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

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