/*
* Copyright (C) 2010 Google Inc.
*
* 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.clearsilver.jsilver.functions.string;
import com.google.clearsilver.jsilver.functions.NonEscapingFunction;
import com.google.clearsilver.jsilver.values.Value;
import static com.google.clearsilver.jsilver.values.Value.literalConstant;
import static com.google.clearsilver.jsilver.values.Value.literalValue;
import static java.lang.Math.max;
import static java.lang.Math.min;
/**
* Returns the string slice starting at start and ending at end, similar to the Python slice
* operator.
*/
public class SliceFunction extends NonEscapingFunction {
/**
* @param args 1 string values then 2 numeric values (start and end).
* @return Sliced string
*/
public Value execute(Value... args) {
Value stringValue = args[0];
Value startValue = args[1];
Value endValue = args[2];
String string = stringValue.asString();
int start = startValue.asNumber();
int end = endValue.asNumber();
int length = string.length();
if (start < 0) {
start += max(-start, length);
if (end == 0) {
end = length;
}
}
if (end < 0) {
end += length;
}
end = min(end, length);
if (end < start) {
return literalConstant("", args[0]);
}
return literalValue(string.substring(start, end), stringValue.getEscapeMode(), stringValue
.isPartiallyEscaped()
|| startValue.isPartiallyEscaped() || endValue.isPartiallyEscaped());
}
}