Added optional Lua lexer support.

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

1 files changed, 51 insertions, 0 deletions

diff --git a/lexlua/io_lang.lua b/lexlua/io_lang.lua
new file mode 100644
index 000000000..28772bec4
--- /dev/null
+++ b/lexlua/io_lang.lua
@@ -0,0 +1,51 @@
+-- Copyright 2006-2018 Mitchell mitchell.att.foicica.com. See License.txt.
+-- Io 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('io_lang')
+
+-- Whitespace.
+lex:add_rule('whitespace', token(lexer.WHITESPACE, lexer.space^1))
+
+-- Keywords.
+lex:add_rule('keyword', token(lexer.KEYWORD, word_match[[
+  block method while foreach if else do super self clone proto setSlot hasSlot
+  type write print forward
+]]))
+
+-- Types.
+lex:add_rule('type', token(lexer.TYPE, word_match[[
+  Block Buffer CFunction Date Duration File Future LinkedList List Map Message
+  Nil Nop Number Object String WeakLink
+]]))
+
+-- Identifiers.
+lex:add_rule('identifier', token(lexer.IDENTIFIER, lexer.word))
+
+-- Strings.
+local sq_str = lexer.delimited_range("'")
+local dq_str = lexer.delimited_range('"')
+local tq_str = '"""' * (lexer.any - '"""')^0 * P('"""')^-1
+lex:add_rule('string', token(lexer.STRING, tq_str + sq_str + dq_str))
+
+-- Comments.
+local line_comment = (P('#') + '//') * lexer.nonnewline^0
+local block_comment = '/*' * (lexer.any - '*/')^0 * P('*/')^-1
+lex:add_rule('comment', token(lexer.COMMENT, line_comment + block_comment))
+
+-- Numbers.
+lex:add_rule('number', token(lexer.NUMBER, lexer.float + lexer.integer))
+
+-- Operators.
+lex:add_rule('operator', token(lexer.OPERATOR,
+                               S('`~@$%^&*-+/=\\<>?.,:;()[]{}')))
+
+-- Fold points.
+lex:add_fold_point(lexer.OPERATOR, '(', ')')
+lex:add_fold_point(lexer.COMMENT, '/*', '*/')
+lex:add_fold_point(lexer.COMMENT, '//', lexer.fold_line_comments('//'))
+
+return lex