generatemanualconstruction.java

SRI international 发布的OAA框架软件

package com.sri.oaa2.icl;

/**
 * Given a well-formed String, s--that is, one for which IclTerm.fromString(true, s)
 * does not throw an exception--and where s contains no icldataq() type terms, this
 * class can be used to generate a new String which represents the manual construction
 * of the term represented by s. 
 * <p>
 * For example, calling getInstance().from("a") would result in the String
 * new IclStr("a")
 * This is most useful when you have a long String for which you currently call
 * IclTerm.fromString().  The reason is because calling fromString() is much
 * slower than using the equivalent constructor calls, due to the parsing
 * overhead.
 *
 * @author agno
 */
public class GenerateManualConstruction
{
  private static final GenerateManualConstruction singleton = new GenerateManualConstruction();

  GenerateManualConstruction() 
  {
  }

  /**
   * Generate a String representing the construction of the IclTerm represented
   * by s.  The construction will use Java constructors.
   *
   * @param s The String to convert
   * @return String a String which can be used to replace an existing call
   * to IclTerm.fromString
   */
  public String from(String s) 
  {
    IclTerm term = IclTerm.fromString(true, s);
    Traverse trav = new Traverse();
    trav.traverse(term);
    trav.getBuffer().delete(trav.getBuffer().length() - 2, trav.getBuffer().length());
    return trav.getBuffer().toString();
  }

  /**
   * Get an instance of this class.
   */
  public static GenerateManualConstruction getInstance() 
  {
    return singleton;
  }

  private class Traverse extends IclTermTraverser implements OaaPrologVocabTokenTypes
  {
    StringBuffer buffer = new StringBuffer();

    Traverse() 
    {
    }

    StringBuffer getBuffer() 
    {
      return buffer;
    }

    public boolean discover(IclTerm t) 
    {
      switch(t.getType()) {
      case OaaPrologVocabTokenTypes.LIST:
        this.getBuffer().append(
         "new IclList(Arrays.asList(new Object[] {");
        break;
      case OaaPrologVocabTokenTypes.GROUP:
        this.getBuffer().append(
         "new IclGroup(Arrays.asList(new Object[] {");
        break;
      case OaaPrologVocabTokenTypes.STRUCT:
        this.getBuffer().append("new IclStruct(");
        this.getBuffer().append("\"");
        this.getBuffer().append(((IclStruct)t).getFunctor());
        this.getBuffer().append("\"");
        this.getBuffer().append(
         ", Arrays.asList(new Object[] {");
        break;
      case OaaPrologVocabTokenTypes.INT:
        this.getBuffer().append("new IclInt(");
        this.getBuffer().append(((IclInt)t).toLong());
        this.getBuffer().append("L)");
        this.getBuffer().append(", ");
        break;
      case OaaPrologVocabTokenTypes.FLOAT:
        this.getBuffer().append("new IclFloat(");
        this.getBuffer().append(((IclFloat)t).toDouble());
        this.getBuffer().append(")");
        this.getBuffer().append(", ");
        break;
      case OaaPrologVocabTokenTypes.VAR:
        this.getBuffer().append("new IclVar(");
        this.getBuffer().append("\"");
        this.getBuffer().append(((IclVar)t).getName());
        this.getBuffer().append("\"");
        this.getBuffer().append(")");
        this.getBuffer().append(", ");
        break;
      case OaaPrologVocabTokenTypes.STR:
        this.getBuffer().append("new IclStr(");
        this.getBuffer().append("\"");
        this.getBuffer().append(((IclStr)t).toUnquotedString());
        this.getBuffer().append("\"");
        this.getBuffer().append(")");
        this.getBuffer().append(", ");
        break;
      case OaaPrologVocabTokenTypes.ICLDATAQ:
        throw new UnsupportedOperationException("GenerateManualConstruction won't work for IclDataQ");
      default:
        throw new UnsupportedOperationException("GenerateManualConstruction unknown type: " + t.getType());
      }
      return true;
    }
    
    public boolean finish(IclTerm t) 
    {
      switch(t.getType()) {
      case OaaPrologVocabTokenTypes.LIST:
        if(t.size() > 0) {
          this.getBuffer().delete(this.getBuffer().length() - 2, this.getBuffer().length());
        }
        this.getBuffer().append("}))");
        this.getBuffer().append(", ");
        break;
      case OaaPrologVocabTokenTypes.GROUP:
        if(t.size() > 0) {
          this.getBuffer().delete(this.getBuffer().length() - 2, this.getBuffer().length());
        }
        this.getBuffer().append("}), ");
        this.getBuffer().append("'");
        this.getBuffer().append(((IclGroup)t).getStarter());
        this.getBuffer().append("'");
        this.getBuffer().append(")");
        this.getBuffer().append(", ");
        break;
      case OaaPrologVocabTokenTypes.STRUCT:
        if(t.size() > 0) {
          this.getBuffer().delete(this.getBuffer().length() - 2, this.getBuffer().length());
        }
        this.getBuffer().append("}))");
        this.getBuffer().append(", ");
        break;
      default:
        // nothing
      }
      return true;
    }
  }
}