io.prestosql.metadata

Class SignatureBinder

java.lang.Object

io.prestosql.metadata.SignatureBinder

public class SignatureBinder
extends Object

Determines whether, and how, a callsite matches a generic function signature. Which is equivalent to finding assignments for the variables in the generic signature, such that all of the function's declared parameters are super types of the corresponding arguments, and also satisfy the declared constraints (such as a given type parameter must bind to an orderable type)

This implementation has made assumptions. When any of the assumptions is not satisfied, it will fail loudly.

• A type cannot have both type parameter and literal parameter.
• A literal parameter cannot be be used across types. see checkNoLiteralVariableUsageAcrossTypes(TypeSignature, Map).

Here are some known implementation limitations:

• Binding signature (decimal(x,2))boolean with arguments decimal(1,0) fails. It should produce decimal(3,1).

Constructor Summary

Constructors

Constructor and Description
SignatureBinder(TypeManager typeManager, Signature declaredSignature, boolean allowCoercion)

Method Summary

Modifier and Type	Method and Description
static List<TypeSignature>	applyBoundVariables(List<TypeSignature> typeSignatures, BoundVariables boundVariables)
static Signature	applyBoundVariables(Signature signature, BoundVariables boundVariables, int arity)
static TypeSignature	applyBoundVariables(TypeSignature typeSignature, BoundVariables boundVariables)
Optional<Signature>	bind(List<? extends TypeSignatureProvider> actualArgumentTypes)
Optional<Signature>	bind(List<? extends TypeSignatureProvider> actualArgumentTypes, Type actualReturnType)
Optional<BoundVariables>	bindVariables(List<? extends TypeSignatureProvider> actualArgumentTypes)
Optional<BoundVariables>	bindVariables(List<? extends TypeSignatureProvider> actualArgumentTypes, Type actualReturnType)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

SignatureBinder

public SignatureBinder(TypeManager typeManager,
                       Signature declaredSignature,
                       boolean allowCoercion)

Method Detail

bind

public Optional<Signature> bind(List<? extends TypeSignatureProvider> actualArgumentTypes)

bind

public Optional<Signature> bind(List<? extends TypeSignatureProvider> actualArgumentTypes,
                                Type actualReturnType)

bindVariables

public Optional<BoundVariables> bindVariables(List<? extends TypeSignatureProvider> actualArgumentTypes)

bindVariables

public Optional<BoundVariables> bindVariables(List<? extends TypeSignatureProvider> actualArgumentTypes,
                                              Type actualReturnType)

applyBoundVariables

public static Signature applyBoundVariables(Signature signature,
                                            BoundVariables boundVariables,
                                            int arity)

applyBoundVariables

public static List<TypeSignature> applyBoundVariables(List<TypeSignature> typeSignatures,
                                                      BoundVariables boundVariables)

applyBoundVariables

public static TypeSignature applyBoundVariables(TypeSignature typeSignature,
                                                BoundVariables boundVariables)