/*
* Licensed to CRATE Technology GmbH ("Crate") under one or more contributor
* license agreements. See the NOTICE file distributed with this work for
* additional information regarding copyright ownership. Crate licenses
* this file to you 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.
*
* However, if you have executed another commercial license agreement
* with Crate these terms will supersede the license and you may use the
* software solely pursuant to the terms of the relevant commercial agreement.
*/
package io.crate.metadata;
import io.crate.analyze.symbol.Function;
import io.crate.analyze.symbol.Symbol;
import javax.annotation.Nullable;
/**
* Base interface for function implementations.
*/
public interface FunctionImplementation {
/**
* Provides meta information about this function implementation.
*/
FunctionInfo info();
/**
* Normalize a symbol into a simplified form.
* This may return the symbol as is if it cannot be normalized.
*
* @param transactionContext context which is shared across normalizeSymbol calls during a statement-lifecycle.
* This will only be present if normalizeSymbol is called on the handler node.
* normalizeSymbol calls during execution won't receive a StmtCtx
*/
default Symbol normalizeSymbol(Function function, @Nullable TransactionContext transactionContext){
return function;
}
}