mirror of
https://github.com/octoleo/plantuml.git
synced 2024-06-02 00:20:49 +00:00
131 lines
2.9 KiB
Java
131 lines
2.9 KiB
Java
/* ========================================================================
|
|
* PlantUML : a free UML diagram generator
|
|
* ========================================================================
|
|
*
|
|
* (C) Copyright 2009-2020, Arnaud Roques
|
|
*
|
|
* Project Info: http://plantuml.com
|
|
*
|
|
* If you like this project or if you find it useful, you can support us at:
|
|
*
|
|
* http://plantuml.com/patreon (only 1$ per month!)
|
|
* http://plantuml.com/paypal
|
|
*
|
|
* This file is part of PlantUML.
|
|
*
|
|
* PlantUML is free software; you can redistribute it and/or modify it
|
|
* under the terms of the GNU General Public License as published by
|
|
* the Free Software Foundation, either version 3 of the License, or
|
|
* (at your option) any later version.
|
|
*
|
|
* PlantUML distributed in the hope that it will be useful, but
|
|
* WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
|
|
* or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public
|
|
* License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public
|
|
* License along with this library; if not, write to the Free Software
|
|
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
|
|
* USA.
|
|
*
|
|
*
|
|
* Original Author: Arnaud Roques
|
|
*
|
|
*
|
|
*/
|
|
package net.sourceforge.plantuml.preproc;
|
|
|
|
// http://stackoverflow.com/questions/3422673/evaluating-a-math-expression-given-in-string-form
|
|
public class EvalBoolean {
|
|
|
|
private final String str;
|
|
private int pos = -1;
|
|
private char ch;
|
|
private final Truth truth;
|
|
|
|
public EvalBoolean(String str, Truth truth) {
|
|
this.str = str;
|
|
this.truth = truth;
|
|
}
|
|
|
|
private void nextChar() {
|
|
pos++;
|
|
if (pos < str.length()) {
|
|
ch = str.charAt(pos);
|
|
} else {
|
|
ch = '\0';
|
|
}
|
|
}
|
|
|
|
private boolean eat(char charToEat) {
|
|
while (ch == ' ') {
|
|
nextChar();
|
|
}
|
|
if (ch == charToEat) {
|
|
nextChar();
|
|
return true;
|
|
}
|
|
return false;
|
|
}
|
|
|
|
private boolean parseExpression() {
|
|
boolean x = parseTerm();
|
|
while (true) {
|
|
if (eat('|')) {
|
|
eat('|');
|
|
x = x | parseTerm();
|
|
} else {
|
|
return x;
|
|
}
|
|
}
|
|
}
|
|
|
|
private boolean parseTerm() {
|
|
boolean x = parseFactor();
|
|
while (true) {
|
|
if (eat('&')) {
|
|
eat('&');
|
|
x = x & parseFactor();
|
|
} else {
|
|
return x;
|
|
}
|
|
}
|
|
}
|
|
|
|
private boolean parseFactor() {
|
|
if (eat('!')) {
|
|
return !(parseFactor());
|
|
}
|
|
|
|
final boolean x;
|
|
final int startPos = pos;
|
|
if (eat('(')) {
|
|
x = parseExpression();
|
|
eat(')');
|
|
} else if (isIdentifier()) {
|
|
while (isIdentifier()) {
|
|
nextChar();
|
|
}
|
|
final String func = str.substring(startPos, pos);
|
|
x = truth.isTrue(func);
|
|
} else {
|
|
throw new IllegalArgumentException("Unexpected: " + (char) ch);
|
|
}
|
|
|
|
return x;
|
|
}
|
|
|
|
private boolean isIdentifier() {
|
|
return ch == '_' || ch == '$' || Character.isLetterOrDigit(ch);
|
|
}
|
|
|
|
public boolean eval() {
|
|
nextChar();
|
|
final boolean x = parseExpression();
|
|
if (pos < str.length()) {
|
|
throw new IllegalArgumentException("Unexpected: " + (char) ch);
|
|
}
|
|
return x;
|
|
}
|
|
}
|