/*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.facebook.presto.metadata;
import com.facebook.presto.spi.function.OperatorType;
import com.facebook.presto.spi.type.Type;
import com.facebook.presto.spi.type.TypeSignature;
import com.fasterxml.jackson.annotation.JsonCreator;
import com.fasterxml.jackson.annotation.JsonProperty;
import com.google.common.base.Joiner;
import com.google.common.collect.ImmutableList;
import java.util.List;
import java.util.Objects;
import java.util.stream.Collectors;
import static com.facebook.presto.metadata.FunctionKind.SCALAR;
import static com.facebook.presto.metadata.FunctionRegistry.mangleOperatorName;
import static com.google.common.collect.ImmutableList.toImmutableList;
import static java.util.Objects.requireNonNull;
import static java.util.stream.Stream.concat;
public final class Signature
{
private final String name;
private final FunctionKind kind;
private final List<TypeVariableConstraint> typeVariableConstraints;
private final List<LongVariableConstraint> longVariableConstraints;
private final TypeSignature returnType;
private final List<TypeSignature> argumentTypes;
private final boolean variableArity;
@JsonCreator
public Signature(
@JsonProperty("name") String name,
@JsonProperty("kind") FunctionKind kind,
@JsonProperty("typeVariableConstraints") List<TypeVariableConstraint> typeVariableConstraints,
@JsonProperty("longVariableConstraints") List<LongVariableConstraint> longVariableConstraints,
@JsonProperty("returnType") TypeSignature returnType,
@JsonProperty("argumentTypes") List<TypeSignature> argumentTypes,
@JsonProperty("variableArity") boolean variableArity)
{
requireNonNull(name, "name is null");
requireNonNull(typeVariableConstraints, "typeVariableConstraints is null");
requireNonNull(longVariableConstraints, "longVariableConstraints is null");
this.name = name;
this.kind = requireNonNull(kind, "type is null");
this.typeVariableConstraints = ImmutableList.copyOf(typeVariableConstraints);
this.longVariableConstraints = ImmutableList.copyOf(longVariableConstraints);
this.returnType = requireNonNull(returnType, "returnType is null");
this.argumentTypes = ImmutableList.copyOf(requireNonNull(argumentTypes, "argumentTypes is null"));
this.variableArity = variableArity;
}
public Signature(String name, FunctionKind kind, TypeSignature returnType, TypeSignature... argumentTypes)
{
this(name, kind, returnType, ImmutableList.copyOf(argumentTypes));
}
public Signature(String name, FunctionKind kind, TypeSignature returnType, List<TypeSignature> argumentTypes)
{
this(name, kind, ImmutableList.of(), ImmutableList.of(), returnType, argumentTypes, false);
}
public static Signature internalOperator(OperatorType operator, Type returnType, List<? extends Type> argumentTypes)
{
return internalScalarFunction(mangleOperatorName(operator.name()), returnType.getTypeSignature(), argumentTypes.stream().map(Type::getTypeSignature).collect(toImmutableList()));
}
public static Signature internalOperator(OperatorType operator, TypeSignature returnType, TypeSignature... argumentTypes)
{
return internalOperator(operator, returnType, ImmutableList.copyOf(argumentTypes));
}
public static Signature internalOperator(OperatorType operator, TypeSignature returnType, List<TypeSignature> argumentTypes)
{
return internalScalarFunction(mangleOperatorName(operator.name()), returnType, argumentTypes);
}
public static Signature internalOperator(String name, TypeSignature returnType, List<TypeSignature> argumentTypes)
{
return internalScalarFunction(mangleOperatorName(name), returnType, argumentTypes);
}
public static Signature internalOperator(String name, TypeSignature returnType, TypeSignature... argumentTypes)
{
return internalScalarFunction(mangleOperatorName(name), returnType, ImmutableList.copyOf(argumentTypes));
}
public static Signature internalScalarFunction(String name, TypeSignature returnType, TypeSignature... argumentTypes)
{
return internalScalarFunction(name, returnType, ImmutableList.copyOf(argumentTypes));
}
public static Signature internalScalarFunction(String name, TypeSignature returnType, List<TypeSignature> argumentTypes)
{
return new Signature(name, SCALAR, ImmutableList.of(), ImmutableList.of(), returnType, argumentTypes, false);
}
public Signature withAlias(String name)
{
return new Signature(name, kind, typeVariableConstraints, longVariableConstraints, getReturnType(), getArgumentTypes(), variableArity);
}
@JsonProperty
public String getName()
{
return name;
}
@JsonProperty
public FunctionKind getKind()
{
return kind;
}
@JsonProperty
public TypeSignature getReturnType()
{
return returnType;
}
@JsonProperty
public List<TypeSignature> getArgumentTypes()
{
return argumentTypes;
}
@JsonProperty
public boolean isVariableArity()
{
return variableArity;
}
@JsonProperty
public List<TypeVariableConstraint> getTypeVariableConstraints()
{
return typeVariableConstraints;
}
@JsonProperty
public List<LongVariableConstraint> getLongVariableConstraints()
{
return longVariableConstraints;
}
@Override
public int hashCode()
{
return Objects.hash(name, kind, typeVariableConstraints, longVariableConstraints, returnType, argumentTypes, variableArity);
}
@Override
public boolean equals(Object obj)
{
if (this == obj) {
return true;
}
if (obj == null || getClass() != obj.getClass()) {
return false;
}
Signature other = (Signature) obj;
return Objects.equals(this.name, other.name) &&
Objects.equals(this.kind, other.kind) &&
Objects.equals(this.typeVariableConstraints, other.typeVariableConstraints) &&
Objects.equals(this.longVariableConstraints, other.longVariableConstraints) &&
Objects.equals(this.returnType, other.returnType) &&
Objects.equals(this.argumentTypes, other.argumentTypes) &&
Objects.equals(this.variableArity, other.variableArity);
}
@Override
public String toString()
{
List<String> allConstraints = concat(
typeVariableConstraints.stream().map(TypeVariableConstraint::toString),
longVariableConstraints.stream().map(LongVariableConstraint::toString))
.collect(Collectors.toList());
return name + (allConstraints.isEmpty() ? "" : "<" + Joiner.on(",").join(allConstraints) + ">") + "(" + Joiner.on(",").join(argumentTypes) + "):" + returnType;
}
/*
* similar to T extends MyClass<?...>, if Java supported varargs wildcards
*/
public static TypeVariableConstraint withVariadicBound(String name, String variadicBound)
{
return new TypeVariableConstraint(name, false, false, variadicBound);
}
public static TypeVariableConstraint comparableWithVariadicBound(String name, String variadicBound)
{
return new TypeVariableConstraint(name, true, false, variadicBound);
}
public static TypeVariableConstraint typeVariable(String name)
{
return new TypeVariableConstraint(name, false, false, null);
}
public static TypeVariableConstraint comparableTypeParameter(String name)
{
return new TypeVariableConstraint(name, true, false, null);
}
public static TypeVariableConstraint orderableWithVariadicBound(String name, String variadicBound)
{
return new TypeVariableConstraint(name, false, true, variadicBound);
}
public static TypeVariableConstraint orderableTypeParameter(String name)
{
return new TypeVariableConstraint(name, false, true, null);
}
public static LongVariableConstraint longVariableExpression(String variable, String expression)
{
return new LongVariableConstraint(variable, expression);
}
public static SignatureBuilder builder()
{
return new SignatureBuilder();
}
}