Class PHPStan\Type\TypeTraverser

Map a Type recursively

For every Type instance, the callback can return a new Type, and/or decide to traverse inner types or to ignore them.

The following example converts constant strings to objects, while preserving unions and intersections:

TypeTraverser::map($type, function (Type $type, callable $traverse): Type {
    if ($type instanceof UnionType || $type instanceof IntersectionType) {
        // Traverse inner types
        return $traverse($type);
    }
    if ($type instanceof ConstantStringType) {
        // Replaces the current type, and don't traverse
        return new ObjectType($type->getValue());
    }
    // Replaces the current type, and don't traverse
    return new MixedType();
});