diff --git a/alib2data/src/grammar/ContextFree/EpsilonFreeCFG.cpp b/alib2data/src/grammar/ContextFree/EpsilonFreeCFG.cpp
index cccf6eca7c41401d9c55417e794bf497fb7a062a..d0facd7c198874b447527027449e146c680b2879 100644
--- a/alib2data/src/grammar/ContextFree/EpsilonFreeCFG.cpp
+++ b/alib2data/src/grammar/ContextFree/EpsilonFreeCFG.cpp
@@ -64,17 +64,8 @@ bool EpsilonFreeCFG::removeNonterminalSymbol(const alphabet::Symbol& symbol) {
bool EpsilonFreeCFG::addRule(const alphabet::Symbol& leftHandSide, const std::vector<alphabet::Symbol>& rightHandSide) {
int rSize = rightHandSide.size();
- if(leftHandSide == initialSymbol && rSize == 0) {
- for(const auto& rule : rules) {
- for(const auto& ruleRHS : rule.second) {
- if(any_of(ruleRHS.begin(), ruleRHS.end(), [&](const alphabet::Symbol& symbol) { return initialSymbol == symbol; })) {
- throw GrammarException("Initial symbol " + (std::string) initialSymbol + "used on right hand side of already existing rule");
- }
- }
- }
-
- generatesEpsilon = true;
- return rules[leftHandSide].insert(rightHandSide).second;
+ if(rSize == 0) {
+ throw GrammarException("Epsilon rule is not allowed");
} else {
if(!nonterminalAlphabet.count(leftHandSide))
throw GrammarException("Rule must rewrite nonterminal symbol");
@@ -82,8 +73,6 @@ bool EpsilonFreeCFG::addRule(const alphabet::Symbol& leftHandSide, const std::ve
for(const alphabet::Symbol& symbol : rightHandSide) {
if(terminalAlphabet.find(symbol) == terminalAlphabet.end() && nonterminalAlphabet.find(symbol) == nonterminalAlphabet.end())
throw GrammarException("Symbol \"" + (std::string) symbol.getSymbol() + "\" is not neither terminal nor nonterminal symbol");
- if(generatesEpsilon && symbol == initialSymbol)
- throw GrammarException("Initial symbol is already allowed to be rewritten to epsilon");
}
return rules[leftHandSide].insert(rightHandSide).second;
@@ -95,20 +84,23 @@ const std::map<alphabet::Symbol, std::set<std::vector<alphabet::Symbol>>> Epsilo
}
bool EpsilonFreeCFG::removeRule(const alphabet::Symbol& leftHandSide, const std::vector<alphabet::Symbol>& rightHandSide) {
- int rSize = rightHandSide.size();
-
- if(leftHandSide == initialSymbol && rSize == 0) {
- generatesEpsilon = false;
- }
return rules[leftHandSide].erase(rightHandSide);
}
+void EpsilonFreeCFG::setGeneratesEpsilon(bool genEps) {
+ generatesEpsilon = genEps;
+}
+
+bool EpsilonFreeCFG::getGeneratesEpsilon() const {
+ return generatesEpsilon;
+}
+
bool EpsilonFreeCFG::operator==(const GrammarBase& other) const {
return other == *this;
}
bool EpsilonFreeCFG::operator==(const EpsilonFreeCFG& other) const {
- return this->nonterminalAlphabet == other.nonterminalAlphabet && this->terminalAlphabet == other.terminalAlphabet && this->initialSymbol == other.initialSymbol && this->rules == other.rules;
+ return this->nonterminalAlphabet == other.nonterminalAlphabet && this->terminalAlphabet == other.terminalAlphabet && this->initialSymbol == other.initialSymbol && this->rules == other.rules && this->generatesEpsilon == other.generatesEpsilon;
}
void EpsilonFreeCFG::operator>>(std::ostream& out) const {
@@ -117,6 +109,7 @@ void EpsilonFreeCFG::operator>>(std::ostream& out) const {
<< "terminalAlphabet = " << terminalAlphabet
<< "initialSymbol = " << initialSymbol
<< "rules = " << rules
+ << "generatesEpsilon = " << generatesEpsilon
<< ")";
}
diff --git a/alib2data/src/grammar/ContextFree/EpsilonFreeCFG.h b/alib2data/src/grammar/ContextFree/EpsilonFreeCFG.h
index 44d31bd50dd2cf20463586823d26521f2972f529..149d0c65ed7304a0d262513289e712d2d07ee07f 100644
--- a/alib2data/src/grammar/ContextFree/EpsilonFreeCFG.h
+++ b/alib2data/src/grammar/ContextFree/EpsilonFreeCFG.h
@@ -40,6 +40,9 @@ public:
bool removeNonterminalSymbol(const alphabet::Symbol& symbol);
+ void setGeneratesEpsilon(bool genEps);
+ bool getGeneratesEpsilon() const;
+
virtual bool operator==(const GrammarBase& other) const;
virtual bool operator==(const EpsilonFreeCFG& other) const;
diff --git a/alib2data/src/grammar/GrammarFromXMLParser.cpp b/alib2data/src/grammar/GrammarFromXMLParser.cpp
index ede304e5002ccf09a7a80fef9db42eeaef051fda..72727df7e7af493794aa93efc071d9c42648a9a1 100644
