Changeset 405dbb3 for src/Tuples/TupleAssignment.cpp

Timestamp:

Jun 7, 2024, 4:53:25 PM (4 weeks ago)

Author:

Andrew Beach <ajbeach@…>

Branches:

master

Children:

0188539c

Parents:

bf64de3

Message:

Noticing that a function could have an early exit to save a level of indentation lead to a larger refactor. Slight code improvements besides the formatting change.

File:

• src/Tuples/TupleAssignment.cpp (modified) (1 diff)

src/Tuples/TupleAssignment.cpp

@@ -241 +241 @@
         ResolvExpr::CandidateFinder & crntFinder;
         std::string fname;
-        std::unique_ptr< Matcher > matcher;
 
 public:
         TupleAssignSpotter( ResolvExpr::CandidateFinder & f )
-        : crntFinder( f ), fname(), matcher() {}
-
-        // Find left- and right-hand-sides for mass or multiple assignment.
+        : crntFinder( f ), fname() {}
+
+        /// Find left- and right-hand-sides for mass or multiple assignment.
         void spot(
                 const ast::UntypedExpr * expr, std::vector< ResolvExpr::CandidateFinder > & args
-        ) {
-                if ( auto op = expr->func.as< ast::NameExpr >() ) {
-                        // Skip non-assignment functions.
-                        if ( !CodeGen::isCtorDtorAssign( op->name ) ) return;
-                        fname = op->name;
-
-                        // Handled by CandidateFinder if applicable (both odd cases).
-                        if ( args.empty() || ( 1 == args.size() && CodeGen::isAssignment( fname ) ) ) {
-                                return;
-                        }
-
-                        // Look over all possible left-hand-side.
-                        for ( ResolvExpr::CandidateRef & lhsCand : args[0] ) {
-                                // Skip non-tuple LHS.
-                                if ( !refToTuple( lhsCand->expr ) ) continue;
-
-                                // Explode is aware of casts - ensure every LHS
-                                // is sent into explode with a reference cast.
-                                if ( !lhsCand->expr.as< ast::CastExpr >() ) {
-                                        lhsCand->expr = new ast::CastExpr(
-                                                lhsCand->expr, new ast::ReferenceType( lhsCand->expr->result ) );
+        );
+        /// Wrapper around matcher.match.
+        void match( Matcher & matcher );
+};
+
+void TupleAssignSpotter::spot(
+        const ast::UntypedExpr * expr, std::vector< ResolvExpr::CandidateFinder > & args
+) {
+        // Skip non-"assignment" functions.
+        auto op = expr->func.as< ast::NameExpr >();
+        if ( nullptr == op || !CodeGen::isCtorDtorAssign( op->name ) ) return;
+
+        // Handled by CandidateFinder if applicable (both odd cases).
+        if ( args.empty() || ( 1 == args.size() && CodeGen::isAssignment( op->name ) ) ) {
+                return;
+        }
+
+        fname = op->name;
+
+        // Look over all possible left-hand-side.
+        for ( ResolvExpr::CandidateRef & lhsCand : args[0] ) {
+                // Skip non-tuple LHS.
+                if ( !refToTuple( lhsCand->expr ) ) continue;
+
+                // Explode is aware of casts - ensure every LHS
+                // is sent into explode with a reference cast.
+                if ( !lhsCand->expr.as< ast::CastExpr >() ) {
+                        lhsCand->expr = new ast::CastExpr(
+                                lhsCand->expr, new ast::ReferenceType( lhsCand->expr->result ) );
+                }
+
+                // Explode the LHS so that each field of a tuple-valued expr is assigned.
+                ResolvExpr::CandidateList lhs;
+                explode( *lhsCand, crntFinder.context.symtab, back_inserter(lhs), true );
+                for ( ResolvExpr::CandidateRef & cand : lhs ) {
+                        // Each LHS value must be a reference - some come in
+                        // with a cast, if not just cast to reference here.
+                        if ( !cand->expr->result.as< ast::ReferenceType >() ) {
+                                cand->expr = new ast::CastExpr(
+                                        cand->expr, new ast::ReferenceType( cand->expr->result ) );
+                        }
+                }
+
+                if ( 1 == args.size() ) {
+                        // Mass default-initialization/destruction.
+                        ResolvExpr::CandidateList rhs{};
+                        MassAssignMatcher matcher( *this, expr->location, lhs, rhs );
+                        match( matcher );
+                } else if ( 2 == args.size() ) {
+                        for ( const ResolvExpr::CandidateRef & rhsCand : args[1] ) {
+                                ResolvExpr::CandidateList rhs;
+                                if ( isTuple( rhsCand->expr ) ) {
+                                        // Multiple assignment:
+                                        explode( *rhsCand, crntFinder.context.symtab, back_inserter( rhs ), true );
