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Diffstat (limited to 'lexlua/crystal.lua')
| -rw-r--r-- | lexlua/crystal.lua | 122 |
1 files changed, 122 insertions, 0 deletions
diff --git a/lexlua/crystal.lua b/lexlua/crystal.lua new file mode 100644 index 000000000..75f9437a6 --- /dev/null +++ b/lexlua/crystal.lua @@ -0,0 +1,122 @@ +-- Copyright 2006-2018 Mitchell mitchell.att.foicica.com. See License.txt. +-- Copyright 2017 Michel Martens. +-- Crystal LPeg lexer (based on Ruby). + +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('crystal') + +-- Whitespace. +lex:add_rule('whitespace', token(lexer.WHITESPACE, lexer.space^1)) + +-- Keywords. +lex:add_rule('keyword', token(lexer.KEYWORD, word_match[[ + alias begin break case class def defined? do else elsif end ensure false for + if in module next nil not redo rescue retry return self super then true undef + unless until when while yield __FILE__ __LINE__ +]])) + +-- Functions. +lex:add_rule('function', token(lexer.FUNCTION, word_match[[ + abort at_exit caller delay exit fork future get_stack_top gets lazy loop main + p print printf puts raise rand read_line require sleep spawn sprintf system + with_color + -- Macros. + assert_responds_to debugger parallel pp record redefine_main +]]) * -S('.:|')) + +-- Identifiers. +local word_char = lexer.alnum + S('_!?') +local word = (lexer.alpha + '_') * word_char^0 +local identifier = token(lexer.IDENTIFIER, word) + +local delimiter_matches = {['('] = ')', ['['] = ']', ['{'] = '}'} +local literal_delimitted = P(function(input, index) + local delimiter = input:sub(index, index) + if not delimiter:find('[%w\r\n\f\t ]') then -- only non alpha-numerics + local match_pos, patt + if delimiter_matches[delimiter] then + -- Handle nested delimiter/matches in strings. + local s, e = delimiter, delimiter_matches[delimiter] + patt = lexer.delimited_range(s..e, false, false, true) + else + patt = lexer.delimited_range(delimiter) + end + match_pos = lpeg.match(patt, input, index) + return match_pos or #input + 1 + end +end) + +-- Comments. +lex:add_rule('comment', token(lexer.COMMENT, '#' * lexer.nonnewline_esc^0)) + +-- Strings. +local cmd_str = lexer.delimited_range('`') +local sq_str = lexer.delimited_range("'") +local dq_str = lexer.delimited_range('"') +local heredoc = '<<' * P(function(input, index) + local s, e, indented, _, delimiter = + input:find('(%-?)(["`]?)([%a_][%w_]*)%2[\n\r\f;]+', index) + if s == index and delimiter then + local end_heredoc = (#indented > 0 and '[\n\r\f]+ *' or '[\n\r\f]+') + local _, e = input:find(end_heredoc..delimiter, e) + return e and e + 1 or #input + 1 + end +end) +-- TODO: regex_str fails with `obj.method /patt/` syntax. +local regex_str = #P('/') * lexer.last_char_includes('!%^&*([{-=+|:;,?<>~') * + lexer.delimited_range('/', true, false) * S('iomx')^0 +lex:add_rule('string', token(lexer.STRING, (sq_str + dq_str + heredoc + + cmd_str) * S('f')^-1) + + token(lexer.REGEX, regex_str)) + +-- Numbers. +local dec = lexer.digit^1 * ('_' * lexer.digit^1)^0 * S('ri')^-1 +local bin = '0b' * S('01')^1 * ('_' * S('01')^1)^0 +local integer = S('+-')^-1 * (bin + lexer.hex_num + lexer.oct_num + dec) +-- TODO: meta, control, etc. for numeric_literal. +local numeric_literal = '?' * (lexer.any - lexer.space) * -word_char +lex:add_rule('number', token(lexer.NUMBER, lexer.float * S('ri')^-1 + integer + + numeric_literal)) + +-- Variables. +local global_var = '$' * (word + S('!@L+`\'=~/\\,.;<>_*"$?:') + lexer.digit + + '-' * S('0FadiIKlpvw')) +local class_var = '@@' * word +local inst_var = '@' * word +lex:add_rule('variable', token(lexer.VARIABLE, global_var + class_var + + inst_var)) + +-- Symbols. +lex:add_rule('symbol', token('symbol', ':' * P(function(input, index) + if input:sub(index - 2, index - 2) ~= ':' then return index end +end) * (word_char^1 + sq_str + dq_str))) +lex:add_style('symbol', lexer.STYLE_CONSTANT) + +-- Operators. +lex:add_rule('operator', token(lexer.OPERATOR, S('!%^&*()[]{}-=+/|:;.,?<>~'))) + +-- Fold points. +local function disambiguate(text, pos, line, s) + return line:sub(1, s - 1):match('^%s*$') and + not text:sub(1, pos - 1):match('\\[ \t]*\r?\n$') and 1 or 0 +end +lex:add_fold_point(lexer.KEYWORD, 'begin', 'end') +lex:add_fold_point(lexer.KEYWORD, 'case', 'end') +lex:add_fold_point(lexer.KEYWORD, 'class', 'end') +lex:add_fold_point(lexer.KEYWORD, 'def', 'end') +lex:add_fold_point(lexer.KEYWORD, 'do', 'end') +lex:add_fold_point(lexer.KEYWORD, 'for', 'end') +lex:add_fold_point(lexer.KEYWORD, 'module', 'end') +lex:add_fold_point(lexer.KEYWORD, 'if', disambiguate) +lex:add_fold_point(lexer.KEYWORD, 'while', disambiguate) +lex:add_fold_point(lexer.KEYWORD, 'unless', disambiguate) +lex:add_fold_point(lexer.KEYWORD, 'until', disambiguate) +lex:add_fold_point(lexer.OPERATOR, '(', ')') +lex:add_fold_point(lexer.OPERATOR, '[', ']') +lex:add_fold_point(lexer.OPERATOR, '{', '}') +lex:add_fold_point(lexer.OPERATOR, '#', lexer.fold_line_comments('#')) + +return lex |