content: /* Alloy Analyzer 4 -- Copyright (c) 2006-2009, Felix Chang
   *
   * Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files
   * (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify,
   * merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is
   * furnished to do so, subject to the following conditions:
   *
   * The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
   *
   * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
   * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
   * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF
   * OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
   */
  
  package edu.mit.csail.sdg.ast;
  
  import static edu.mit.csail.sdg.ast.Type.EMPTY;
  
  import java.util.ArrayList;
  import java.util.Collection;
  import java.util.List;
  
  import edu.mit.csail.sdg.alloy4.Err;
  import edu.mit.csail.sdg.alloy4.ErrorType;
  import edu.mit.csail.sdg.alloy4.ErrorWarning;
  import edu.mit.csail.sdg.alloy4.JoinableList;
  import edu.mit.csail.sdg.alloy4.Pos;
  
  /**
   * Immutable; represents an illegal relation join.
   * <p>
   * <b>Invariant:</b> this.type==EMPTY && this.errors.size()>0
   */
  
  public final class ExprBadJoin extends Expr {
  
      /** The left-hand-side expression. */
      public final Expr left;
  
      /** The right-hand-side expression. */
      public final Expr right;
  
      /** Caches the span() result. */
      private Pos       span = null;
  
      /** {@inheritDoc} */
      @Override
      public Pos span() {
          Pos p = span;
          if (p == null)
              span = (p = pos.merge(closingBracket).merge(right.span()).merge(left.span()));
          return p;
      }
  
      /** {@inheritDoc} */
      @Override
      public void toString(StringBuilder out, int indent) {
          if (indent < 0) {
              left.toString(out, -1);
              out.append('.');
              right.toString(out, -1);
          } else {
              for (int i = 0; i < indent; i++) {
                  out.append(' ');
              }
              out.append("ExprBadJoin:\n");
              left.toString(out, indent + 2);
              right.toString(out, indent + 2);
          }
      }
  
      /** Constructs an ExprBadJoin node. */
      private ExprBadJoin(Pos pos, Pos closingBracket, Expr left, Expr right, JoinableList<Err> errors) {
          super(pos, closingBracket, (left.ambiguous || right.ambiguous), EMPTY, 0, 0, errors);
          this.left = left;
          this.right = right;
      }
  
      /** Constructs an ExprBadJoin node. */
      public static Expr make(Pos pos, Pos closingBracket, Expr left, Expr right) {
          JoinableList<Err> errors = left.errors.make(right.errors);
          if (errors.isEmpty()) {
              StringBuilder sb = new StringBuilder("This cannot be a legal relational join where\nleft hand side is ");
              left.toString(sb, -1);
              sb.append(" (type = ").append(left.type).append(")\nright hand side is ");
              right.toString(sb, -1);
              sb.append(" (type = ").append(right.type).append(")\n");
              errors = errors.make(new ErrorType(pos, sb.toString()));
          }
          return new ExprBadJoin(pos, closingBracket, left, right, errors);
      }
  
      /** {@inheritDoc} */
      @Override
      public int getDepth() {
          int a = left.getDepth(), b = right.getDepth();
          if (a >= b)
              return 1 + a;
          else
              return 1 + b;
      }
  
      /** {@inheritDoc} */
      @Override
      public Expr resolve(Type t, Collection<ErrorWarning> warns) {
          return this;
      }
  
      /** {@inheritDoc} */
      @Override
      public final <T> T accept(VisitReturn<T> visitor) throws Err {
          return visitor.visit(this);
      }
  
      /** {@inheritDoc} */
      @Override
      public String getHTML() {
          return "<b>error</b> (parser or typechecker failed)";
      }
  
      /** {@inheritDoc} */
      @Override
      public List< ? extends Browsable> getSubnodes() {
          return new ArrayList<Browsable>(0);
      }
  }
  