--- a/alib2data/src/grammar/GrammarFromXMLParser.cpp
+++ b/alib2data/src/grammar/GrammarFromXMLParser.cpp
@@ -211,6 +211,9 @@ EpsilonFreeCFG GrammarFromXMLParser::parseEpsilonFreeCFG(std::list<sax::Token>&
parseRules(input, grammar);
+ bool generatesEpsilon = parseGeneratesEpsilon(input);
+ grammar.setGeneratesEpsilon(generatesEpsilon);
+
popToken(input, sax::Token::TokenType::END_ELEMENT, "EpsilonFreeCFG");
return grammar;
}
diff --git a/alib2data/src/grammar/GrammarToXMLComposer.cpp b/alib2data/src/grammar/GrammarToXMLComposer.cpp
index e87ff418fbc5c681d614160eee512889123c2010..a012f95cf991a1cbcf0bd2a1ef46ddeed19f8f16 100644
--- a/alib2data/src/grammar/GrammarToXMLComposer.cpp
+++ b/alib2data/src/grammar/GrammarToXMLComposer.cpp
@@ -126,6 +126,7 @@ std::list<sax::Token> GrammarToXMLComposer::compose(const EpsilonFreeCFG& gramma
composeTerminalAlphabet(out, grammar.getTerminalAlphabet());
composeInitialSymbol(out, grammar.getInitialSymbol());
composeRules(out, grammar);
+ composeGeneratesEpsilon(out, grammar.getGeneratesEpsilon());
out.push_back(sax::Token("EpsilonFreeCFG", sax::Token::TokenType::END_ELEMENT));
return out;
diff --git a/alib2data/test-src/grammar/GrammarTest.cpp b/alib2data/test-src/grammar/GrammarTest.cpp
index d3dbb5fc62203c14d778a42fd33f5cfb1f466b81..bf3bffea275fc5e6fa27fe93cc01ae484660fd8c 100644
--- a/alib2data/test-src/grammar/GrammarTest.cpp
+++ b/alib2data/test-src/grammar/GrammarTest.cpp
@@ -170,6 +170,36 @@ void GrammarTest::testContextFreeParser() {
grammar::GrammarFromXMLParser parser;
grammar::LG grammar2 = parser.parseLG(tokens2);
+ CPPUNIT_ASSERT( grammar == grammar2 );
+ }
+ }
+ {
+ grammar::EpsilonFreeCFG grammar(alphabet::Symbol(alphabet::LabeledSymbol(label::Label(label::IntegerLabel(1)))));
+
+ grammar.addNonterminalSymbol(alphabet::Symbol(alphabet::LabeledSymbol(label::Label(label::IntegerLabel(1)))));
+ grammar.addNonterminalSymbol(alphabet::Symbol(alphabet::LabeledSymbol(label::Label(label::IntegerLabel(2)))));
+ grammar.addNonterminalSymbol(alphabet::Symbol(alphabet::LabeledSymbol(label::Label(label::IntegerLabel(3)))));
+ grammar.addTerminalSymbol(alphabet::Symbol(alphabet::LabeledSymbol(label::Label(label::StringLabel("a")))));
+ grammar.addTerminalSymbol(alphabet::Symbol(alphabet::LabeledSymbol(label::Label(label::StringLabel("b")))));
+ grammar.setGeneratesEpsilon(true);
+
+ grammar.addRule(alphabet::Symbol(alphabet::LabeledSymbol(label::Label(label::IntegerLabel(1)))), std::vector<alphabet::Symbol> {alphabet::Symbol(alphabet::LabeledSymbol(label::Label(label::StringLabel("a")))), alphabet::Symbol(alphabet::LabeledSymbol(label::Label(label::IntegerLabel(2))))});
+ grammar.addRule(alphabet::Symbol(alphabet::LabeledSymbol(label::Label(label::IntegerLabel(2)))), std::vector<alphabet::Symbol> {alphabet::Symbol(alphabet::LabeledSymbol(label::Label(label::StringLabel("b")))), alphabet::Symbol(alphabet::LabeledSymbol(label::Label(label::IntegerLabel(3))))});
+ grammar.addRule(alphabet::Symbol(alphabet::LabeledSymbol(label::Label(label::IntegerLabel(1)))), std::vector<alphabet::Symbol> {alphabet::Symbol(alphabet::LabeledSymbol(label::Label(label::IntegerLabel(3))))});
+ grammar.addRule(alphabet::Symbol(alphabet::LabeledSymbol(label::Label(label::IntegerLabel(1)))), std::vector<alphabet::Symbol> {alphabet::Symbol(alphabet::LabeledSymbol(label::Label(label::StringLabel("a")))), alphabet::Symbol(alphabet::LabeledSymbol(label::Label(label::StringLabel("a")))), alphabet::Symbol(alphabet::LabeledSymbol(label::Label(label::StringLabel("a")))), alphabet::Symbol(alphabet::LabeledSymbol(label::Label(label::IntegerLabel(2))))});
+
+ CPPUNIT_ASSERT( grammar == grammar );
+ {
+ grammar::GrammarToXMLComposer composer;
+ std::list<sax::Token> tokens = composer.compose(grammar);
+ std::string tmp;
+ sax::SaxComposeInterface::printMemory(tmp, tokens);
+
+ std::list<sax::Token> tokens2;
+ sax::SaxParseInterface::parseMemory(tmp, tokens2);
+ grammar::GrammarFromXMLParser parser;
+ grammar::EpsilonFreeCFG grammar2 = parser.parseEpsilonFreeCFG(tokens2);
+
CPPUNIT_ASSERT( grammar == grammar2 );
}
}