CumeDist.java

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//
//   http://www.apache.org/licenses/LICENSE-2.0
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package org.apache.doris.nereids.trees.expressions.functions.window;

import org.apache.doris.catalog.FunctionSignature;
import org.apache.doris.nereids.trees.expressions.Expression;
import org.apache.doris.nereids.trees.expressions.functions.AlwaysNotNullable;
import org.apache.doris.nereids.trees.expressions.shape.LeafExpression;
import org.apache.doris.nereids.trees.expressions.visitor.ExpressionVisitor;
import org.apache.doris.nereids.types.DoubleType;

import com.google.common.base.Preconditions;
import com.google.common.collect.ImmutableList;

import java.util.List;

/**
 * Window function: cume_dist()
 */
public class CumeDist extends WindowFunction implements AlwaysNotNullable, LeafExpression {

    public CumeDist() {
        super("cume_dist");
    }

    @Override
    public List<FunctionSignature> getSignatures() {
        return ImmutableList.of(FunctionSignature.ret(DoubleType.INSTANCE).args());
    }

    @Override
    public FunctionSignature searchSignature(List<FunctionSignature> signatures) {
        return signatures.get(0);
    }

    @Override
    public CumeDist withChildren(List<Expression> children) {
        Preconditions.checkArgument(children.size() == 0);
        return new CumeDist();
    }

    @Override
    public <R, C> R accept(ExpressionVisitor<R, C> visitor, C context) {
        return visitor.visitCumeDist(this, context);
    }
}