Shapes

:::info[Note] This is a point-in-time snapshot of the API documentation from January 2026. Going forward, we will not be maintaining a public copy of these references, and recommend users to refer to the built-in signature helpers available in the Hack LSP instead for complete and up-to-date information. :::

Interface Synopsis

namespace HH;

abstract final class Shapes {...}

Public Methods

• ::at(shape() $shape, arraykey $index)
  Returns the value of the field $index of $shape, throws if the field is missing
• ::idx(shape(...) $shape, arraykey $index, mixed $default = NULL)
  Use Shapes::idx to retrieve a field value in a shape, when the key may or may not exist
• ::keyExists(shape() $shape, arraykey $index): bool
  Check if a field in shape exists
• ::removeKey<T as shape()>(inout darray $shape, arraykey $index): void
  Removes the $index field from the $shape (passed in as an inout argument)
• ::toArray(shape() $shape): darray<arraykey, mixed>
• ::toDict(shape() $shape): dict<arraykey, mixed>