Interface TypeDescriptor

All Known Implementing Classes:

TypeDescriptor.Parameterized, TypeDescriptor.Simple, TypeDescriptor.TypeVariable

public sealed interface TypeDescriptor
permits TypeDescriptor.Simple, TypeDescriptor.Parameterized, TypeDescriptor.TypeVariable

A recursive type descriptor that supports generic/parameterized types. Used on port definitions to express types like List, Map<String, Number>, or type variables like T that get resolved based on connections.

Nested Class Summary

Nested Classes

Modifier and Type	Interface	Description
static final record	TypeDescriptor.Parameterized	A parameterized type like List or Map<K, V>.
static final record	TypeDescriptor.Simple	A simple, non-parameterized type (e.g., NUMBER, STRING, BOT).
static final record	TypeDescriptor.TypeVariable	A type variable that gets bound during type inference.

Method Summary

Modifier and Type	Method	Description
PortType	baseType()	Returns the base PortType for backward compatibility.
String	displayString()	Returns a human-readable representation like "List" or "T".
boolean	hasTypeVariables()	Checks whether this descriptor contains any type variables.
static TypeDescriptor	list(TypeDescriptor elementType)	Creates a parameterized List type: List.
static TypeDescriptor	listOf(PortType elementType)	Convenience: List<Simple(elementType)>.
static TypeDescriptor	map(TypeDescriptor keyType, TypeDescriptor valueType)	Creates a parameterized Map type: Map<keyType, valueType>.
static TypeDescriptor	mapOf(PortType keyType, PortType valueType)	Convenience: Map<Simple(keyType), Simple(valueType)>.
static Map<String, TypeDescriptor>	newBindings()	Creates a fresh bindings map for unification.
TypeDescriptor	resolve(Map<String, TypeDescriptor> bindings)	Resolves type variables using the given bindings.
static TypeDescriptor	simple(PortType type)	Creates a simple (non-parameterized) type descriptor.
static TypeDescriptor	typeVar(String name)	Creates a type variable that gets resolved from connected ports.
static boolean	unify(TypeDescriptor a, TypeDescriptor b, Map<String, TypeDescriptor> bindings)	Attempts to unify two type descriptors, updating bindings for type variables.

Method Details

simple

static TypeDescriptor simple(PortType type)

Creates a simple (non-parameterized) type descriptor.

typeVar

static TypeDescriptor typeVar(String name)

Creates a type variable that gets resolved from connected ports. Type variables are scoped per node: each node instance has its own bindings.

list

static TypeDescriptor list(TypeDescriptor elementType)

Creates a parameterized List type: List.

map

static TypeDescriptor map(TypeDescriptor keyType,
 TypeDescriptor valueType)

Creates a parameterized Map type: Map<keyType, valueType>.

listOf

static TypeDescriptor listOf(PortType elementType)

Convenience: List<Simple(elementType)>.

mapOf

static TypeDescriptor mapOf(PortType keyType,
 PortType valueType)

Convenience: Map<Simple(keyType), Simple(valueType)>.

baseType

PortType baseType()

Returns the base PortType for backward compatibility. Simple returns its type, Parameterized returns its base, TypeVariable returns ANY.

displayString

String displayString()

Returns a human-readable representation like "List" or "T".

resolve

TypeDescriptor resolve(Map<String, TypeDescriptor> bindings)

Resolves type variables using the given bindings. Returns a new TypeDescriptor with all known variables replaced.

hasTypeVariables

boolean hasTypeVariables()

Checks whether this descriptor contains any type variables.

unify

static boolean unify(TypeDescriptor a,
 TypeDescriptor b,
 Map<String, TypeDescriptor> bindings)

Attempts to unify two type descriptors, updating bindings for type variables. Returns true if unification succeeds, false if the types are incompatible.

Unification rules:

• TypeVariable unifies with anything (binds the variable)
• Simple(ANY) unifies with anything
• Simple(A) unifies with Simple(B) if A == B or compatible via TypeCompatibility
• Parameterized(base, params) unifies with Parameterized(base2, params2) if base == base2 and all params unify pairwise

newBindings

static Map<String, TypeDescriptor> newBindings()

Creates a fresh bindings map for unification.