| 1: | <?php declare(strict_types = 1); |
| 2: | |
| 3: | namespace PHPStan\Type; |
| 4: | |
| 5: | use PHPStan\Turbo\ShadowedByTurboExtension; |
| 6: | use function spl_object_id; |
| 7: | |
| 8: | #[ShadowedByTurboExtension(implementation: __DIR__ . '/../../turbo-ext/src/TypeTraverser.cpp')] |
| 9: | final class TypeTraverser |
| 10: | { |
| 11: | |
| 12: | /** @var callable(Type $type, callable(Type): Type $traverse): Type */ |
| 13: | private $cb; |
| 14: | |
| 15: | /** |
| 16: | * Results of mapMemoized() keyed by spl_object_id() of the mapped type, |
| 17: | * null in map(). The mapped type is kept alive next to its result so that |
| 18: | * its id cannot be reused by another object during the traversal. |
| 19: | * |
| 20: | * @var array<int, array{Type, Type}>|null |
| 21: | */ |
| 22: | private ?array $memo = null; |
| 23: | |
| 24: | /** |
| 25: | * Map a Type recursively |
| 26: | * |
| 27: | * For every Type instance, the callback can return a new Type, and/or |
| 28: | * decide to traverse inner types or to ignore them. |
| 29: | * |
| 30: | * The following example converts constant strings to objects, while |
| 31: | * preserving unions and intersections: |
| 32: | * |
| 33: | * ```php |
| 34: | * TypeTraverser::map($type, function (Type $type, callable $traverse): Type { |
| 35: | * if ($type instanceof UnionType || $type instanceof IntersectionType) { |
| 36: | * // Traverse inner types |
| 37: | * return $traverse($type); |
| 38: | * } |
| 39: | * if ($type instanceof ConstantStringType) { |
| 40: | * // Replaces the current type, and don't traverse |
| 41: | * return new ObjectType($type->getValue()); |
| 42: | * } |
| 43: | * // Replaces the current type, and don't traverse |
| 44: | * return new MixedType(); |
| 45: | * }); |
| 46: | * ``` |
| 47: | * |
| 48: | * @api |
| 49: | * @param TypeTraverserCallable|callable(Type $type, callable(Type): Type $traverse): Type $cb |
| 50: | */ |
| 51: | public static function map(Type $type, TypeTraverserCallable|callable $cb): Type |
| 52: | { |
| 53: | $self = new self($cb); |
| 54: | |
| 55: | return $self->mapInternal($type); |
| 56: | } |
| 57: | |
| 58: | /** |
| 59: | * Like map(), but the callback is called only once for each Type instance: |
| 60: | * a Type instance occurring repeatedly in the traversed type (e.g. a type |
| 61: | * alias used in many offsets of an array shape) is replaced with the result |
| 62: | * of its first occurrence, without traversing it again. |
| 63: | * |
| 64: | * Only for callbacks whose result and side effects do not depend on |
| 65: | * where in the traversed type, or how many times, the type occurs. |
| 66: | * |
| 67: | * @param TypeTraverserCallable|callable(Type $type, callable(Type): Type $traverse): Type $cb |
| 68: | */ |
| 69: | public static function mapMemoized(Type $type, TypeTraverserCallable|callable $cb): Type |
| 70: | { |
| 71: | $self = new self($cb); |
| 72: | $self->memo = []; |
| 73: | |
| 74: | $traverser = $self->mapInternal($type); |
| 75: | $self->memo = null; |
| 76: | return $traverser; |
| 77: | } |
| 78: | |
| 79: | /** @param TypeTraverserCallable|callable(Type $type, callable(Type): Type $traverse): Type $cb */ |
| 80: | private function __construct(TypeTraverserCallable|callable $cb) |
| 81: | { |
| 82: | if ($cb instanceof TypeTraverserCallable) { |
| 83: | $this->cb = static fn (Type $type, callable $traverse): Type => $cb->traverse($type, $traverse); |
| 84: | } else { |
| 85: | $this->cb = $cb; |
| 86: | } |
| 87: | } |
| 88: | |
| 89: | /** @internal */ |
| 90: | public function mapInternal(Type $type): Type |
| 91: | { |
| 92: | if ($this->memo === null) { |
| 93: | return ($this->cb)($type, [$this, 'traverseInternal']); |
| 94: | } |
| 95: | |
| 96: | $id = spl_object_id($type); |
| 97: | if (isset($this->memo[$id])) { |
| 98: | return $this->memo[$id][1]; |
| 99: | } |
| 100: | |
| 101: | $result = ($this->cb)($type, [$this, 'traverseInternal']); |
| 102: | $this->memo[$id] = [$type, $result]; |
| 103: | |
| 104: | return $result; |
| 105: | } |
| 106: | |
| 107: | /** @internal */ |
| 108: | public function traverseInternal(Type $type): Type |
| 109: | { |
| 110: | return $type->traverse([$this, 'mapInternal']); |
| 111: | } |
| 112: | |
| 113: | } |
| 114: |