Also found in: Encyclopedia.
LALRLook Ahead Left to Right
Copyright 1988-2018, All rights reserved.
References in periodicals archive ?
A few modifications and additions are necessary to make them useful for applications: SLR and LALR parsing, attribute evaluation, and an error recovery mechanism.
Fortunately, most realistic formal languages are already amenable to treatment by SLR or LALR parsers which introduce lookahead into essentially LR(0) parsers.
G Size (G) Mossin LR 7PS-LR SLR [G.sub.1] 24 1608 652 1236 491 [G.sub.2] 48 3751 2070 2999 1197 [G.sub.3] 123 6181 5870 7294 2700 The LALR method uses a more precise method of computing the lookahead, but also works by decorating an LR(0) parser [DeRemer 1969].
Unfortunately, all efficient methods of computing LALR lookahead sets require access to the entire LR(0) automaton in advance [DeRemer and Pennello 1982; Park et al.
To demonstrate the feasibility of effective error recovery in our approach, we have implemented two realistic algorithms: the grammar-assisted method of Yacc [Johnson 1975] based on error productions and the fully automatic technique of Rohrich [1980] as implemented in the Lalr parser generator [Grosch 1990].