| /* EqualityExpr.java -- |
| Copyright (C) 2004 Free Software Foundation, Inc. |
| |
| This file is part of GNU Classpath. |
| |
| GNU Classpath 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 2, or (at your option) |
| any later version. |
| |
| GNU Classpath is 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 GNU Classpath; see the file COPYING. If not, write to the |
| Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA |
| 02111-1307 USA. |
| |
| Linking this library statically or dynamically with other modules is |
| making a combined work based on this library. Thus, the terms and |
| conditions of the GNU General Public License cover the whole |
| combination. |
| |
| As a special exception, the copyright holders of this library give you |
| permission to link this library with independent modules to produce an |
| executable, regardless of the license terms of these independent |
| modules, and to copy and distribute the resulting executable under |
| terms of your choice, provided that you also meet, for each linked |
| independent module, the terms and conditions of the license of that |
| module. An independent module is a module which is not derived from |
| or based on this library. If you modify this library, you may extend |
| this exception to your version of the library, but you are not |
| obligated to do so. If you do not wish to do so, delete this |
| exception statement from your version. */ |
| |
| package gnu.xml.xpath; |
| |
| import java.util.Collection; |
| import java.util.Iterator; |
| import org.w3c.dom.Node; |
| |
| /** |
| * Boolean equality expression. |
| * |
| * @author <a href='mailto:dog@gnu.org'>Chris Burdess</a> |
| */ |
| final class EqualityExpr |
| extends Expr |
| { |
| |
| final Expr lhs; |
| final Expr rhs; |
| final boolean invert; |
| |
| EqualityExpr(Expr lhs, Expr rhs, boolean invert) |
| { |
| this.lhs = lhs; |
| this.rhs = rhs; |
| this.invert = invert; |
| } |
| |
| public Object evaluate(Node context, int pos, int len) |
| { |
| boolean val = evaluateImpl(context, pos, len); |
| if (invert) |
| { |
| return val ? Boolean.FALSE : Boolean.TRUE; |
| } |
| else |
| { |
| return val ? Boolean.TRUE : Boolean.FALSE; |
| } |
| } |
| |
| private boolean evaluateImpl(Node context, int pos, int len) |
| { |
| Object left = lhs.evaluate(context, pos, len); |
| Object right = rhs.evaluate(context, pos, len); |
| |
| /* |
| * If both objects to be compared are node-sets, then the comparison |
| * will be true if and only if there is a node in the first node-set and |
| * a node in the second node-set such that the result of performing the |
| * comparison on the string-values of the two nodes is true. |
| */ |
| boolean flns = left instanceof Collection; |
| boolean frns = right instanceof Collection; |
| if (flns && frns) |
| { |
| Collection lns = (Collection) left; |
| Collection rns = (Collection) right; |
| boolean all = true; |
| for (Iterator i = lns.iterator(); i.hasNext(); ) |
| { |
| Node ltest = (Node) i.next(); |
| for (Iterator j = rns.iterator(); j.hasNext(); ) |
| { |
| Node rtest = (Node) j.next(); |
| if (ltest == rtest || ltest.equals(rtest)) |
| { |
| // much shorter |
| if (!invert) |
| { |
| return true; |
| } |
| } |
| else if (stringValue(ltest).equals(stringValue(rtest))) |
| { |
| if (!invert) |
| { |
| return true; |
| } |
| } |
| else |
| { |
| all = false; |
| } |
| } |
| } |
| return false; |
| } |
| /* |
| * If one object to be compared is a node-set and the other is a number, |
| * then the comparison will be true if and only if there is a node in |
| * the node-set such that the result of performing the comparison on the |
| * number to be compared and on the result of converting the |
| * string-value of that node to a number using the number function is |
| * true. |
| */ |
| boolean fln = left instanceof Double; |
| boolean frn = right instanceof Double; |
| if ((flns && frn) || (frns && fln)) |
| { |
| Collection ns = flns ? (Collection) left : (Collection) right; |
| double n = fln ? ((Double) left).doubleValue() : |
| ((Double) right).doubleValue(); |
| boolean all = true; |
| for (Iterator i = ns.iterator(); i.hasNext(); ) |
| { |
| Node test = (Node) i.next(); |
| double nn = _number(context, stringValue(test)); |
| if (nn == n) |
| { |
| if (!invert) |
| { |
| return true; |
| } |
| } |
| else |
| { |
| all = false; |
| } |
| } |
| return invert ? all : false; |
| } |
| /* |
| * If one object to be compared is a node-set and the other is a |
| * string, then the comparison will be true if and only if there is a |
| * node in the node-set such that the result of performing the |
| * comparison on the string-value of the node and the other string is |
| * true. |
| */ |
| boolean fls = left instanceof String; |
| boolean frs = right instanceof String; |
| if ((flns && frs) || (frns && fls)) |
| { |
| Collection ns = flns ? (Collection) left : (Collection) right; |
| String s = fls ? (String) left : (String) right; |
| boolean all = true; |
| for (Iterator i = ns.iterator(); i.hasNext(); ) |
| { |
| Node test = (Node) i.next(); |
| if (stringValue(test).equals(s)) |
| { |
| if (!invert) |
| { |
| return true; |
| } |
| } |
| else |
| { |
| all = false; |
| } |
| } |
| return invert ? all : false; |
| } |
| /* |
| * If one object to be compared is a node-set and the other is a |
| * boolean, then the comparison will be true if and only if the result |
| * of performing the comparison on the boolean and on the result of |
| * converting the node-set to a boolean using the boolean function is |
| * true. |
| */ |
| boolean flb = left instanceof Boolean; |
| boolean frb = right instanceof Boolean; |
| if ((flns && frb) || (frns && flb)) |
| { |
| Collection ns = flns ? (Collection) left : (Collection) right; |
| boolean b = flb ? ((Boolean) left).booleanValue() : |
| ((Boolean) right).booleanValue(); |
| return _boolean(context, ns) == b; |
| } |
| /* |
| * If at least one object to be compared is a boolean, then each object |
| * to be compared is converted to a boolean as if by applying the |
| * boolean function. |
| */ |
| if (flb || frb) |
| { |
| boolean lb = flb ? ((Boolean) left).booleanValue() : |
| _boolean(context, left); |
| boolean rb = frb ? ((Boolean) right).booleanValue() : |
| _boolean(context, right); |
| return lb == rb; |
| } |
| /* |
| * Otherwise, if at least one object to be compared is |
| * a number, then each object to be compared is converted to a number as |
| * if by applying the number function. |
| */ |
| if (fln || frn) |
| { |
| double ln = fln ? ((Double) left).doubleValue() : |
| _number(context, left); |
| double rn = frn ? ((Double) right).doubleValue() : |
| _number(context, right); |
| return ln == rn; |
| } |
| /* |
| * Otherwise, both objects to be |
| * compared are converted to strings as if by applying the string |
| * function. |
| */ |
| String ls = fls ? (String) left : _string(context, left); |
| String rs = frs ? (String) right : _string(context, right); |
| return ls.equals(rs); |
| } |
| |
| public Expr clone(Object context) |
| { |
| return new EqualityExpr(lhs.clone(context), rhs.clone(context), invert); |
| } |
| |
| public String toString() |
| { |
| if (invert) |
| { |
| return lhs + " != " + rhs; |
| } |
| else |
| { |
| return lhs + " = " + rhs; |
| } |
| } |
| |
| } |
