LALR parser generator: Difference between revisions

Revision as of 09:32, 15 July 2021

Revision as of 01:55, 30 March 2022

Line 1:

{{Refimprove|date=August 2011}}

A '''lookahead left-to-rightLR parser (LALR) parser generator''' is a software tool that reads a [[BNF grammar]] and creates an [[LALR parser]] which is capable of parsing files written in the [[computer language]] defined by the BNF grammar. [[LALR parser]]s are desirable because they are very fast and small in comparison to other types of parsers.

There are other types of [[parser generator]]s, such as [[Simple LR parser]], [[LR parser]], [[GLR parser]], [[LL parser]] and [[GLL parser]] generators. What differentiates one from another is the type of BNF grammar which they are capable of accepting and the type of parsing algorithm which is used in the generated parser. An LALR parser generator accepts an LALR grammar as input and generates a parser that uses an LALR parsing algorithm (which is driven by LALR parser tables).