Added optional Lua lexer support.

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

1 files changed, 101 insertions, 0 deletions

diff --git a/lexlua/wsf.lua b/lexlua/wsf.lua
new file mode 100644
index 000000000..123d3b543
--- /dev/null
+++ b/lexlua/wsf.lua
@@ -0,0 +1,101 @@
+-- Copyright 2006-2018 Mitchell mitchell.att.foicica.com. See License.txt.
+-- WSF LPeg lexer (based on XML).
+-- Contributed by Jeff Stone.
+
+local lexer = require('lexer')
+local token, word_match = lexer.token, lexer.word_match
+local P, R, S, V = lpeg.P, lpeg.R, lpeg.S, lpeg.V
+
+local lex = lexer.new('wsf')
+
+-- Whitespace.
+local ws = token(lexer.WHITESPACE, lexer.space^1)
+lex:add_rule('whitespace', ws)
+
+-- Comments.
+lex:add_rule('comment', token(lexer.COMMENT, '<!--' * (lexer.any - '-->')^0 *
+                                             P('-->')^-1))
+
+local alpha = R('az', 'AZ', '\127\255')
+local word_char = lexer.alnum + S('_-:.??')
+local identifier = (alpha + S('_-:.??')) * word_char^0
+
+-- Elements.
+local element = token('element', '<' * P('/')^-1 * identifier)
+lex:add_rule('element', element)
+lex:add_style('element', lexer.STYLE_KEYWORD)
+
+-- Closing tags.
+local tag_close = token('element', P('/')^-1 * '>')
+lex:add_rule('tag_close', tag_close)
+
+-- Attributes.
+local attribute = token('attribute', identifier) * #(lexer.space^0 * '=')
+lex:add_rule('attribute', attribute)
+lex:add_style('attribute', lexer.STYLE_TYPE)
+
+local in_tag = P(function(input, index)
+  local before = input:sub(1, index - 1)
+  local s, e = before:find('<[^>]-$'), before:find('>[^<]-$')
+  if s and e then return s > e and index or nil end
+  if s then return index end
+  return input:find('^[^<]->', index) and index or nil
+end)
+
+-- Equals.
+local equals = token(lexer.OPERATOR, '=') * in_tag
+lex:add_rule('equals', equals)
+
+-- Strings.
+local string = #S('\'"') * lexer.last_char_includes('=') *
+               token(lexer.STRING, lexer.delimited_range("'", false, true) +
+                                   lexer.delimited_range('"', false, true))
+lex:add_rule('string', string)
+
+-- Numbers.
+lex:add_rule('number', #lexer.digit * lexer.last_char_includes('=') *
+                       token(lexer.NUMBER, lexer.digit^1 * P('%')^-1) * in_tag)
+
+-- Entities.
+lex:add_rule('entity', token('entity', '&' * word_match[[
+  lt gt amp apos quot
+]] * ';'))
+lex:add_style('entity', lexer.STYLE_OPERATOR)
+
+-- Fold points.
+local function disambiguate_lt(text, pos, line, s)
+  return not line:find('^</', s) and 1 or -1
+end
+lex:add_fold_point('element', '<', disambiguate_lt)
+lex:add_fold_point('element', '/>', -1)
+lex:add_fold_point(lexer.COMMENT, '<!--', '-->')
+
+-- Finally, add JavaScript and VBScript as embedded languages
+
+-- Tags that start embedded languages.
+local embed_start_tag = element *
+                        (ws^1 * attribute * ws^0 * equals * ws^0 * string)^0 *
+                        ws^0 * tag_close
+local embed_end_tag = element * tag_close
+
+-- Embedded JavaScript.
+local js = lexer.load('javascript')
+local js_start_rule = #(P('<script') * (P(function(input, index)
+  if input:find('^%s+language%s*=%s*(["\'])[jJ][ava]*[sS]cript%1', index) then
+    return index
+  end
+end) + '>')) * embed_start_tag -- <script language="javascript">
+local js_end_rule = #('</script' * ws^0 * '>') * embed_end_tag -- </script>
+lex:embed(js, js_start_rule, js_end_rule)
+
+-- Embedded VBScript.
+local vbs = lexer.load('vbscript')
+local vbs_start_rule = #(P('<script') * (P(function(input, index)
+  if input:find('^%s+language%s*=%s*(["\'])[vV][bB][sS]cript%1', index) then
+    return index
+  end
+end) + '>')) * embed_start_tag -- <script language="vbscript">
+local vbs_end_rule = #('</script' * ws^0 * '>') * embed_end_tag -- </script>
+lex:embed(vbs, vbs_start_rule, vbs_end_rule)
+
+return lex