/interpreter/tags/at_build150307/src/edu/vub/at/objects/ATClosure.java
Java | 111 lines | 10 code | 10 blank | 91 comment | 0 complexity | 5eed3be0dc058d72b6360f472e55816b MD5 | raw file
1/** 2 * AmbientTalk/2 Project 3 * ATClosure.java created on Jul 23, 2006 at 11:52:10 AM 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; 29 30import edu.vub.at.exceptions.InterpreterException; 31 32 33/** 34 * The public interface to a native AmbientTalk closure (a method + enclosing environment). 35 * 36 * Since ATMethods are always wrapped either at creation time (blocks) or during 37 * lookup (methods), ATClosures are by definition the only way methods and blocks 38 * can be encountered at the ambienttalk base level. Closures should respond to the 39 * base_apply method, which should trigger the invocation of their encapsulating method in the 40 * enclosed closure context. 41 * 42 * Closures are sometimes also 'abused' to simply represent blocks of source code whose 43 * body has to be evaluated not in the enclosed lexical context, but within the context 44 * of another object. To facilitate such use, a closure provides the method 'base_applyInScope' 45 * which will execute the enclosed method in the scope of the given object, rather than 46 * in the enclosed lexical context. 47 * 48 * @author smostinc 49 * @author tvcutsem 50 */ 51public interface ATClosure extends ATObject { 52 53 /** 54 * Structural access to the encapsulated method. 55 */ 56 public ATMethod base_getMethod() throws InterpreterException; 57 58 /** 59 * Structural access to the scope of the closure. 60 */ 61 public ATContext base_getContext() throws InterpreterException; 62 63 /** 64 * Applies the closure to the given arguments, already wrapped in a table. 65 * The enclosed method is executed in the context provided by the closure. 66 * 67 * @param args the already evaluated arguments, wrapped in a table 68 * @return the value of evaluating the method body in the context of the closure 69 */ 70 public ATObject base_apply(ATTable args) throws InterpreterException; 71 72 /** 73 * Applies the closure to the given arguments, already wrapped in a table. 74 * The enclodes method is executed in the context of the given object. The 75 * enclosed closure context is disregarded. 76 * 77 * The context provided by an object is always equal to: 78 * <tt>ctx(cur=object,self=object,super=object.dynamicParent)</tt> 79 * 80 * @param args the already evaluated arguments, wrapped in a table 81 * @param scope the object that will act as self and as lexically enclosing scope. 82 * @return the value of evaluating the method body in the context of the given object scope 83 */ 84 public ATObject base_applyInScope(ATTable args, ATObject scope) throws InterpreterException; 85 86 /** 87 * Allows AmbientTalk programmers to write 88 * { booleanCondition }.whileTrue: { body } 89 * which will execute body as long as the boolean condition evaluates to true. 90 */ 91 public ATObject base_whileTrue_(ATClosure body) throws InterpreterException; 92 93 /** 94 * { |quit| ... quit(val) ... }.escape() 95 * 96 * The escape control construct passes to its receiver block a function which 97 * when invoked, immediately transfers control back to the caller of escape, 98 * returning the value passed to quit. 99 * 100 * If no value is passed to quit, nil is returned instead. 101 * 102 * If quit is not invoked during the execution of the receiver block, 103 * the block terminates normally, with its normal return value. 104 * 105 * If quit is invoked at the point where the call to escape has already returned, 106 * either normally or via an exception or another escape call, 107 * invoking quit will raise an XIllegalOperation exception. 108 */ 109 public ATObject base_escape() throws InterpreterException; 110 111}