jodd.csselly.selector.PseudoFunctionExpression Maven / Gradle / Ivy
// Copyright (c) 2003-present, Jodd Team (http://jodd.org)
// All rights reserved.
//
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// modification, are permitted provided that the following conditions are met:
//
// 1. Redistributions of source code must retain the above copyright notice,
// this list of conditions and the following disclaimer.
//
// 2. Redistributions in binary form must reproduce the above copyright
// notice, this list of conditions and the following disclaimer in the
// documentation and/or other materials provided with the distribution.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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package jodd.csselly.selector;
import jodd.csselly.CSSellyException;
import jodd.util.StringPool;
import jodd.util.StringUtil;
/**
* {@link PseudoFunction Pseudo function expression}, in form: an + b.
*/
public class PseudoFunctionExpression {
protected final int a;
protected final int b;
public PseudoFunctionExpression(String expression) {
expression = StringUtil.removeChars(expression, "+ \t\n\r\n");
if (expression.equals("odd")) {
a = 2;
b = 1;
} else if (expression.equals("even")) {
a = 2;
b = 0;
} else {
int nndx = expression.indexOf('n');
if (nndx != -1) {
String aVal = expression.substring(0, nndx).trim();
if (aVal.length() == 0) {
a = 1;
} else {
if (aVal.equals(StringPool.DASH)) {
a = -1;
} else {
a = parseInt(aVal);
}
}
String bVal = expression.substring(nndx + 1);
if (bVal.length() == 0) {
b = 0;
} else {
b = parseInt(bVal);
}
} else {
a = 0;
b = parseInt(expression);
}
}
}
/**
* Parses int value or throws CSSellyException on failure.
*/
protected int parseInt(final String value) {
try {
return Integer.parseInt(value);
} catch (NumberFormatException nfex) {
throw new CSSellyException(nfex);
}
}
/**
* Returns a value of the function expression.
*/
public int getValueA() {
return a;
}
/**
* Returns b value of the function expression.
*/
public int getValueB() {
return b;
}
/**
* Matches expression with the value.
*/
public boolean match(final int value) {
if (a == 0) {
return value == b;
}
if (a > 0) {
if (value < b) {
return false;
}
return (value - b) % a == 0;
}
if (value > b) {
return false;
}
return (b - value) % (-a) == 0;
}
}