Added optional Lua lexer support.

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

1 files changed, 49 insertions, 0 deletions

diff --git a/lexlua/tcl.lua b/lexlua/tcl.lua
new file mode 100644
index 000000000..5ac96f85f
--- /dev/null
+++ b/lexlua/tcl.lua
@@ -0,0 +1,49 @@
+-- Copyright 2014-2018 Joshua Krämer. See License.txt.
+-- Tcl LPeg lexer.
+-- This lexer follows the TCL dodekalogue (http://wiki.tcl.tk/10259).
+-- It is based on the previous lexer by Mitchell.
+
+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('tcl')
+
+-- Whitespace.
+lex:add_rule('whitespace', token(lexer.WHITESPACE, lexer.space^1))
+
+-- Comment.
+lex:add_rule('comment', token(lexer.COMMENT, '#' * P(function(input, index)
+  local i = index - 2
+  while i > 0 and input:find('^[ \t]', i) do i = i - 1 end
+  if i < 1 or input:find('^[\r\n;]', i) then return index end
+end) * lexer.nonnewline^0))
+
+-- Separator (semicolon).
+lex:add_rule('separator', token(lexer.CLASS, P(';')))
+
+-- Argument expander.
+lex:add_rule('expander', token(lexer.LABEL, P('{*}')))
+
+-- Delimiters.
+lex:add_rule('braces', token(lexer.KEYWORD, S('{}')))
+lex:add_rule('quotes', token(lexer.FUNCTION, '"'))
+lex:add_rule('brackets', token(lexer.VARIABLE, S('[]')))
+
+-- Variable substitution.
+lex:add_rule('variable', token(lexer.STRING, '$' *
+                                             (lexer.alnum + '_' + P(':')^2)^0))
+
+-- Backslash substitution.
+lex:add_rule('backslash', token(lexer.TYPE,
+                                '\\' * (lexer.digit * lexer.digit^-2 +
+                                        'x' * lexer.xdigit^1 +
+                                        'u' * lexer.xdigit * lexer.xdigit^-3 +
+                                        'U' * lexer.xdigit * lexer.xdigit^-7 +
+                                        1)))
+
+-- Fold points.
+lex:add_fold_point(lexer.KEYWORD, '{', '}')
+lex:add_fold_point(lexer.COMMENT, '#', lexer.fold_line_comments('#'))
+
+return lex