souffle::ram::transform::CollapseFiltersTransformer Class Reference

Transforms consecutive filters into a single filter containing a conjunction. More...

#include <CollapseFilters.h>

Inheritance diagram for souffle::ram::transform::CollapseFiltersTransformer:

Collaboration diagram for souffle::ram::transform::CollapseFiltersTransformer:

Public Member Functions
bool	collapseFilters (Program &program)
	Collapse consecutive filter operations. More...
std::string	getName () const override
	@Brief get name of the transformer More...
Public Member Functions inherited from souffle::ram::transform::Transformer
bool	apply (TranslationUnit &translationUnit)
	@Brief apply the transformer to a translation unit @Param translationUnit that will be transformed. More...
virtual	~Transformer ()=default

Protected Member Functions
bool	transform (TranslationUnit &translationUnit) override
	@Brief transform the translation unit / used by apply @Param translationUnit that will be transformed. More...

Detailed Description

Transforms consecutive filters into a single filter containing a conjunction.

For example ..

QUERY
 ...
  IF C1
   IF C2
    ...

will be rewritten to

QUERY
 ...
  IF C1 /\ C2 then
   ...

Definition at line 52 of file CollapseFilters.h.

Member Function Documentation

collapseFilters()

bool souffle::ram::transform::CollapseFiltersTransformer::collapseFilters

(

Program &

program

)

Collapse consecutive filter operations.

Parameters

program

Program that is transformed

Returns

Flag showing whether the program has been changed by the transformation

Definition at line 35 of file CollapseFilters.cpp.

                                                                          {
                // true if two consecutive filters in loop nest found
                bool canCollapse = false;
 
                // storing conditions for collapsing
                VecOwn<Condition> conditions;
 
                const Filter* prevFilter = filter;
                conditions.emplace_back(filter->getCondition().clone());
                while (auto* nextFilter = dynamic_cast<Filter*>(&prevFilter->getOperation())) {
                    canCollapse = true;
                    conditions.emplace_back(nextFilter->getCondition().clone());
                    prevFilter = nextFilter;
                }
 
                if (canCollapse) {
                    changed = true;
                    node = mk<Filter>(toCondition(conditions), souffle::clone(&prevFilter->getOperation()),
                            prevFilter->getProfileText());
                }
            }
            node->apply(makeLambdaRamMapper(filterRewriter));
            return node;
        };
        const_cast<Query*>(&query)->apply(makeLambdaRamMapper(filterRewriter));
    });
    return changed;
}
 
}  // namespace souffle::ram::transform

References souffle::clone(), souffle::filter(), souffle::ram::NestedOperation::getOperation(), souffle::ram::NestedOperation::getProfileText(), and souffle::ram::toCondition().

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getName()

std::string souffle::ram::transform::CollapseFiltersTransformer::getName ( ) const

inlineoverridevirtual

@Brief get name of the transformer

Implements souffle::ram::transform::Transformer.

Definition at line 54 of file CollapseFilters.h.

         :
    bool transform(TranslationUnit& translationUnit) override {

transform()

bool souffle::ram::transform::CollapseFiltersTransformer::transform ( TranslationUnit &  translationUnit )

inlineoverrideprotectedvirtual

@Brief transform the translation unit / used by apply @Param translationUnit that will be transformed.

@Return flag reporting whether the RAM program has changed

Implements souffle::ram::transform::Transformer.

Definition at line 66 of file CollapseFilters.h.

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The documentation for this class was generated from the following files:

• ram/transform/CollapseFilters.h
• ram/transform/CollapseFilters.cpp