// Copyright Verizon Media. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
package com.yahoo.tensor.functions;
import com.yahoo.tensor.Tensor;
import com.yahoo.tensor.TensorType;
import com.yahoo.tensor.evaluation.EvaluationContext;
import com.yahoo.tensor.evaluation.Name;
import com.yahoo.tensor.evaluation.TypeContext;
import java.util.Collections;
import java.util.Iterator;
import java.util.List;
import java.util.Objects;
/**
* The cell_cast tensor function creates a new tensor with the specified cell value type.
*
* @author lesters
*/
public class CellCast extends PrimitiveTensorFunction {
private final TensorFunction argument;
private final TensorType.Value valueType;
public CellCast(TensorFunction argument, TensorType.Value valueType) {
Objects.requireNonNull(argument, "The argument tensor cannot be null");
Objects.requireNonNull(valueType, "The value type cannot be null");
this.argument = argument;
this.valueType = valueType;
}
@Override
public List> arguments() { return Collections.singletonList(argument); }
@Override
public TensorFunction withArguments(List> arguments) {
if ( arguments.size() != 1)
throw new IllegalArgumentException("CellCast must have 1 argument, got " + arguments.size());
return new CellCast<>(arguments.get(0), valueType);
}
@Override
public PrimitiveTensorFunction toPrimitive() {
return new CellCast<>(argument.toPrimitive(), valueType);
}
@Override
public TensorType type(TypeContext context) {
return new TensorType(valueType, argument.type(context).dimensions());
}
@Override
public Tensor evaluate(EvaluationContext context) {
Tensor tensor = argument.evaluate(context);
if (tensor.type().valueType() == valueType) {
return tensor;
}
TensorType type = new TensorType(valueType, tensor.type().dimensions());
return cast(tensor, type);
}
private Tensor cast(Tensor tensor, TensorType type) {
Tensor.Builder builder = Tensor.Builder.of(type);
TensorType.Value fromValueType = tensor.type().valueType();
for (Iterator i = tensor.cellIterator(); i.hasNext(); ) {
Tensor.Cell cell = i.next();
if (fromValueType == TensorType.Value.FLOAT) {
builder.cell(cell.getKey(), cell.getFloatValue());
} else if (fromValueType == TensorType.Value.DOUBLE) {
builder.cell(cell.getKey(), cell.getDoubleValue());
} else {
builder.cell(cell.getKey(), cell.getValue());
}
}
return builder.build();
}
@Override
public String toString(ToStringContext context) {
return "cell_cast(" + argument.toString(context) + ", " + valueType + ")";
}
}