From b80d7cb8d52e1975058302edbe968987c1b8574f Mon Sep 17 00:00:00 2001
From: Martin Zak <zakmart1@fit.cvut.cz>
Date: Sun, 17 Nov 2013 17:07:04 +0100
Subject: [PATCH] Adds LeftRegularGrammar
---
alib/src/grammar/LeftRegularGrammar.cpp | 62 +++++++++++++++++++++++++
alib/src/grammar/LeftRegularGrammar.h | 24 ++++++++++
examples/grammar/leftRegular.xml | 46 ++++++++++++++++++
3 files changed, 132 insertions(+)
create mode 100644 alib/src/grammar/LeftRegularGrammar.cpp
create mode 100644 alib/src/grammar/LeftRegularGrammar.h
create mode 100644 examples/grammar/leftRegular.xml
diff --git a/alib/src/grammar/LeftRegularGrammar.cpp b/alib/src/grammar/LeftRegularGrammar.cpp
new file mode 100644
index 0000000000..d5e93ee179
--- /dev/null
+++ b/alib/src/grammar/LeftRegularGrammar.cpp
@@ -0,0 +1,62 @@
+/*
+ * LeftRegularGrammar.cpp
+ *
+ * Created on: Nov 17, 2013
+ * Author: martin
+ */
+
+#include "LeftRegularGrammar.h"
+
+namespace grammar {
+
+bool LeftRegularGrammar::isValidRule(const Rule& rule) const {
+ return checkLeftSide(rule.getLeftSide()) && checkRightSide(rule.getRightSide());
+}
+
+bool LeftRegularGrammar::checkLeftSide(const list<Symbol>& leftSide) const {
+ if (leftSide.size() != 1) {
+ return false;
+ }
+
+ if (nonTerminalSymbols.find(leftSide.front()) == nonTerminalSymbols.end()) {
+ return false;
+ }
+
+ return true;
+}
+
+bool LeftRegularGrammar::checkRightSide(const list<Symbol>& rightSide) const {
+ if (rightSide.size() == 0) {
+ return true;
+ } else if (rightSide.size() == 1) {
+ const Symbol& symbol = rightSide.front();
+
+ //check epsilon
+ if (symbol.getSymbol() == "") {
+ return true;
+ }
+
+ //check that symbol exists
+ return ((terminalSymbols.find(symbol) != terminalSymbols.end())
+ || (nonTerminalSymbols.find(symbol) != nonTerminalSymbols.end()));
+ } else {
+ //check if first symbol is nonterminal
+ list<Symbol>::const_iterator symbol = rightSide.begin();
+ if (nonTerminalSymbols.find(*symbol) == nonTerminalSymbols.end()) {
+ return false;
+ }
+
+ symbol++;
+
+ //check if following symbols are terminal
+ for (; symbol != rightSide.end(); symbol++) {
+ if (terminalSymbols.find(*symbol) == terminalSymbols.end()) {
+ return false;
+ }
+ }
+
+ return true;
+ }
+}
+
+} /* namespace grammar */
diff --git a/alib/src/grammar/LeftRegularGrammar.h b/alib/src/grammar/LeftRegularGrammar.h
new file mode 100644
index 0000000000..37d71be653
--- /dev/null
+++ b/alib/src/grammar/LeftRegularGrammar.h
@@ -0,0 +1,24 @@
+/*
+ * LeftRegularGrammar.h
+ *
+ * Created on: Nov 17, 2013
+ * Author: martin
+ */
+
+#ifndef LEFTREGULARGRAMMAR_H_
+#define LEFTREGULARGRAMMAR_H_
+
+#include "Grammar.h"
+
+namespace grammar {
+
+class LeftRegularGrammar : public Grammar {
+private:
+ bool checkLeftSide(const list<Symbol>& leftSide) const;
+ bool checkRightSide(const list<Symbol>& rightSide) const;
+protected:
+ bool isValidRule(const Rule& rule) const;
+};
+
+} /* namespace grammar */
+#endif /* LEFTREGULARGRAMMAR_H_ */
diff --git a/examples/grammar/leftRegular.xml b/examples/grammar/leftRegular.xml
new file mode 100644
index 0000000000..f1ab4aa2e9
--- /dev/null
+++ b/examples/grammar/leftRegular.xml
@@ -0,0 +1,46 @@
+<grammar>
+ <nonTerminalSymbols>
+ <symbol>S</symbol>
+ <symbol>A</symbol>
+ </nonTerminalSymbols>
+
+ <terminalSymbols>
+ <symbol>a</symbol>
+ <symbol>b</symbol>
+ </terminalSymbols>
+
+ <rules>
+ <rule>
+ <leftSide>
+ <symbol>S</symbol>
+ </leftSide>
+
+ <rightSide>
+ <symbol>A</symbol>
+ </rightSide>
+ </rule>
+ <rule>
+ <leftSide>
+ <symbol>A</symbol>
+ </leftSide>
+
+ <rightSide>
+ <symbol>a</symbol>
+ </rightSide>
+ </rule>
+ <rule>
+ <leftSide>
+ <symbol>A</symbol>
+ </leftSide>
+ <rightSide>
+ <symbol>A</symbol>
+ <symbol>b</symbol>
+ <symbol>b</symbol>
+ <symbol>b</symbol>
+ </rightSide>
+ </rule>
+ </rules>
+
+ <startSymbol>S</startSymbol>
+
+</grammar>
--
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