/interpreter/tags/at2dist110511/src/edu/vub/at/objects/natives/grammar/AGSplice.java

  1/**
  2 * AmbientTalk/2 Project
  3 * AGSplice.java created on 1-aug-2006 at 21:12:15
  4 * (c) Programming Technology Lab, 2006 - 2007
  5 * Authors: Tom Van Cutsem & Stijn Mostinckx
  6 * 
  7 * Permission is hereby granted, free of charge, to any person
  8 * obtaining a copy of this software and associated documentation
  9 * files (the "Software"), to deal in the Software without
 10 * restriction, including without limitation the rights to use,
 11 * copy, modify, merge, publish, distribute, sublicense, and/or
 12 * sell copies of the Software, and to permit persons to whom the
 13 * Software is furnished to do so, subject to the following
 14 * conditions:
 15 *
 16 * The above copyright notice and this permission notice shall be
 17 * included in all copies or substantial portions of the Software.
 18 *
 19 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 20 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
 21 * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 22 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
 23 * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
 24 * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 25 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 26 * OTHER DEALINGS IN THE SOFTWARE.
 27 */
 28package edu.vub.at.objects.natives.grammar;
 29
 30import edu.vub.at.exceptions.InterpreterException;
 31import edu.vub.at.exceptions.XIllegalSplice;
 32import edu.vub.at.exceptions.XTypeMismatch;
 33import edu.vub.at.objects.ATContext;
 34import edu.vub.at.objects.ATObject;
 35import edu.vub.at.objects.grammar.ATExpression;
 36import edu.vub.at.objects.grammar.ATSplice;
 37import edu.vub.at.objects.natives.NATText;
 38import edu.vub.util.TempFieldGenerator;
 39
 40import java.util.Set;
 41
 42/**
 43 * @author tvc
 44 *
 45 * The native implementation of an AGSplice AG element.
 46 */
 47public class AGSplice extends AGExpression implements ATSplice {
 48
 49	private final ATExpression splExp_;
 50	
 51	public AGSplice(ATExpression exp) {
 52		splExp_ = exp;
 53	}
 54	
 55	public ATExpression base_expression() { return splExp_; }
 56
 57	/**
 58	 * A spliced element cannot be evaluated, but rather gives rise to an XIllegalSplice exception.
 59	 * This is because a splice should always be nested within either a formal parameter list or a table.
 60	 * 
 61	 * AGSPL(exp).eval(ctx) = ERROR
 62	 */
 63	public ATObject meta_eval(ATContext ctx) throws InterpreterException {
 64		throw new XIllegalSplice(splExp_);
 65	}
 66
 67	/**
 68	 * Quoting a splice means quoting its contained expression, and returning a new splice.
 69	 */
 70	public ATObject meta_quote(ATContext ctx) throws InterpreterException {
 71		return new AGSplice(splExp_.meta_quote(ctx).asExpression());
 72	}
 73
 74	public NATText meta_print() throws InterpreterException {
 75		return NATText.atValue("@"+ splExp_.meta_print().javaValue);
 76	}
 77	
 78	public NATText impl_asCode(TempFieldGenerator objectMap) throws InterpreterException {
 79		return this.impl_asUnquotedCode(objectMap);
 80	}
 81	
 82	public NATText impl_asUnquotedCode(TempFieldGenerator objectMap) throws InterpreterException {
 83		return NATText.atValue("@"+ splExp_.impl_asUnquotedCode(objectMap).javaValue);
 84	}
 85
 86	public boolean isSplice() { return true; }
 87	
 88	public ATSplice asSplice() throws XTypeMismatch {
 89		return this;
 90	}
 91	
 92	/**
 93	 * FV(@exp) = FV(exp)
 94	 */
 95	public Set impl_freeVariables() throws InterpreterException {
 96		return splExp_.impl_freeVariables();
 97	}
 98	
 99	
100	public Set impl_quotedFreeVariables() throws InterpreterException {
101		return splExp_.impl_quotedFreeVariables();
102	}
103
104}