Types

A StackLang type is an element that represents the type of some other element. See the types page for more details. An EBNF definition for a type is given below.

base-type = "Boolean" | "Command" | "Number" | "String" | "Substack" | "Type" | "Any" ;

type = base-type | ("Substack", "(", type, ")") ;

Type-related Commands

Type Predicates

type? : Any -> Boolean
Produces true if element is a type.

specialized? : Any -> Boolean
Produces true if element is a specialized type.

base? : Any -> Boolean
Produces true if element is a base (unspecialized) type.

Type Operations

get-specialization : Type -> Type
Gets the specialization of the given type. Fails with a RuntimError if type is unspecialized.

add-specialization : Type Type -> Type
Adds the first type as a specialization onto the second type.

base : Type -> Type
Gets the base type of the given type. If type is unspecialized, produces the type itself.

check-type : Type Any -> Boolean
Produces true if element is of the given type.

typeof : Any -> Type
Produces the type of the element. Does not consider specializations.

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