Package io.trino.metadata

Class SignatureBinder

java.lang.Object

io.trino.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 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).

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	SignatureBinder.RelationshipType

Method Summary

Modifier and Type	Method	Description
static Signature	applyBoundVariables(Signature signature, FunctionBinding functionBinding, int arity)
static TypeSignature	applyBoundVariables(TypeSignature typeSignature, FunctionBinding functionBinding)
static List<TypeSignature>	applyBoundVariables(List<TypeSignature> typeSignatures, FunctionBinding functionBinding)
Optional<Signature>	bind(List<? extends TypeSignatureProvider> actualArgumentTypes)
Optional<Signature>	bind(List<? extends TypeSignatureProvider> actualArgumentTypes, Type actualReturnType)
static FunctionBinding	bindFunction(FunctionId functionId, Signature declaredSignature, BoundSignature boundSignature)
boolean	canBind(List<? extends TypeSignatureProvider> actualArgumentTypes)
boolean	canBind(List<? extends TypeSignatureProvider> actualArgumentTypes, TypeSignature actualReturnType)

Methods inherited from class java.lang.Object

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

Method Detail

bind

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

bind

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

canBind

public boolean canBind(List<? extends TypeSignatureProvider> actualArgumentTypes)

canBind

public boolean canBind(List<? extends TypeSignatureProvider> actualArgumentTypes,
                       TypeSignature actualReturnType)

applyBoundVariables

public static Signature applyBoundVariables(Signature signature,
                                            FunctionBinding functionBinding,
                                            int arity)

applyBoundVariables

public static List<TypeSignature> applyBoundVariables(List<TypeSignature> typeSignatures,
                                                      FunctionBinding functionBinding)

applyBoundVariables

public static TypeSignature applyBoundVariables(TypeSignature typeSignature,
                                                FunctionBinding functionBinding)

bindFunction

public static FunctionBinding bindFunction(FunctionId functionId,
                                           Signature declaredSignature,
                                           BoundSignature boundSignature)