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https://github.com/SSCLI/sscli_20021101
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yallie
48 lines
2.2 KiB
C#
48 lines
2.2 KiB
C#
// ==++==
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//
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//
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// Copyright (c) 2002 Microsoft Corporation. All rights reserved.
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//
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// The use and distribution terms for this software are contained in the file
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// named license.txt, which can be found in the root of this distribution.
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// By using this software in any fashion, you are agreeing to be bound by the
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// terms of this license.
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//
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// You must not remove this notice, or any other, from this software.
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//
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//
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// ==--==
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namespace Microsoft.JScript
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{
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using System;
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using System.Reflection;
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/*
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This interface is implemented by all objects taking part in a scope chain.
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The first method either returns the contained object of a with scope, or the global scope.
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The second method runs up the scope chain until it reaches a scope that comprises static variables, for example a module scope.
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The third method is used to find local declarations. This is used at compile time for error checking.
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The latter two methods are used to search the scope chain for a variable that could not be finally resolved at compile time.
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This happens when a function that contains an eval refers to a variable in outer scope. Since the eval may declare a local
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with the same name, it is not safe to do early binding to the outer scope variable. Rather than search the entire scope
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chain, these functions search only the part preceding the scope known to have such a variable. If they fail to find such an item
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the early bound code is invoked.
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There are two big advantages to doing this:
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1) Successful hashtable lookups (of strings) are much more expensive than unsuccessful lookups and should be avoided.
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2) StackFrames avoid allocating hash tables until a search is actually done on them. By avoiding the lookup
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we avoid the allocation and population of the hash table until it is really necessary.
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*/
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public interface IActivationObject{
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Object GetDefaultThisObject();
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GlobalScope GetGlobalScope(); //Never returns null.
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FieldInfo GetLocalField(String name);
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Object GetMemberValue(String name, int lexlevel);
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FieldInfo GetField(String name, int lexLevel);
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}
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}
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