Package net.hydromatic.morel.type

Class DataType

java.lang.Object

net.hydromatic.morel.type.BaseType

net.hydromatic.morel.type.ParameterizedType

net.hydromatic.morel.type.DataType

All Implemented Interfaces:

NamedType, Type

public class DataType
extends ParameterizedType

Algebraic type.

Nested Class Summary

Nested classes/interfaces inherited from interface net.hydromatic.morel.type.Type

Type.Key

Field Summary

Fields

Modifier and Type	Field	Description
final List<Type>	arguments
final Map<String,Type.Key>	typeConstructors

Fields inherited from class net.hydromatic.morel.type.ParameterizedType

moniker, name, parameterTypes

Fields inherited from class net.hydromatic.morel.type.BaseType

op

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	DataType(String name, String moniker, com.google.common.collect.ImmutableList<Type> arguments, com.google.common.collect.ImmutableMap<String,Type.Key> typeConstructors)	Creates a DataType.

Method Summary

Modifier and Type	Method	Description
<R> R	accept(TypeVisitor<R> typeVisitor)
Type	arg(int i)	Returns the ith type parameter.
DataType	copy(TypeSystem typeSystem, UnaryOperator<Type> transform)	Copies this type, applying a given transform to component types, and returning the original type if the component types are unchanged.
StringBuilder	describe(StringBuilder buf)	Writes out the definition of the datatype.
boolean	isCollection()	Whether this is a collection type (list or bag).
Keys.DataTypeKey	key()	Description of the type, e.g
boolean	specializes(Type type)	Whether this type is the same as, or a specialization of, a given type.
Map<String,Type>	typeConstructors(TypeSystem typeSystem)

Methods inherited from class net.hydromatic.morel.type.ParameterizedType

computeMoniker, moniker, name, toString

Methods inherited from class net.hydromatic.morel.type.BaseType

equals, hashCode, op

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface net.hydromatic.morel.type.Type

canCallArgOf, isFinite, isProgressive, op, substitute, unifyWith

Field Details

arguments

public final List<Type> arguments

typeConstructors

public final Map<String,Type.Key> typeConstructors

Constructor Details

DataType

protected DataType(String name,
 String moniker,
 com.google.common.collect.ImmutableList<Type> arguments,
 com.google.common.collect.ImmutableMap<String,Type.Key> typeConstructors)

Creates a DataType.

Called only from TypeSystem.dataTypes(List).

If the typeSystem argument is specified, canonizes the types inside type-constructors. This also allows temporary types (necessary while creating self-referential data types) to be replaced with real DataType instances.

During replacement, if a type matches placeholderType it is replaced with this. This allows cyclic graphs to be copied.

Method Details

key

public Keys.DataTypeKey key()

Description copied from interface: Type

Description of the type, e.g. "int", "int -> int", " NONE | SOME of 'a".

arg

public Type arg(int i)

Description copied from interface: Type

Returns the ith type parameter. Throws for types except ListType and DataType.

isCollection

public boolean isCollection()

Description copied from interface: Type

Whether this is a collection type (list or bag).

If a type is a collection type, arg(0) returns the element type.

accept

public <R> R accept(TypeVisitor<R> typeVisitor)

typeConstructors

public Map<String,Type> typeConstructors(TypeSystem typeSystem)

copy

public DataType copy(TypeSystem typeSystem,
 UnaryOperator<Type> transform)

Description copied from interface: Type

Copies this type, applying a given transform to component types, and returning the original type if the component types are unchanged.

describe

public StringBuilder describe(StringBuilder buf)

Writes out the definition of the datatype. For example,

 datatype ('a,'b) tree =
     Empty
   | Node of ('a,'b) tree * 'b * 'a * ('a,'b) tree
 

specializes

public boolean specializes(Type type)

Description copied from interface: Type

Whether this type is the same as, or a specialization of, a given type.

For example, bool specializes bool and 'a but does not specialize int or ('a, 'b).