To.java

/*
  To.java

  (c) 2010-2014 Edward Swartz

  All rights reserved. This program and the accompanying materials
  are made available under the terms of the Eclipse Public License v1.0
  which accompanies this distribution, and is available at
  http://www.eclipse.org/legal/epl-v10.html
 */
package v9t9.tools.forthcomp.words;

import v9t9.tools.forthcomp.AbortException;
import v9t9.tools.forthcomp.HostContext;
import v9t9.tools.forthcomp.ISemantics;
import v9t9.tools.forthcomp.ITargetWord;
import v9t9.tools.forthcomp.IWord;
import v9t9.tools.forthcomp.LocalVariableTriple;
import v9t9.tools.forthcomp.TargetContext;

/**
 * Placeholder for local used in a colon-colon def
 * @author ejs
 *
 */
public class To extends BaseWord {
	/**
	 * 
	 */
	public To() {
		setCompilationSemantics(new ISemantics() {
			
			public void execute(HostContext hostContext, TargetContext targetContext)
					throws AbortException {
				String name = hostContext.readToken();
				
				LocalVariableTriple triple = ((ITargetWord) targetContext.getLatest()).getEntry().findLocal(name);
				if (triple != null) {
					targetContext.buildToLocal(triple.var.getIndex());
					return;
				}
				
				IWord word = targetContext.find(name);
				if (word == null)
					throw hostContext.abort(name + "?");
				
				if (word instanceof TargetValue) {
					targetContext.markHostExecutionUnsupported();
					targetContext.buildToValue(hostContext, (TargetValue) word);
				} else if (word instanceof TargetDefer) {
					targetContext.markHostExecutionUnsupported();
					targetContext.buildToRomDefer(hostContext, (TargetDefer) word);
				} else {
					throw hostContext.abort("cannot handle " + name);
				}
				
				if (getEntry() != null)
					getEntry().use();
			}
		});
		
		setExecutionSemantics(new ISemantics() {
			
			public void execute(HostContext hostContext, TargetContext targetContext)
					throws AbortException {
				String name = hostContext.readToken();
				
				IWord word = targetContext.find(name);
				if (word == null)
					throw hostContext.abort(name + "?");
				
				if (word instanceof TargetValue) {
					((TargetValue) word).setValue(targetContext, hostContext.popData());
				} else if (word instanceof TargetDefer) {
					targetContext.setDeferTarget((TargetDefer) word, hostContext.popData());
				} else {
					throw hostContext.abort("cannot handle " + name);
				}
			}
		});
	}

	@Override
	public boolean isCompilerWord() {
		return true;
	}
}