From 25db92b92cb5b7fefc0557d9013ed3489ad17b4e Mon Sep 17 00:00:00 2001
From: Jan Travnicek <Jan.Travnicek@fit.cvut.cz>
Date: Tue, 25 Sep 2018 08:24:20 +0200
Subject: [PATCH] simplify ToCNF algo
---
alib2algo/src/grammar/simplify/ToCNF.h | 41 +++++++-------------------
1 file changed, 11 insertions(+), 30 deletions(-)
diff --git a/alib2algo/src/grammar/simplify/ToCNF.h b/alib2algo/src/grammar/simplify/ToCNF.h
index 5e233c6a58..dd7d4d2839 100644
--- a/alib2algo/src/grammar/simplify/ToCNF.h
+++ b/alib2algo/src/grammar/simplify/ToCNF.h
@@ -130,41 +130,22 @@ grammar::CNF < TerminalSymbolType, ext::variant < TerminalSymbolType, Nontermin
template < class TerminalSymbolType, class NonterminalSymbolType >
void splitRule ( ext::vector < ext::variant < TerminalSymbolType, NonterminalSymbolType > > lhs, const ext::vector < ext::variant < TerminalSymbolType, NonterminalSymbolType > > & rhs, grammar::CNF < TerminalSymbolType, ext::vector < ext::variant < TerminalSymbolType, NonterminalSymbolType > > > & result ) {
- switch ( rhs.size ( ) ) {
- case 2: {
- ext::vector < ext::variant < TerminalSymbolType, NonterminalSymbolType > > left { rhs [ 0 ] };
- ext::vector < ext::variant < TerminalSymbolType, NonterminalSymbolType > > right { rhs [ 1 ] };
- result.addRule ( std::move ( lhs ), ext::make_pair ( std::move ( left ), std::move ( right ) ) );
- break;
- }
- case 3: {
- ext::vector < ext::variant < TerminalSymbolType, NonterminalSymbolType > > left { rhs [ 0 ] };
-
- ext::vector < ext::variant < TerminalSymbolType, NonterminalSymbolType > > right ( std::next ( rhs.begin ( ) ), rhs.end ( ) );
- if ( result.addNonterminalSymbol ( right ) )
- splitRule ( right, right, result );
+ ext::vector < ext::variant < TerminalSymbolType, NonterminalSymbolType > > left;
+ ext::vector < ext::variant < TerminalSymbolType, NonterminalSymbolType > > right;
- result.addRule ( std::move ( lhs ), ext::make_pair ( std::move ( left ), std::move ( right ) ) );
- break;
- }
- default: {
- ext::vector < ext::variant < TerminalSymbolType, NonterminalSymbolType > > left;
- for ( unsigned i = 0; i < rhs.size ( ) / 2; ++ i )
- left.push_back ( rhs [ i ] );
+ for ( unsigned i = 0; i < rhs.size ( ) / 2; ++ i )
+ left.push_back ( rhs [ i ] );
- if ( result.addNonterminalSymbol ( left ) )
- splitRule ( left, left, result );
+ if ( result.addNonterminalSymbol ( left ) && left.size ( ) > 1 )
+ splitRule ( left, left, result );
- ext::vector < ext::variant < TerminalSymbolType, NonterminalSymbolType > > right;
- for ( unsigned i = rhs.size ( ) / 2; i < rhs.size ( ); ++ i )
- right.push_back ( rhs [ i ] );
+ for ( unsigned i = rhs.size ( ) / 2; i < rhs.size ( ); ++ i )
+ right.push_back ( rhs [ i ] );
- if ( result.addNonterminalSymbol ( right ) )
- splitRule ( right, right, result );
+ if ( result.addNonterminalSymbol ( right ), right.size ( ) > 1 )
+ splitRule ( right, right, result );
- result.addRule ( std::move ( lhs ), ext::make_pair ( std::move ( left ), std::move ( right ) ) );
- }
- }
+ result.addRule ( std::move ( lhs ), ext::make_pair ( std::move ( left ), std::move ( right ) ) );
}
template < class T, class TerminalSymbolType = typename grammar::TerminalSymbolTypeOfGrammar < T >, class NonterminalSymbolType = typename grammar::NonterminalSymbolTypeOfGrammar < T > >
--
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