Lexical analysis is one phase of compilation or interpretation. Given an input sequence of characters they are matched against various patterns (often represented by a RegularExpression) and broken apart into token streams. It is possible that more than one set of characters matches the same token. Each unique set of characters that composes a token is called a lexeme. For example, 1234 may be identified as a number token, but the actual lexeme is the string "1234."

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CategoryCompilers