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compiler-constructionflex-lexer

Very simple query about Flex

I would like to ask you what does this character mean when you are writing a Flex file:

'^'

Solution

  • The ^ symbol is called a caret for future reference. You mean the Fast Lexical Analyzer, right? When you use the caret in patterns, matching, substitutions, etc., it means "the characters EXCEPT..." the ones that follow the caret. It's kind of like a negator, i.e. throwing an exclamation point in front of an equals sign means NOT equals, throwing a caret in front of a pattern means NOT this pattern, or NOT these characters.

    Edit: Here is some decent info you might appreciate.