ocamlyacc - The OCaml parser generator
ocamlyacc [ -bprefix ] [ -q ] [ -v ] [
-version ] [ -vnum ] filename.mly
The ocamlyacc(1) command produces a parser from a LALR(1) context-free
grammar specification with attached semantic actions, in the style of
yacc(1). Assuming the input file is grammar.mly, running
ocamlyacc produces OCaml code for a parser in the file
grammar.ml, and its interface in file grammar.mli.
The generated module defines one parsing function per entry point
in the grammar. These functions have the same names as the entry points.
Parsing functions take as arguments a lexical analyzer (a function from
lexer buffers to tokens) and a lexer buffer, and return the semantic
attribute of the corresponding entry point. Lexical analyzer functions are
usually generated from a lexer specification by the ocamllex(1)
program. Lexer buffers are an abstract data type implemented in the standard
library module Lexing. Tokens are values from the concrete type token,
defined in the interface file grammar.mli produced by
The ocamlyacc(1) command recognizes the following options:
- Name the output files prefix.ml, prefix.mli,
prefix.output, instead of the default naming convention.
- This option has no effect.
- Reject grammars with conflicts.
- Generate a description of the parsing tables and a report on conflicts
resulting from ambiguities in the grammar. The description is put in file
- Print version string and exit.
- Print short version number and exit.
- Read the grammar specification from standard input. The default output
file names are stdin.ml and stdin.mli.
- -- file
- Process file as the grammar specification, even if its name starts
with a dash (-) character. This option must be the last on the command
The OCaml user's manual, chapter "Lexer and parser generators".