Added optional Lua lexer support.

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

1 files changed, 147 insertions, 0 deletions

diff --git a/lexlua/html2.lua b/lexlua/html2.lua
new file mode 100644
index 000000000..ad1bd9c87
--- /dev/null
+++ b/lexlua/html2.lua
@@ -0,0 +1,147 @@
+-- Copyright 2006-2018 Mitchell mitchell.att.foicica.com. See License.txt.
+-- HTML LPeg lexer.
+
+local l = require('lexer')
+local token, word_match = l.token, l.word_match
+local P, R, S, V = lpeg.P, lpeg.R, lpeg.S, lpeg.V
+
+local lexer = l.new('html')
+
+-- Whitespace.
+local ws = token(l.WHITESPACE, l.space^1)
+lexer:add_rule('whitespace', ws)
+
+-- Comments.
+lexer:add_rule('comment',
+               token(l.COMMENT, '<!--' * (l.any - '-->')^0 * P('-->')^-1))
+
+-- Doctype.
+lexer:add_rule('doctype', token('doctype', '<!' * word_match('doctype', true) *
+                                           (l.any - '>')^1 * '>'))
+lexer:add_style('doctype', l.STYLE_COMMENT)
+
+-- Elements.
+local known_element = token('element', '<' * P('/')^-1 * word_match([[
+  a abbr address area article aside audio b base bdi bdo blockquote body
+  br button canvas caption cite code col colgroup content data datalist dd
+  decorator del details dfn div dl dt element em embed fieldset figcaption
+  figure footer form h1 h2 h3 h4 h5 h6 head header hr html i iframe img input
+  ins kbd keygen label legend li link main map mark menu menuitem meta meter
+  nav noscript object ol optgroup option output p param pre progress q rp rt
+  ruby s samp script section select shadow small source spacer span strong
+  style sub summary sup table tbody td template textarea tfoot th thead time
+  title tr track u ul var video wbr
+]], true))
+lexer:add_style('element', l.STYLE_KEYWORD)
+local unknown_element = token('unknown_element', '<' * P('/')^-1 * l.word)
+lexer:add_style('unknown_element', l.STYLE_KEYWORD..',italics')
+local element = known_element + unknown_element
+lexer:add_rule('element', element)
+
+-- Closing tags.
+local tag_close = token('element', P('/')^-1 * '>')
+lexer:add_rule('tag_close', tag_close)
+
+-- Attributes.
+local known_attribute = token('attribute', word_match([[
+  accept accept-charset accesskey action align alt async autocomplete autofocus
+  autoplay bgcolor border buffered challenge charset checked cite class code
+  codebase color cols colspan content contenteditable contextmenu controls
+  coords data data- datetime default defer dir dirname disabled download
+  draggable dropzone enctype for form headers height hidden high href hreflang
+  http-equiv icon id ismap itemprop keytype kind label lang language list
+  loop low manifest max maxlength media method min multiple name novalidate
+  open optimum pattern ping placeholder poster preload pubdate radiogroup
+  readonly rel required reversed role rows rowspan sandbox scope scoped
+  seamless selected shape size sizes span spellcheck src srcdoc srclang
+  start step style summary tabindex target title type usemap value width wrap
+]], true) + ((P('data-') + 'aria-') * (l.alnum + '-')^1))
+lexer:add_style('attribute', l.STYLE_TYPE)
+local unknown_attribute = token('unknown_attribute', l.word)
+lexer:add_style('unknown_attribute', l.STYLE_TYPE..',italics')
+local attribute = (known_attribute + unknown_attribute) * #(l.space^0 * '=')
+lexer:add_rule('attribute', attribute)
+
+-- TODO: performance is terrible on large files.
+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(l.OPERATOR, '=') --* in_tag
+--lexer:add_rule('equals', equals)
+
+-- Strings.
+local sq_str = l.delimited_range("'")
+local dq_str = l.delimited_range('"')
+local string = #S('\'"') * l.last_char_includes('=') *
+               token(l.STRING, sq_str + dq_str)
+lexer:add_rule('string', string)
+
+-- Numbers.
+lexer:add_rule('number', #l.digit * l.last_char_includes('=') *
+                         token(l.NUMBER, l.digit^1 * P('%')^-1)) --* in_tag)
+
+-- Entities.
+lexer:add_rule('entity', token('entity', '&' * (l.any - l.space - ';')^1 * ';'))
+lexer:add_style('entity', l.STYLE_COMMENT)
+
+-- Fold points.
+lexer:add_fold_point('element', '<', '</')
+lexer:add_fold_point('element', '<', '/>')
+lexer:add_fold_point('unknown_element', '<', '</')
+lexer:add_fold_point('unknown_element', '<', '/>')
+lexer:add_fold_point(l.COMMENT, '<!--', '-->')
+
+-- Tags that start embedded languages.
+lexer.embed_start_tag = element *
+                        (ws * attribute * ws^-1 * equals * ws^-1 * string)^0 *
+                        ws^-1 * tag_close
+lexer.embed_end_tag = element * tag_close
+
+-- Embedded CSS.
+local css = l.load('css')
+local style_element = word_match('style', true)
+local css_start_rule = #(P('<') * style_element *
+                         ('>' + P(function(input, index)
+  if input:find('^%s+type%s*=%s*(["\'])text/css%1', index) then
+    return index
+  end
+end))) * lexer.embed_start_tag -- <style type="text/css">
+local css_end_rule = #('</' * style_element * ws^-1 * '>') *
+                     lexer.embed_end_tag -- </style>
+lexer:embed(css, css_start_rule, css_end_rule)
+
+-- Embedded JavaScript.
+local js = l.load('javascript')
+local script_element = word_match('script', true)
+local js_start_rule = #(P('<') * script_element *
+                        ('>' + P(function(input, index)
+  if input:find('^%s+type%s*=%s*(["\'])text/javascript%1', index) then
+    return index
+  end
+end))) * lexer.embed_start_tag -- <script type="text/javascript">
+local js_end_rule = #('</' * script_element * ws^-1 * '>') *
+                    lexer.embed_end_tag -- </script>
+local js_line_comment = '//' * (l.nonnewline_esc - js_end_rule)^0
+local js_block_comment = '/*' * (l.any - '*/' - js_end_rule)^0 * P('*/')^-1
+js:modify_rule('comment', token(l.COMMENT, js_line_comment + js_block_comment))
+lexer:embed(js, js_start_rule, js_end_rule)
+
+-- Embedded CoffeeScript.
+local cs = l.load('coffeescript')
+local script_element = word_match('script', true)
+local cs_start_rule = #(P('<') * script_element * P(function(input, index)
+  if input:find('^[^>]+type%s*=%s*(["\'])text/coffeescript%1', index) then
+    return index
+  end
+end)) * lexer.embed_start_tag -- <script type="text/coffeescript">
+local cs_end_rule = #('</' * script_element * ws^-1 * '>') *
+                    lexer.embed_end_tag -- </script>
+lexer:embed(cs, cs_start_rule, cs_end_rule)
+
+return lexer