1 files changed, 54 insertions, 0 deletions
diff --git a/lexlua/dot.lua b/lexlua/dot.lua
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index 000000000..54d55a458
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+++ b/lexlua/dot.lua
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+-- Copyright 2006-2018 Brian "Sir Alaran" Schott. See License.txt.
+-- Dot LPeg lexer.
+-- Based off of lexer code by Mitchell.
+
+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('dot')
+
+-- Whitespace.
+lex:add_rule('whitespace', token(lexer.WHITESPACE, lexer.space^1))
+
+-- Keywords.
+lex:add_rule('keyword', token(lexer.KEYWORD, word_match[[
+  graph node edge digraph fontsize rankdir fontname shape label arrowhead
+  arrowtail arrowsize color comment constraint decorate dir headlabel headport
+  headURL labelangle labeldistance labelfloat labelfontcolor labelfontname
+  labelfontsize layer lhead ltail minlen samehead sametail style taillabel
+  tailport tailURL weight subgraph
+]]))
+
+-- Types.
+lex:add_rule('type', token(lexer.TYPE, word_match[[
+	box polygon ellipse circle point egg triangle plaintext diamond trapezium
+  parallelogram house pentagon hexagon septagon octagon doublecircle
+  doubleoctagon tripleoctagon invtriangle invtrapezium invhouse Mdiamond Msquare
+  Mcircle rect rectangle none note tab folder box3d record
+]]))
+
+-- Identifiers.
+lex:add_rule('identifier', token(lexer.IDENTIFIER, lexer.word))
+
+-- Strings.
+lex:add_rule('string', token(lexer.STRING, lexer.delimited_range("'") +
+                                           lexer.delimited_range('"')))
+
+-- Comments.
+local line_comment = '//' * lexer.nonnewline_esc^0
+local block_comment = '/*' * (lexer.any - '*/')^0 * P('*/')^-1
+lex:add_rule('comment', token(lexer.COMMENT, line_comment + block_comment))
+
+-- Numbers.
+lex:add_rule('number', token(lexer.NUMBER, lexer.digit^1 + lexer.float))
+
+-- Operators.
+lex:add_rule('operator', token(lexer.OPERATOR, S('->()[]{};')))
+
+-- Fold points.
+lex:add_fold_point(lexer.OPERATOR, '{', '}')
+lex:add_fold_point(lexer.COMMENT, '/*', '*/')
+lex:add_fold_point(lexer.COMMENT, '//', lexer.fold_line_comments('//'))
+
+return lex