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32 lines
958 B
C++
32 lines
958 B
C++
#pragma once
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#include <Parsers/IAST.h>
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#include <Interpreters/InDepthNodeVisitor.h>
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namespace DB
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{
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class ASTFunction;
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/// Extract constant arguments out of aggregate functions from child functions
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/// 'sum(a * 2)' -> 'sum(a) * 2'
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/// Rewrites: sum([multiply|divide]) -> [multiply|divide](sum)
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/// [min|max|avg]([multiply|divide|plus|minus]) -> [multiply|divide|plus|minus]([min|max|avg])
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/// TODO: groupBitAnd, groupBitOr, groupBitXor
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/// TODO: better constant detection: f(const) is not detected as const.
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/// TODO: 'f((2 * n) * n)' -> '2 * f(n * n)'
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class ArithmeticOperationsInAgrFuncMatcher
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{
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public:
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struct Data {};
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static void visit(ASTPtr & ast, Data & data);
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static void visit(const ASTFunction &, ASTPtr & ast, Data & data);
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static bool needChildVisit(const ASTPtr & node, const ASTPtr & child);
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};
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using ArithmeticOperationsInAgrFuncVisitor = InDepthNodeVisitor<ArithmeticOperationsInAgrFuncMatcher, false>;
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}
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