+                                        MultipleAssignMatcher matcher( *this, expr->location, lhs, rhs );
+                                        match( matcher );
+                                } else {
+                                        // Mass assignment:
+                                        rhs.emplace_back( rhsCand );
+                                        MassAssignMatcher matcher( *this, expr->location, lhs, rhs );
+                                        match( matcher );
                                 }
-
-                                // Explode the LHS so that each field of a tuple-valued expr is assigned.
-                                ResolvExpr::CandidateList lhs;
-                                explode( *lhsCand, crntFinder.context.symtab, back_inserter(lhs), true );
-                                for ( ResolvExpr::CandidateRef & cand : lhs ) {
-                                        // Each LHS value must be a reference - some come in
-                                        // with a cast, if not just cast to reference here.
-                                        if ( !cand->expr->result.as< ast::ReferenceType >() ) {
-                                                cand->expr = new ast::CastExpr(
-                                                        cand->expr, new ast::ReferenceType( cand->expr->result ) );
-                                        }
-                                }
-
-                                if ( 1 == args.size() ) {
-                                        // Mass default-initialization/destruction.
-                                        ResolvExpr::CandidateList rhs{};
-                                        matcher.reset( new MassAssignMatcher( *this, expr->location, lhs, rhs ) );
-                                        match();
-                                } else if ( 2 == args.size() ) {
-                                        for ( const ResolvExpr::CandidateRef & rhsCand : args[1] ) {
-                                                ResolvExpr::CandidateList rhs;
-                                                if ( isTuple( rhsCand->expr ) ) {
-                                                        // Multiple assignment:
-                                                        explode( *rhsCand, crntFinder.context.symtab, back_inserter( rhs ), true );
-                                                        matcher.reset(
-                                                                new MultipleAssignMatcher( *this, expr->location, lhs, rhs ) );
-                                                } else {
-                                                        // Mass assignment:
-                                                        rhs.emplace_back( rhsCand );
-                                                        matcher.reset(
-                                                                new MassAssignMatcher( *this, expr->location, lhs, rhs ) );
-                                                }
-                                                match();
-                                        }
-                                } else {
-                                        // Expand all possible RHS possibilities.
-                                        std::vector< ResolvExpr::CandidateList > rhsCands;
-                                        combos(
-                                                std::next( args.begin(), 1 ), args.end(), back_inserter( rhsCands ) );
-                                        for ( const ResolvExpr::CandidateList & rhsCand : rhsCands ) {
-                                                // Multiple assignment:
-                                                ResolvExpr::CandidateList rhs;
-                                                explode( rhsCand, crntFinder.context.symtab, back_inserter( rhs ), true );
-                                                matcher.reset(
-                                                        new MultipleAssignMatcher( *this, expr->location, lhs, rhs ) );
-                                                match();
-                                        }
-                                }
-                        }
-                }
-        }
-
-        void match() {
-                assert( matcher );
-
-                std::vector< ast::ptr< ast::Expr > > newAssigns = matcher->match();
-
-                if ( !( matcher->lhs.empty() && matcher->rhs.empty() ) ) {
-                        // If both LHS and RHS are empty than this is the empty tuple
-                        // case, wherein it's okay for newAssigns to be empty. Otherwise,
-                        // return early so that no new candidates are generated.
-                        if ( newAssigns.empty() ) return;
-                }
-
-                ResolvExpr::CandidateList crnt;
-                // Now resolve new assignments.
-                for ( const ast::Expr * expr : newAssigns ) {
