Wed, 09 Sep 2009 18:40:55 +0200

Related articles |
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[2 earlier articles] |

Re: parser generator terminology DrDiettrich1@aol.com (Hans-Peter Diettrich) (2009-09-06) |

Re: parser generator terminology cfc@shell01.TheWorld.com (Chris F Clark) (2009-09-06) |

Re: parser generator terminology cfc@shell01.TheWorld.com (Chris F Clark) (2009-09-07) |

Re: parser generator terminology haberg_20080406@math.su.se (Hans Aberg) (2009-09-07) |

Re: parser generator terminology mhelvens@gmail.com (Michiel) (2009-09-07) |

Re: parser generator terminology cfc@shell01.TheWorld.com (Chris F Clark) (2009-09-07) |

Re: parser generator terminology haberg_20080406@math.su.se (Hans Aberg) (2009-09-09) |

Re: parser generator terminology cfc@shell01.TheWorld.com (Chris F Clark) (2009-09-13) |

Re: parser generator terminology haberg_20080406@math.su.se (Hans Aberg) (2009-09-14) |

Re: parser generator terminology gneuner2@comcast.net (George Neuner) (2009-09-14) |

From: | Hans Aberg <haberg_20080406@math.su.se> |

Newsgroups: | comp.compilers |

Date: | Wed, 09 Sep 2009 18:40:55 +0200 |

Organization: | A noiseless patient Spider |

References: | 09-09-038 09-09-039 09-09-045 09-09-048 |

Keywords: | parse, theory |

Posted-Date: | 10 Sep 2009 04:07:55 EDT |

Chris F Clark wrote:

*>> In Waite & Goos, the vocabulary V is the (disjoint) union of the sets of*

*>> non-terminals and terminals. They first defines a general rewriting*

*>> system, with sentences members of V*, the set of finite strings (the*

*>> free monoid) of V.*

...

*> While I'm not so foolish as to argue with Waite, Goos, or the Bison*

*> maintainers, epseically when I've Seen V, VT, and VN used rather*

*> universally as the 3 sets of all symbols, terminals, and*

*> non-terminals, there is precedence for vocbulary as VT, given that*

*> Terence Parr uses it in ANTLR if I recall correctly.*

This is not formally wrong: V can be any finite set of symbols. A

language is then a subset of V*. So it is OK to define a language L as a

subset of T*, in which case the set of terminals T is the vocabulary.

The set of non-terminals N is only needed when one wants to define a

general rewriting system from a grammar to define the language L.

Different grammar specs of L may lead to different N.

Hans

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