Crate php_rs_parser 

Fast, fault-tolerant PHP parser that produces a fully typed AST.

This crate parses PHP source code (PHP 7.4–8.5) into a php_ast::Program tree, recovering from syntax errors so that downstream tools always receive a complete AST.

Semantic-rejection responsibility

The parser is fault-tolerant: it always produces an AST and reports every error it can identify before recovering. Its semantic-rejection responsibility is defined externally:

For any input, the parser emits at least one diagnostic iff php -l would reject that input at the configured target PHP version.

Flow-sensitive checks — cross-file resolution, unused variables, dead code, type-mismatched returns — are out of scope and belong in a later semantic layer. Checks decidable from one declaration, one parameter list, one modifier set, or one declaration loop are in scope and use diagnostics::ParseError::Forbidden.

The ===php_error=== section in tests/fixtures/**/*.phpt records php -l output; the fixture runner enforces the rule above by failing CI when PHP rejects an input that the parser silently accepts.

Quick start

let arena = bumpalo::Bump::new();
let result = php_rs_parser::parse(&arena, "<?php echo 'hello';");
assert!(result.errors.is_empty());

Version-aware parsing

Use parse_versioned to target a specific PHP version. Syntax that requires a higher version is still parsed into the AST, but a diagnostics::ParseError::VersionTooLow diagnostic is emitted.

let arena = bumpalo::Bump::new();
let result = php_rs_parser::parse_versioned(
    &arena,
    "<?php enum Status { case Active; }",
    php_rs_parser::PhpVersion::Php80,
);
assert!(!result.errors.is_empty()); // enums require PHP 8.1

Reusing arenas across re-parses (LSP usage)

Use ParserContext to avoid allocator churn when the same document is re-parsed on every edit. The context owns a bumpalo::Bump arena and resets it in O(1) before each parse, reusing the backing memory once it has grown to a stable size.

let mut ctx = php_rs_parser::ParserContext::new();

let result = ctx.reparse("<?php echo 1;");
assert!(result.errors.is_empty());
drop(result); // must be dropped before the next reparse

let result = ctx.reparse("<?php echo 2;");
assert!(result.errors.is_empty());

Re-exports

pub use version::PhpVersion;

pub use phpdoc_parser as phpdoc;

Modules

diagnostics

instrument

Lightweight instrumentation for profiling array parsing, expression parsing, and statement parsing.

source_map

version

Structs

ParseResult

The result of parsing a PHP source string.

ParserContext

A reusable parse context that keeps a bumpalo::Bump arena alive between re-parses, resetting it (O(1)) instead of dropping and reallocating.

Functions

parse

Parse PHP source using the latest supported PHP version (currently 8.5).

parse_versioned

Parse source targeting the given PHP version.