Friday, April 27, 2012


  • The Context Free Grammar is an Essential Concept for the implementation of compiler and other programming Language Processor.
  • Tools such as YACC take a CFG as input and produce a Parser, the component of a compiler that deduce the structure of the program being compiled.
  • Suppose that G  is a Context Free Grammar over an Alphabet Σ. To Parse a string  x є Σ* is often useful.
  • Parsing a statement in a programming Language, for example, is necessary in order to classify it according to syntax.
  • Parsing an algebraic expression is essentially what allows us to evaluate the expression.
  • There are main two different way of parsing.
        (1) Top Down Parsing
        (2) Bottom Up Parsing