/interpreter/tags/at2dist091109/src/edu/vub/at/objects/natives/grammar/AGTabulation.java
Java | 111 lines | 47 code | 15 blank | 49 comment | 0 complexity | fb822e06fff10de33e9cadbbe53b2e2c MD5 | raw file
1/** 2 * AmbientTalk/2 Project 3 * AGTabulation.java created on 26-jul-2006 at 16:19:54 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.objects.ATContext; 32import edu.vub.at.objects.ATObject; 33import edu.vub.at.objects.grammar.ATExpression; 34import edu.vub.at.objects.grammar.ATTabulation; 35import edu.vub.at.objects.natives.NATMethodInvocation; 36import edu.vub.at.objects.natives.NATTable; 37import edu.vub.at.objects.natives.NATText; 38 39import java.util.Set; 40 41/** 42 * The native implementation of a tabulation AG element. 43 * Example: <tt>(o.tab)[x+1]</tt> 44 * 45 * @author tvcutsem 46 */ 47public final class AGTabulation extends AGExpression implements ATTabulation { 48 49 private final ATExpression tblExp_; 50 private final ATExpression idxExp_; 51 52 public AGTabulation(ATExpression tbl, ATExpression idx) { 53 tblExp_ = tbl; 54 idxExp_ = idx; 55 } 56 57 public ATExpression base_tableExpression() { return tblExp_; } 58 59 public ATExpression base_indexExpression() { return idxExp_; } 60 61 /** 62 * To evaluate a tabulation, evaluate the tabulation expression to a table, 63 * evaluate the index expression into a valid index, and then access the table at the given index slot. 64 * 65 * AGTBL(tbl,idx).eval(ctx) = tbl.eval(ctx).at(idx.eval(ctx)) 66 * 67 * @return the value of the indexed table slot. 68 */ 69 public ATObject meta_eval(ATContext ctx) throws InterpreterException { 70 ATObject col = tblExp_.meta_eval(ctx); 71 ATObject idx = idxExp_.meta_eval(ctx); 72 73 return col.meta_invoke(col, 74 new NATMethodInvocation( 75 AGSymbol.jAlloc("at"), 76 NATTable.of(idx), 77 NATTable.EMPTY)); 78 } 79 80 /** 81 * Quoting a tabulation results in a new quoted tabulation 82 * 83 * AGTBL(tbl,idx).quote(ctx) = AGTBL(tbl.quote(ctx),idx.quote(ctx)) 84 */ 85 public ATObject meta_quote(ATContext ctx) throws InterpreterException { 86 return new AGTabulation(tblExp_.meta_quote(ctx).asExpression(), 87 idxExp_.meta_quote(ctx).asExpression()); 88 } 89 90 public NATText meta_print() throws InterpreterException { 91 return NATText.atValue(tblExp_.meta_print().javaValue + "[" + 92 idxExp_.meta_print().javaValue + "]"); 93 } 94 95 /** 96 * FV(tblExp[idxExp]) = FV(tblExp) U FV(idxExp) 97 */ 98 public Set impl_freeVariables() throws InterpreterException { 99 Set fvTblExp = tblExp_.impl_freeVariables(); 100 fvTblExp.addAll(idxExp_.impl_freeVariables()); 101 return fvTblExp; 102 } 103 104 105 public Set impl_quotedFreeVariables() throws InterpreterException { 106 Set qfv = tblExp_.impl_quotedFreeVariables(); 107 qfv.addAll(idxExp_.impl_quotedFreeVariables()); 108 return qfv; 109 } 110 111}