bundles/org.simantics.mapping/src/org/simantics/mapping/constraint/instructions/OrInstruction.java

   1 /*******************************************************************************
   2  * Copyright (c) 2007, 2010 Association for Decentralized Information Management
   3  * in Industry THTH ry.
   4  * All rights reserved. This program and the accompanying materials
   5  * are made available under the terms of the Eclipse Public License v1.0
   6  * which accompanies this distribution, and is available at
   7  * http://www.eclipse.org/legal/epl-v10.html
   8  *
   9  * Contributors:
  10  *     VTT Technical Research Centre of Finland - initial API and implementation
  11  *******************************************************************************/
  12 package org.simantics.mapping.constraint.instructions;
  13
  14 import org.simantics.db.ReadGraph;
  15 import org.simantics.db.exception.DatabaseException;
  16
  17 public class OrInstruction extends CombinedInstruction {
  18
  19         public OrInstruction(IInstruction... instructions) {
  20                 super(instructions);
  21         }
  22
  23         static class Continuation {
  24                 Object continuation;
  25                 int instructionId;
  26
  27                 public Continuation(Object continuation, int instructionId) {
  28                         this.continuation = continuation;
  29                         this.instructionId = instructionId;
  30                 }
  31         }
  32
  33         @Override
  34         public Object query(ReadGraph g, Object[] bindings) throws DatabaseException {
  35                 int instructionId;
  36                 for(instructionId=0;instructionId<instructions.length-1;++instructionId) {
  37                         if(DEBUG)
  38                                 System.out.println("OrInstruction.query " + instructionId + "/" + instructions.length);
  39                         Object continuation = instructions[instructionId].query(g, bindings);
  40                         if(continuation != IInstruction.FAILURE)
  41                                 return new Continuation(continuation, instructionId);
  42                 }
  43                 return instructions[instructionId].query(g, bindings);
  44         }
  45
  46         @Override
  47         public Object next(ReadGraph g, Object[] bindings, Object ret_) throws DatabaseException {
  48                 Continuation ret = (Continuation)ret_;
  49                 int instructionId = ret.instructionId;
  50                 Object continuation = ret.continuation;
  51
  52                 if(continuation != null) {
  53                         continuation = instructions[instructionId].next(g, bindings, continuation);
  54                         if(continuation != IInstruction.FAILURE) {
  55                                 ret.continuation = continuation;
  56                                 return ret;
  57                         }
  58                 }
  59
  60                 for(++instructionId;instructionId<instructions.length-1;++instructionId) {
  61                         continuation = instructions[instructionId].query(g, bindings);
  62                         if(continuation != IInstruction.FAILURE) {
  63                                 ret.continuation = continuation;
  64                                 ret.instructionId = instructionId;
  65                                 return ret;
  66                         }
  67                 }
  68                 return instructions[instructionId].query(g, bindings);
  69         }
  70
  71         @Override
  72         public void toString(StringBuilder b, int indent) {
  73                 b.append("(    ");
  74                 boolean first = true;
  75                 for(IInstruction inst : instructions) {
  76                         if(first)
  77                                 first = false;
  78                         else {
  79                                 b.append(";\n");
  80                                 for(int i=0;i<indent+1;++i)
  81                                         b.append(INDENTATION);
  82                         }
  83                         inst.toString(b, indent + 1);
  84                 }
  85                 b.append('\n');
  86                 for(int i=0;i<indent;++i)
  87                         b.append(INDENTATION);
  88                 b.append(")");
  89         }
  90 }