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55 lines
1.8 KiB
C++
55 lines
1.8 KiB
C++
/*
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* All or portions of this file Copyright (c) Amazon.com, Inc. or its affiliates or
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* its licensors.
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*
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* For complete copyright and license terms please see the LICENSE at the root of this
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* distribution (the "License"). All use of this software is governed by the License,
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* or, if provided, by the license below or the license accompanying this file. Do not
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* remove or modify any license notices. This file is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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*
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*/
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#pragma once
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#include <AzCore/std/any.h>
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#include <AzCore/RTTI/RTTI.h>
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#include <AzCore/std/string/string.h>
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#include <ExpressionEvaluation/ExpressionEngine/ExpressionTypes.h>
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#include <ExpressionEngine/InternalTypes.h>
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namespace ExpressionEvaluation
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{
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// Interface for expanding the available grammar for parsing.
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//
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// Must handle both parsing and execution.
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class ExpressionElementParser
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{
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public:
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AZ_CLASS_ALLOCATOR(ExpressionElementParser, AZ::SystemAllocator, 0);
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struct ParseResult
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{
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// Returns the number of characters that the parser wants to consume from the input text.
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size_t m_charactersConsumed = 0;
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ElementInformation m_element;
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};
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protected:
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ExpressionElementParser() = default;
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public:
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virtual ~ExpressionElementParser() = default;
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virtual ExpressionParserId GetParserId() const = 0;
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// Attempt to parse the specified element in the text at the specified offset.
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virtual ParseResult ParseElement(const AZStd::string& inputText, size_t offset) const = 0;
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// Evaluate the given token using the current evaluation stack.
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virtual void EvaluateToken(const ElementInformation& parseResult, ExpressionResultStack& evaluationStack) const = 0;
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};
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}
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