Lab for Automated Reasoning and Analysis LARA

Lecturecise 02: Formal Languages and Lexical Analysis

Slides: pptx, pdf

Terminology: lexical analyzer = lexer = scanner

Key insights:

  • lexical analyzer maps a stream of characters into a stream of tokens
    • while doing that, it typically needs only finite memory
  • we can specify tokens for a lexical analyzers using regular expressions
  • it is not difficult to construct a lexical analyzer manually – we give an example
  • in such case, we often use the first character to decide on token class; there is a notion first(L) = { a | aw in L }

Hand-Written Scanner for While Language

References

Background on regular languages and automata

 
cc12/lecturecise_02.txt · Last modified: 2012/09/24 14:13 by vkuncak
 
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