ocaml/man/ocamllex.m

.TH OCAMLLEX 1

.SH NAME
ocamllex \- The Objective Caml lexer generator

.SH SYNOPSIS
.B ocamllex
[
.BI \-o \ output-file
]
[
.B \-ml
]
.I filename.mll

.SH DESCRIPTION

The
.BR ocamllex (1)
command generates Objective Caml lexers from a set of regular
expressions with associated semantic actions, in the style of
.BR lex (1).

Running
.BR ocamllex (1)
on the input file
.IR lexer \&.mll
produces Caml code for a lexical analyzer in file 
.IR lexer \&.ml.

This file defines one lexing function per entry point in the lexer
definition. These functions have the same names as the entry
points. Lexing functions take as argument a lexer buffer, and return
the semantic attribute of the corresponding entry point.

Lexer buffers are an abstract data type implemented in the standard
library module Lexing. The functions Lexing.from_channel,
Lexing.from_string and Lexing.from_function create
lexer buffers that read from an input channel, a character string, or
any reading function, respectively.

When used in conjunction with a parser generated by 
.BR ocamlyacc (1),
the semantic actions compute a value belonging to the type token defined
by the generated parsing module.

.SH OPTIONS

The 
.BR ocamllex (1)
command recognizes the following options:

.TP
.BI \-o \ output-file
Specify the output file name
.IR output-file
instead of the default naming convention.

.TP
.B \-ml
Output code that does not use the Caml built-in automata
interpreter. Instead, the automaton is encoded by Caml functions.
This option is useful for debugging
.BR ocamllex (1),
using it for production lexers is not recommended.

.SH SEE ALSO
.BR ocamlyacc (1).
.br
.I The Objective Caml user's manual,
chapter "Lexer and parser generators".