org.neo4j.cypher.internal.expressions.functions.Reduce.scala Maven / Gradle / Ivy
/*
* Copyright (c) "Neo4j"
* Neo4j Sweden AB [https://neo4j.com]
*
* 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.
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package org.neo4j.cypher.internal.expressions.functions
import org.neo4j.cypher.internal.expressions.FunctionTypeSignature
import org.neo4j.cypher.internal.util.symbols.CTAny
import org.neo4j.cypher.internal.util.symbols.CTList
// this implementation exists only to handle the case where "reduce(x = 0, x in y : foo)" is parsed as a function invocation,
// rather than a ReduceExpression
case object Reduce extends Function {
def name = "reduce"
// TODO: Get specification formalized by CLG
override val signatures = Vector(
FunctionTypeSignature(
function = this,
names = Vector("accumulator", "variable"),
argumentTypes = Vector(CTAny, CTList(CTAny)),
outputType = CTAny,
description =
"Runs an expression against individual elements of a `LIST`, storing the result of the expression in an accumulator.",
category = Category.LIST,
overrideDefaultAsString = Some(
name + "(accumulator :: VARIABLE = initial :: ANY, variable :: VARIABLE IN list :: LIST | expression :: ANY) :: ANY"
)
)
)
}