Canonical LR parser

In computer science, a canonical LR parser or LR(1) parser is an LR(k) parser for k=1, i.e. with a single lookahead terminal. The special attribute of this parser is that all LR(k) parsers with k>1 can be transformed into a LR(1) parser. It can handle all deterministic context-free languages. In the past this LR(k) parser has been avoided because of its huge memory requirements in favor of less powerful alternatives such as the LALR and the LL(1) parser. Recently, however, a "minimal LR(1) parser" whose space requirements are close to LALR parsers, is being offered by several parser generators.