Added optional Lua lexer support.

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

1 files changed, 149 insertions, 0 deletions

diff --git a/lexlua/html.lua b/lexlua/html.lua
new file mode 100644
index 000000000..8c8d999c7
--- /dev/null
+++ b/lexlua/html.lua
@@ -0,0 +1,149 @@
+-- Copyright 2006-2018 Mitchell mitchell.att.foicica.com. See License.txt.
+-- HTML LPeg lexer.
+
+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('html')
+
+-- 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))
+
+-- Doctype.
+lex:add_rule('doctype', token('doctype', '<!' * word_match([[doctype]], true) *
+                                         (lexer.any - '>')^1 * '>'))
+lex:add_style('doctype', lexer.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))
+local unknown_element = token('unknown_element', '<' * P('/')^-1 * lexer.word)
+local element = known_element + unknown_element
+lex:add_rule('element', element)
+lex:add_style('element', lexer.STYLE_KEYWORD)
+lex:add_style('unknown_element', lexer.STYLE_KEYWORD..',italics')
+
+-- Closing tags.
+local tag_close = token('element', P('/')^-1 * '>')
+lex: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-') * (lexer.alnum + '-')^1))
+local unknown_attribute = token('unknown_attribute', lexer.word)
+local attribute = (known_attribute + unknown_attribute) * #(lexer.space^0 * '=')
+lex:add_rule('attribute', attribute)
+lex:add_style('attribute', lexer.STYLE_TYPE)
+lex:add_style('unknown_attribute', lexer.STYLE_TYPE..',italics')
+
+-- 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(lexer.OPERATOR, '=') --* in_tag
+--lex:add_rule('equals', equals)
+
+-- Strings.
+local string = #S('\'"') * lexer.last_char_includes('=') *
+               token(lexer.STRING, lexer.delimited_range("'") +
+                                   lexer.delimited_range('"'))
+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', '&' * (lexer.any - lexer.space - ';')^1 *
+                                       ';'))
+lex:add_style('entity', lexer.STYLE_COMMENT)
+
+-- 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('unknown_element', '<', disambiguate_lt)
+lex:add_fold_point('unknown_element', '/>', -1)
+lex:add_fold_point(lexer.COMMENT, '<!--', '-->')
+
+-- Tags that start embedded languages.
+-- Export these patterns for proxy lexers (e.g. ASP) that need them.
+lex.embed_start_tag = element *
+                      (ws * attribute * ws^-1 * equals * ws^-1 * string)^0 *
+                      ws^-1 * tag_close
+lex.embed_end_tag = element * tag_close
+
+-- Embedded CSS (<style type="text/css"> ... </style>).
+local css = lexer.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))) * lex.embed_start_tag
+local css_end_rule = #('</' * style_element * ws^-1 * '>') * lex.embed_end_tag
+lex:embed(css, css_start_rule, css_end_rule)
+
+-- Embedded JavaScript (<script type="text/javascript"> ... </script>).
+local js = lexer.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))) * lex.embed_start_tag
+local js_end_rule = #('</' * script_element * ws^-1 * '>') * lex.embed_end_tag
+local js_line_comment = '//' * (lexer.nonnewline_esc - js_end_rule)^0
+local js_block_comment = '/*' * (lexer.any - '*/' - js_end_rule)^0 * P('*/')^-1
+js:modify_rule('comment', token(lexer.COMMENT, js_line_comment +
+                                               js_block_comment))
+lex:embed(js, js_start_rule, js_end_rule)
+
+-- Embedded CoffeeScript (<script type="text/coffeescript"> ... </script>).
+local cs = lexer.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)) * lex.embed_start_tag
+local cs_end_rule = #('</' * script_element * ws^-1 * '>') * lex.embed_end_tag
+lex:embed(cs, cs_start_rule, cs_end_rule)
+
+return lex