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