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Diffstat (limited to 'lexlua/markdown.lua')
| -rw-r--r-- | lexlua/markdown.lua | 102 |
1 files changed, 102 insertions, 0 deletions
diff --git a/lexlua/markdown.lua b/lexlua/markdown.lua new file mode 100644 index 000000000..2622a11d7 --- /dev/null +++ b/lexlua/markdown.lua @@ -0,0 +1,102 @@ +-- Copyright 2006-2018 Mitchell mitchell.att.foicica.com. See License.txt. +-- Markdown LPeg lexer. + +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('markdown') + +-- Block elements. +lex:add_rule('header', + token('h6', lexer.starts_line('######') * lexer.nonnewline^0) + + token('h5', lexer.starts_line('#####') * lexer.nonnewline^0) + + token('h4', lexer.starts_line('####') * lexer.nonnewline^0) + + token('h3', lexer.starts_line('###') * lexer.nonnewline^0) + + token('h2', lexer.starts_line('##') * lexer.nonnewline^0) + + token('h1', lexer.starts_line('#') * lexer.nonnewline^0)) +local font_size = lexer.property_int['fontsize'] > 0 and + lexer.property_int['fontsize'] or 10 +local hstyle = 'fore:$(color.red)' +lex:add_style('h6', hstyle) +lex:add_style('h5', hstyle..',size:'..(font_size + 1)) +lex:add_style('h4', hstyle..',size:'..(font_size + 2)) +lex:add_style('h3', hstyle..',size:'..(font_size + 3)) +lex:add_style('h2', hstyle..',size:'..(font_size + 4)) +lex:add_style('h1', hstyle..',size:'..(font_size + 5)) + +lex:add_rule('blockquote', + token(lexer.STRING, + lpeg.Cmt(lexer.starts_line(S(' \t')^0 * '>'), + function(input, index) + local _, e = input:find('\n[ \t]*\r?\n', index) + return (e or #input) + 1 + end))) + +lex:add_rule('blockcode', + token('code', lexer.starts_line(P(' ')^4 + P('\t')) * -P('<') * + lexer.nonnewline^0 * lexer.newline^-1)) +lex:add_style('code', lexer.STYLE_EMBEDDED..',eolfilled') + +lex:add_rule('hr', + token('hr', + lpeg.Cmt(lexer.starts_line(S(' \t')^0 * lpeg.C(S('*-_'))), + function(input, index, c) + local line = input:match('[^\n]*', index) + line = line:gsub('[ \t]', '') + if line:find('[^'..c..']') or #line < 2 then + return nil + end + return (input:find('\n', index) or #input) + 1 + end))) +lex:add_style('hr', 'back:$(color.black),eolfilled') + +lex:add_rule('list', token('list', lexer.starts_line(S(' \t')^0 * (S('*+-') + + R('09')^1 * '.')) * + S(' \t'))) +lex:add_style('list', lexer.STYLE_CONSTANT) + +-- Whitespace. +local ws = token(lexer.WHITESPACE, S(' \t')^1 + S('\v\r\n')^1) +lex:add_rule('whitespace', ws) + +-- Span elements. +lex:add_rule('escape', token(lexer.DEFAULT, P('\\') * 1)) + +lex:add_rule('link_label', + token('link_label', lexer.delimited_range('[]') * ':') * ws * + token('link_url', (lexer.any - lexer.space)^1) * + (ws * token(lexer.STRING, lexer.delimited_range('"', false, true) + + lexer.delimited_range("'", false, true) + + lexer.delimited_range('()')))^-1) +lex:add_style('link_label', lexer.STYLE_LABEL) +lex:add_style('link_url', 'underlined') + +lex:add_rule('link', + token('link', P('!')^-1 * lexer.delimited_range('[]') * + (P('(') * (lexer.any - S(') \t'))^0 * + (S(' \t')^1 * + lexer.delimited_range('"', false, true))^-1 * ')' + + S(' \t')^0 * lexer.delimited_range('[]')) + + P('http://') * (lexer.any - lexer.space)^1)) +lex:add_style('link', 'underlined') + +lex:add_rule('strong', token('strong', P('**') * (lexer.any - '**')^0 * + P('**')^-1 + + P('__') * (lexer.any - '__')^0 * + P('__')^-1)) +lex:add_style('strong', 'bold') +lex:add_rule('em', token('em', lexer.delimited_range('*', true) + + lexer.delimited_range('_', true))) +lex:add_style('em', 'italics') +lex:add_rule('code', token('code', P('``') * (lexer.any - '``')^0 * P('``')^-1 + + lexer.delimited_range('`', true, true))) + +-- Embedded HTML. +local html = lexer.load('html') +local start_rule = lexer.starts_line(S(' \t')^0) * #P('<') * + html:get_rule('element') +local end_rule = token(lexer.DEFAULT, P('\n')) -- TODO: lexer.WHITESPACE errors +lex:embed(html, start_rule, end_rule) + +return lex |