Allocators

What you'll learn

• Why only Parser.init takes an allocator and how every other object inherits it.

The one-allocator rule

var parser = treesitter.Parser.init(allocator); // ← the single handoff
defer parser.deinit();

var tree = try parser.parseString(src); // inherits parser allocator
var cursor = tree.cursor(); // inherits tree allocator
var query = try parser.compileQuery("(identifier) @id"); // inherits parser allocator
var qcursor = parser.queryCursor(); // inherits parser allocator

Standalone constructors (TreeCursor.init(gpa, node), Query.compile(gpa, lang, src), QueryCursor.init(gpa), getChangedRanges(gpa, a, b)) still exist for code that builds those objects without a parser or tree. Prefer the inheriting forms in application code.

Choosing an allocator

Allocator	Use for
std.heap.DebugAllocator	Development, tests, leak detection (what the test suite uses)
std.heap.ArenaAllocator	Batch jobs: parse thousands of files, then free once
std.heap.FixedBufferAllocator	Embedded budgets and allocation-failure testing
std.heap.SmpAllocator / page allocator	Long-lived editor-grade processes

The test suite exercises std.testing.failing_allocator to prove OutOfMemory propagates without leaks or corruption.

API used

• Allocator, Parser.

Related guides

• Memory Management, Testing