Function is

packages/effect/src/SchemaParser.ts:148–150

(schema: S)

 * @since 3.10.0
 */
export function is<S extends Schema.Constraint>(schema: S): <I>(input: I) => input is I & S["Type"] {
  return _is<S["Type"]>(schema.ast)
}

/** @internal */
export function _is<T>(ast: SchemaAST.AST) {