Parser Types

Galore supports three types of bottom-up parsers. Each has different trade-offs between power and complexity.

SLR (Simple LR)

The simplest LR parser. Uses FOLLOW sets to resolve conflicts.

• Smallest parse tables
• Fastest to construct
• Can handle fewer grammars than LALR or LR(1)

const parser = G.newParser(grammar, { type: "slr" });

LALR (Look-Ahead LR)

The most commonly used parser type. Balances power and efficiency.

• Same table size as SLR
• More powerful than SLR
• Used by tools like Yacc and Bison

const parser = G.newParser(grammar, { type: "lalr" });

LR(1) (Canonical LR)

The most powerful LR parser. Uses full lookahead information.

• Largest parse tables
• Can handle all deterministic context-free grammars
• More memory intensive

const parser = G.newParser(grammar, { type: "lr1" });

Comparison

Parser Type	Table Size	Power	Use Case
SLR	Small	Limited	Simple grammars
LALR	Small	Good	Most programming languages
LR(1)	Large	Full	Complex grammars