OCAMLLEX(1)

💖 OCAMLLEX(1) 💖

okay so bestie, welcome to the ocamllex page — it lives in the General Commands Manual and it is literally the OCaml lexer generator. yes, THE one. ✨

🦋 NAME 🦋

ocamllex — the OCaml lexer generator, no cap. 👑

🌸 SYNOPSIS 🌸

ocamllex [ -o output-file ] [ -ml ] filename.mll

✨ DESCRIPTION ✨

so like. the ocamllex(1) command generates OCaml lexers out of a set of regular expressions that have semantic actions attached to them, in the style of lex(1). it's giving classic, it's giving vintage, we love her. 💅

when you run ocamllex(1) on the input file lexer.mll, you get OCaml code for a lexical analyzer in the file lexer.ml. boom. that's the whole glow-up. 🔥

that file defines one lexing function per entry point in the lexer definition, and those functions have the exact same names as the entry points, fr fr. a lexing function takes a lexer buffer as its argument, and it returns the semantic attribute of the corresponding entry point. that's it, that's the job. 🫶

lexer buffers are an abstract data type implemented in the standard library module Lexing. and 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. three lil besties, three lil sources of input. 🌈

and when you use this in conjunction with a parser generated by ocamlyacc(1), the semantic actions compute a value belonging to the type token defined by the generated parsing module. iconic collaboration honestly. 🎀

💅 OPTIONS 💅

the ocamllex(1) command recognizes the following options, bestie, and we are going through every single one:

• -ml — outputs code that does not use OCaml's built-in automata interpreter. instead, the automaton gets encoded by OCaml functions. this one is mainly useful for debugging ocamllex(1) — and using it for production lexers is not recommended. so like, cute for snooping, not for shipping. 🙈
• -o output-file — specify the name of the output file that ocamllex(1) produces. the default is the input file name, with its extension replaced by .ml. so you get a say in where it goes 💖
• -q — quiet mode. ocamllex(1) normally outputs informational messages to standard output, and they get suppressed if you use option -q. shy girl era. 🤫
• -v or -version — print version string and exit. 🦋
• -vnum — print short version number and exit. short and sweet. ⭐
• -help or --help — display a short usage summary and exit. the tutorial, but tiny. 🌸

👑 SEE ALSO 👑

• ocamlyacc(1).
• The OCaml user's manual, chapter "Lexer and parser generators".

ok that's the whole page, you ate it up, go generate some lexers 💖

and that's a wrap, bestie — this was OCAMLLEX(1) from the General Commands Manual, and we are obsessed. mwah, bye 🎀💜