environment)
+lex:add_style('environment', lexer.STYLE_KEYWORD)
+
+-- Sections.
+lex:add_rule('section', token('section', '\\' * word_match[[
+  chapter part section subject subsection subsubject subsubsection subsubsubject
+  title
+]]))
+lex:add_style('section', lexer.STYLE_CLASS)
+
+-- 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('environment', '\\start', '\\stop')
+lex:add_fold_point(lexer.OPERATOR, '{', '}')
+lex:add_fold_point(lexer.COMMENT, '%', lexer.fold_line_comments('%'))
+
+-- Embedded Lua.
+local luatex = lexer.load('lua')
+local luatex_start_rule = #P('\\startluacode') * environment
+local luatex_end_rule = #P('\\stopluacode') * environment
+lex:embed(luatex, luatex_start_rule, luatex_end_rule)
+
+return lex