namespace.java

一个JAVA编写的简单编译器

package ast;


public class NameSpace {
  private java.util.Hashtable objects = null;
  private java.util.Vector vobjects = null;
  private NameSpace parent = null;
  
 /**
 * setup and link to one new namespace.  
 *
 * @param parent parent-namespace
 */ 
  public NameSpace (NameSpace parent) {
    this.parent = parent;
    objects = new java.util.Hashtable ();
    vobjects = new java.util.Vector ();
  }
  
  private String name = null;
 /**
 * put Name
 *
 * @param name the name is namespace
 */ 
  public void setName (String name) {
    this.name = name;
  }
  public String getName () {
    return name;
  }
 /**
 * enter one Object in namespace
 */ 
  public void addObject (ast.declaration.JSubObject obj) {
    String key = obj.getName();
    Object o = objects.get (key);
    if (o == null) {
      objects.put (key, obj);
      vobjects.addElement (obj);
      obj.setParent (this);
    }
    else 
      util.Error.e1 ("name already defined " + key);
  }
  
 /**
 * find one Object in Namespace
 *
 * @return null or the location of Object
 */ 
  public ast.declaration.JSubObject getObject (String key) {
    return (ast.declaration.JSubObject)objects.get (key);
  }
  
 /**
 * amount All Object in namespace
 *
 * @return the Vektor with Object
 */ 
  public java.util.Vector getObjects () {
    return vobjects;
  }
  
 /**
 * number the definition Object amount
 *
 * @return number of definition Object
 */ 
  public int getNoOfLocals () {
    return objects.size ();
  }
  
 /**
 * display all Object
 *
 */ 
  public void dump () {
    for (int i = 0; i < vobjects.size (); i++) {
      ast.declaration.JSubObject oe = (ast.declaration.JSubObject)vobjects.elementAt (i);
      oe .dump ("");
    }
  }

 /**
 * generate XML for this namespace 
 *
 * @param p displaycurrent
 * @param prefix insert the row to the display 
 */
  public void genXML (java.io.PrintStream p, String prefix) {
    p.println (prefix + "<namespace>");
    for (int i = 0; i < vobjects.size (); i++) {
      ast.declaration.JSubObject oe = (ast.declaration.JSubObject)vobjects.elementAt (i);
      oe .genXML (p, prefix + "  ");
    }
    p.println (prefix + "</namespace>");
  }  
  
 /**
 * Codegeneration for the Namenspace.
 * Dispaly all static Variable and Codegeneration for Method.
 * 
 */ 
  public void codegen () {
    for (int i = 0; i < vobjects.size (); i++) {
      ast.declaration.JSubObject oe = (ast.declaration.JSubObject)vobjects.elementAt (i);
      if (oe instanceof ast.declaration.StaticVariable) {
        ast.declaration.StaticVariable variable = (ast.declaration.StaticVariable)oe;
        variable.codegen();
      }
    }
    
    for (int i = 0; i < vobjects.size (); i++) {
      ast.declaration.JSubObject oe = (ast.declaration.JSubObject)vobjects.elementAt (i);
      if (oe instanceof ast.declaration.StaticMethod) {
        ast.declaration.StaticMethod method = (ast.declaration.StaticMethod)oe;
        method.codegen();
      }
    }
  }
}