php-regex / regex-language-server

2.x-dev 2026-10-05 22:20 UTC

Requires

• php: >=8.2
• php-regex/regex-explain: ^2.0
• php-regex/regex-linter: ^2.0
• php-regex/regex-parser: ^2.0
• php-regex/regex-toolkit: ^2.0

MIT

• Younes ENNAJI

• editor
• regex
• PCRE
• LSP
• language-server

Published on Packagist.org on 2026-10-05 22:21 UTC

README

PHPRegex Language Server

A language server for the regex patterns of PHP files: diagnostics, hovers, completions and code actions in any LSP editor.

The server reads PHP source over stdio, finds the regex literals in it — the patterns of preg_* calls and of wrapper calls such as Preg::match() — and answers in JSON-RPC, so every LSP editor can check patterns while you type.

Features

• Diagnostics on open and on change: every pattern of the file is parsed and linted, and the findings are published to the editor.
• Hovers in plain English: hold the pointer on a pattern to read what it matches, token by token.
• Completions inside patterns: shorthands after a backslash, Unicode properties after \p{, POSIX classes after [:, groups after (?, flags after the closing delimiter.
• Code actions: one action adds the u flag a Unicode pattern lacks, one applies the optimizer's rewrite — /[0-9]{1,}/ becomes /\d+/.
• One target per workspace: patterns are judged for one PHP and PCRE2 pair, resolved from the editor settings, regex.json, composer.json or the running PHP.

Installation

composer require --dev php-regex/regex-language-server

Requires PHP 8.2+. The binary is installed as vendor/bin/regex-lsp; --help prints its options, --version the release it was built from.

Configuration

Every pattern of the workspace is judged for one target, a PHP and PCRE2 pair, resolved once at initialize and logged where the editor shows the server output (Target: PHP 8.4, PCRE2 10.49 (running PHP)).

Option	Accepts	When absent
initializationOptions.phpVersion	"8.2", "8.2.4" or 80200	phpVersion in regex.json, then composer.json, then the running PHP
initializationOptions.pcreVersion	a PCRE2 release, "10.42" for instance	pcreVersion in regex.json, then the release the target PHP bundles

regex.json (and regex.dist.json) sits at the root of the first workspace folder. A value the server cannot read is logged as a warning and the next source is used. Changing the target takes a server restart.

Usage

A file opens, and a broken pattern is reported where it sits. This notification was captured from a live session:

{"jsonrpc":"2.0","method":"textDocument/publishDiagnostics","params":{"uri":"file:///demo/Mailer.php","diagnostics":[
  {"range":{"start":{"line":2,"character":13},"end":{"line":2,"character":16}},"severity":1,"code":"regex.delimiter.unclosed",
   "source":"php-regex","message":"No closing delimiter \"/\" found. You opened with \"/\"; expected closing \"/\". Tip: escape \"/\" inside the pattern (\\/) or use a different delimiter, e.g. #[a-#."}]}}

Hovering the pattern /^\w+@\w+\.\w+$/ returns this markdown (abridged):

**Regex Pattern**

```
/^\w+@\w+\.\w+$/
```

**Explanation**

Regex matches
  Anchor: the beginning of a line
    Character Type: A word character: [a-zA-Z_0-9] (one or more times)
  …
  Anchor: the end of a line

Code actions are offered on the pattern they fix:

• /\p{L}+/ without the u flag gets "Add /u flag for Unicode support", rewriting the literal to '/\p{L}+/u'.
• /[0-9]{1,}/ gets "Apply regex optimization", rewriting the literal to '/\d+/'.

Integration

VS Code

Any LSP client extension; .vscode/settings.json:

{
  "lsp.servers": {
    "php-regex": {
      "command": ["vendor/bin/regex-lsp"],
      "filetypes": ["php"]
    }
  }
}

PhpStorm

Install LSP4IJ from the JetBrains Marketplace, then Settings → Languages & Frameworks → Language Servers: a server definition named PHPRegex, command vendor/bin/regex-lsp, file mappings *.php.

Neovim

init.lua with nvim-lspconfig:

local lspconfig = require('lspconfig')
local configs = require('lspconfig.configs')
if not configs.php_regex then
  configs.php_regex = {
    default_config = {
      cmd = { 'vendor/bin/regex-lsp' },
      filetypes = { 'php' },
      root_dir = lspconfig.util.root_pattern('composer.json', '.git'),
    },
  }
end
lspconfig.php_regex.setup({})

Vim, Emacs, Sublime Text, Helix and Zed are wired the same way; the LSP guide holds each snippet.

Documentation

• LSP guide — editor configurations, supported methods, troubleshooting.
• Diagnostics reference — the codes the server publishes and how to read them.
• Backward compatibility promise — what stays stable across releases.

Resources

• Documentation
• Report issues and send pull requests in the main PHPRegex repository
• Changelog

Sponsors

If PHPRegex saves you time, consider sponsoring its maintenance.

License

MIT. See LICENSE.