-                        PRINT(
-                                std::cerr << "== resolving tuple assign ==" << std::endl;
-                                std::cerr << expr << std::endl;
-                        )
-
-                        ResolvExpr::CandidateFinder finder( crntFinder.context, matcher->env );
-                        finder.allowVoid = true;
-
-                        try {
-                                finder.find( expr, ResolvExpr::ResolveMode::withAdjustment() );
-                        } catch (...) {
-                                // No match is not failure, just that this tuple assignment is invalid.
-                                return;
-                        }
-
-                        ResolvExpr::CandidateList & cands = finder.candidates;
-                        assert( 1 == cands.size() );
-                        assert( cands.front()->expr );
-                        crnt.emplace_back( std::move( cands.front() ) );
-                }
-
-                // extract expressions from the assignment candidates to produce a list of assignments
-                // that together form a sigle candidate
-                std::vector< ast::ptr< ast::Expr > > solved;
-                for ( ResolvExpr::CandidateRef & cand : crnt ) {
-                        solved.emplace_back( cand->expr );
-                        matcher->combineState( *cand );
-                }
-
-                crntFinder.candidates.emplace_back( std::make_shared< ResolvExpr::Candidate >(
-                        new ast::TupleAssignExpr(
-                                matcher->location, std::move( solved ), std::move( matcher->tmpDecls ) ),
-                        std::move( matcher->env ), std::move( matcher->open ), std::move( matcher->need ),
-                        ResolvExpr::sumCost( crnt ) + matcher->baseCost ) );
-        }
-};
+                        }
+                } else {
+                        // Expand all possible RHS possibilities.
+                        std::vector< ResolvExpr::CandidateList > rhsCands;
+                        combos(
+                                std::next( args.begin(), 1 ), args.end(), back_inserter( rhsCands ) );
+                        for ( const ResolvExpr::CandidateList & rhsCand : rhsCands ) {
+                                // Multiple assignment:
+                                ResolvExpr::CandidateList rhs;
+                                explode( rhsCand, crntFinder.context.symtab, back_inserter( rhs ), true );
+                                MultipleAssignMatcher matcher( *this, expr->location, lhs, rhs );
+                                match( matcher );
+                        }
+                }
+        }
+}
+
+void TupleAssignSpotter::match( TupleAssignSpotter::Matcher & matcher ) {
+        std::vector< ast::ptr< ast::Expr > > newAssigns = matcher.match();
+
+        if ( !( matcher.lhs.empty() && matcher.rhs.empty() ) ) {
+                // If both LHS and RHS are empty than this is the empty tuple
+                // case, wherein it's okay for newAssigns to be empty. Otherwise,
+                // return early so that no new candidates are generated.
+                if ( newAssigns.empty() ) return;
+        }
+
+        ResolvExpr::CandidateList crnt;
+        // Now resolve new assignments.
+        for ( const ast::Expr * expr : newAssigns ) {
+                PRINT(
+                        std::cerr << "== resolving tuple assign ==" << std::endl;
+                        std::cerr << expr << std::endl;
+                )
+
+                ResolvExpr::CandidateFinder finder( crntFinder.context, matcher.env );
+                finder.allowVoid = true;
+
+                try {
+                        finder.find( expr, ResolvExpr::ResolveMode::withAdjustment() );
+                } catch (...) {
+                        // No match is not failure, just that this tuple assignment is invalid.
+                        return;
+                }
+
+                ResolvExpr::CandidateList & cands = finder.candidates;
+                assert( 1 == cands.size() );
+                assert( cands.front()->expr );
+                crnt.emplace_back( std::move( cands.front() ) );
+        }
+
+        // extract expressions from the assignment candidates to produce a list of assignments
+        // that together form a sigle candidate
+        std::vector< ast::ptr< ast::Expr > > solved;
+        for ( ResolvExpr::CandidateRef & cand : crnt ) {
+                solved.emplace_back( cand->expr );
+                matcher.combineState( *cand );
+        }
+
+        crntFinder.candidates.emplace_back( std::make_shared< ResolvExpr::Candidate >(
+                new ast::TupleAssignExpr(
+                        matcher.location, std::move( solved ), std::move( matcher.tmpDecls ) ),
+                std::move( matcher.env ), std::move( matcher.open ), std::move( matcher.need ),
+                ResolvExpr::sumCost( crnt ) + matcher.baseCost ) );
+}
 
 } // anonymous namespace