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// Copyright 2014 The Bazel Authors. All rights reserved.
//
// 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.google.devtools.common.options;
import com.google.devtools.common.options.Converters.BooleanConverter;
/**
* Converter that can convert both the standard set of boolean string values and enumerations. If
* there is an overlap in values, those from the underlying enumeration will be taken.
*
* <p>Note that for the flag to take one of its enum values on the command line, it must be of the
* form "--flag=value". That is, "--flag value" and "-f value" (if the flag has a short-form of "f")
* will result in "value" being left as residue on the command line. This maintains compatibility
* with boolean flags where "--flag true" and "-f true" also leave "true" as residue on the command
* line.
*/
public abstract class BoolOrEnumConverter<T extends Enum<T>> extends EnumConverter<T> {
private final T falseValue;
private final T trueValue;
/**
* You *must* implement a zero-argument constructor that delegates
* to this constructor, passing in the appropriate parameters. This
* comes from the base {@link EnumConverter} class.
*
* @param enumType The type of your enumeration; usually a class literal
* like MyEnum.class
* @param typeName The intuitive name of your enumeration, for example, the
* type name for CompilationMode might be "compilation mode".
* @param trueValue The enumeration value to associate with {@code true}.
* @param falseValue The enumeration value to associate with {@code false}.
*/
protected BoolOrEnumConverter(Class<T> enumType, String typeName, T trueValue, T falseValue) {
super(enumType, typeName);
this.trueValue = trueValue;
this.falseValue = falseValue;
}
@Override
public T convert(String input) throws OptionsParsingException {
try {
return super.convert(input);
} catch (OptionsParsingException eEnum) {
try {
BooleanConverter booleanConverter = new BooleanConverter();
boolean value = booleanConverter.convert(input);
return value ? trueValue : falseValue;
} catch (OptionsParsingException eBoolean) {
// TODO(b/111883901): Rethrowing the exception from the enum converter does not report the
// allowable boolean values.
throw eEnum;
}
}
}
}