alto/language

Alto PHP library for programming language identification: extensions, aliases, markers, indentations

v1.0.0 2026-02-22 05:30 UTC

Requires

• php: >=8.4

Requires (Dev)

• friendsofphp/php-cs-fixer: ^3.0
• phpstan/phpstan: ^2.0
• phpunit/phpunit: ^12.0

MIT

• code
• extensions
• language
• programming
• identification
• linguist
• code-markers
• linguee

README

A lightweight PHP library providing structured metadata for 62 programming languages — extensions, aliases, filenames, syntax markers, and more.

Zero dependencies. 100% test coverage. PHP 8.4+.

Installation

composer require alto/language

Quick Start

use Alto\Language\Languages;

// Lookup by slug
$php = Languages::get('php');
$php->name;       // "PHP"
$php->extensions; // [".php", ".phtml", ".php3", …]
$php->type;       // LanguageType::Programming

// Lookup by file extension
Languages::fromExtension('.ts');       // → typescript
Languages::fromExtension('rs');        // → rust (dot is optional)

// Lookup by alias
Languages::fromAlias('py');            // → python
Languages::fromAlias('jsx');           // → javascript

// Lookup by filename
Languages::fromFilename('Dockerfile'); // → dockerfile
Languages::fromFilename('Makefile');   // → makefile
Languages::fromFilename('.gitignore'); // → ignore

// Compound extension fallback
Languages::fromFilename('phpunit.xml.dist'); // → xml

// Resolve from any identifier (slug → alias → extension → filename)
Languages::resolve('typescript');      // by slug
Languages::resolve('ts');             // by alias
Languages::resolve('.tsx');           // by extension
Languages::resolve('Makefile');       // by filename

API

Static Facade (Languages)

Method	Returns	Description
Languages::get($slug)	?Language	Lookup by slug
Languages::fromExtension($ext)	?Language	Lookup by file extension
Languages::fromAlias($alias)	?Language	Lookup by alias
Languages::fromFilename($name)	?Language	Lookup by exact filename or extension
Languages::resolve($identifier)	?Language	Try all lookup methods in order
Languages::all()	Language[]	All registered languages
Languages::ofType($type)	Language[]	Filter by LanguageType
Languages::children($slug)	Language[]	Languages whose parent is the given slug
Languages::conflicts()	array	Extension/alias/filename collisions

Injectable Registry (LanguageRegistry)

All facade methods delegate to LanguageRegistry, which can be injected directly:

use Alto\Language\LanguageRegistry;

$registry = new LanguageRegistry();
$python = $registry->get('python');

Language Object

Each Language is an immutable value object:

$lang = Languages::get('typescript');

$lang->name;       // "TypeScript"
$lang->slug;       // "typescript"
$lang->type;       // LanguageType::Programming
$lang->extensions; // [".ts", ".tsx", ".mts", ".cts"]
$lang->aliases;    // ["ts"]
$lang->filenames;  // []
$lang->year;       // 2012
$lang->parent;     // "javascript"
$lang->markers;    // CodeMarkers instance

Languages are JSON-serializable:

json_encode(Languages::get('go'));

Code Markers

Syntax fingerprints attached to each language:

$markers = Languages::get('php')->markers;

$markers->lineComments;     // ["//", "#"]
$markers->blockComments;    // [["/*", "*/"]]
$markers->docComment;       // ["/**", "*/"]
$markers->stringDelimiters; // ["\"", "'"]
$markers->heredoc;          // true
$markers->shebang;          // "#!/usr/bin/env php"
$markers->openingTag;       // "<?php"
$markers->typicalHeaders;   // ["<?php", "<?="]
$markers->blockStyle;       // BlockStyle::Braces
$markers->defaultIndentation; // 4
$markers->indentStyle;      // IndentStyle::Spaces

Enums

LanguageType — categorizes languages by purpose:

Programming, Markup, Data, Prose, Query, Stylesheet, Template, Config, Other

BlockStyle — code block delimiters:

Braces, Indentation, BeginEnd, Tags, None

IndentStyle — default indentation:

Spaces, Tabs

Languages

62 languages included:

Language	Extensions	Type
Bash	.sh, .bash	Programming
C	.c, .h	Programming
C#	.cs	Programming
C++	.cpp, .cc, .cxx, .hpp	Programming
Clojure	.clj, .cljs, .cljc	Programming
CMake	.cmake	Programming
CoffeeScript	.coffee	Programming
CSS	.css	Stylesheet
Dart	.dart	Programming
Diff	.diff, .patch	Data
Dockerfile	—	Config
Dotenv	—	Config
Elixir	.ex, .exs	Programming
Erlang	.erl, .hrl	Programming
F#	.fs, .fsi, .fsx	Programming
Git Attributes	—	Config
Git Config	—	Config
Go	.go	Programming
GraphQL	.graphql, .gql	Query
Groovy	.groovy, .gvy	Programming
Haskell	.hs, .lhs	Programming
HCL	.hcl, .tf	Programming
htaccess	—	Config
HTML	.html, .htm	Markup
HTTP	.http, .rest	Data
Ignore	—	Config
INI	.ini, .cfg	Config
Java	.java	Programming
JavaScript	.js, .mjs, .cjs, .jsx	Programming
JSON	.json	Data
Julia	.jl	Programming
Just	—	Config
Kotlin	.kt, .kts	Programming
Less	.less	Stylesheet
Lua	.lua	Programming
Makefile	—	Programming
Markdown	.md, .markdown	Prose
NEON	.neon	Config
Nix	.nix	Programming
Objective-C	.m, .mm	Programming
OCaml	.ml, .mli	Programming
Perl	.pl, .pm	Programming
PHP	.php, .phtml	Programming
PowerShell	.ps1, .psm1	Programming
Procfile	—	Config
Protocol Buffers	.proto	Data
Python	.py, .pyw	Programming
R	.r, .R	Programming
Ruby	.rb	Programming
Rust	.rs	Programming
Sass	.sass	Stylesheet
Scala	.scala, .sc	Programming
SCSS	.scss	Stylesheet
SQL	.sql	Query
SVG	.svg	Markup
Swift	.swift	Programming
TOML	.toml	Config
Twig	.twig	Template
TypeScript	.ts, .tsx, .mts, .cts	Programming
XML	.xml, .xsl, .xsd	Markup
YAML	.yml, .yaml	Data
Zig	.zig	Programming

Languages with filename-based matching (no extension): Dockerfile, Makefile, .gitignore, .env, Procfile, Justfile, .htaccess, and more.

Contributing

Contributions are welcome! Please feel free to submit issues or pull requests.

Adding a Language

Create a new file in data/languages/:

<?php
// data/languages/mylang.php

use Alto\Language\CodeMarkers;
use Alto\Language\Language;
use Alto\Language\LanguageType;

return new Language(
    name: 'MyLang',
    slug: 'mylang',
    type: LanguageType::Programming,
    extensions: ['.ml'],
    aliases: ['my'],
    markers: new CodeMarkers(
        lineComments: ['//'],
        blockComments: [['/*', '*/']],
    ),
);

License

Released by the Alto project under the MIT License. See the LICENSE file for details.