6 Mar 2000 00:32:26 -0500

Related articles |
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Computing FIRST(X) for a left recursive grammar muzzetta@videobank.it (2000-03-06) |

Re: Computing FIRST(X) for a left recursive grammar vugluskr@unicorn.math.spbu.ru (2000-03-06) |

Re: Computing FIRST(X) for a left recursive grammar torbenm@diku.dk (2000-03-06) |

Re: Computing FIRST(X) for a left recursive grammar joachim.durchholz@halstenbach.com.or.de (Joachim Durchholz) (2000-03-06) |

Re: Computing FIRST(X) for a left recursive grammar rsherry@home.com (Robert Sherry) (2000-03-07) |

Re: Computing FIRST(X) for a left recursive grammar johnmce@texas.net (2000-03-07) |

From: | muzzetta@videobank.it (Alessandro Muzzetta) |

Newsgroups: | comp.compilers |

Date: | 6 Mar 2000 00:32:26 -0500 |

Organization: | Compilers Central |

Keywords: | LALR |

Hello,

can some kind soul please answer this silly question of mine...

Assuming you have the following yacc rules

list: /* empty */

| list NEWLINE

| list expr NEWLINE

;

expr: ...

;

How do I calculate FIRST(list) for this left recursive grammar? I'm

working on an SLR parser generator, and I don't know how to handle

this case. What should FIRST(list) contain besides the empty string?

FIRST(NEWLINE) and FIRST(expr)??? Wouldn't that be the follow set of

list?

Another question: what are suitable data structures for representing

sets of arbitrary strings denoting the first/follow set of a symbol?

Fast insertions are necessary.

Thanks

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