diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/tree.cc | 116 | ||||
| -rw-r--r-- | src/utils.cc | 10 |
2 files changed, 77 insertions, 49 deletions
diff --git a/src/tree.cc b/src/tree.cc index 419a05c..f8c17ae 100644 --- a/src/tree.cc +++ b/src/tree.cc @@ -1,6 +1,8 @@ #include "tree.h" #include "exceptions.h" +#include <boost/optional.hpp> + #include <sstream> #include <limits> #include <stack> @@ -10,19 +12,24 @@ namespace { using SimpleParser::Node; - inline Node* topNode(const std::stack<Node*>& stack) { + inline boost::optional<Node*> top(const std::stack<Node*> stack) { if ( !stack.empty() ) { - return stack.top(); + return boost::make_optional<Node*>( + stack.top() + ); } else { - throw SimpleParser::operator_exception(); + return boost::optional<Node*>(); } } - inline Node* popNode(std::stack<Node*>& stack) { - Node*const tmp = topNode(stack); - stack.pop(); + inline boost::optional<Node*> pop(std::stack<Node*>& stack) { + if ( boost::optional<Node*> node{ top(stack) } ) { + stack.pop(); - return tmp; + return node; + } else { + return node; + } } } @@ -119,33 +126,44 @@ Node* Tree::buildTree(const std::string& term) { elementToken != TokenType::VALUE_IDENTIFIER && element.size() == 1 ) { if ( operators.empty() ) { - operators.push( + operators.emplace( this->addNode<OperatorNode>(elementToken) ); } else { - OperatorNode*const lastNode( - static_cast<OperatorNode*>(topNode(operators)) - ); - - if ( precedence(elementToken) > precedence(lastNode->token()) ) { - operators.push( - this->addNode<OperatorNode>(elementToken) - ); + if ( boost::optional<Node*> lastNode{ top(operators) } ) { + OperatorNode*const lastOperator{ + static_cast<OperatorNode*const>(*lastNode) + }; + + if ( precedence(elementToken) + > precedence(lastOperator->token()) ) { + operators.emplace( + this->addNode<OperatorNode>(elementToken) + ); + } else { + boost::optional<Node*> currentOperator{ pop(operators) }; + boost::optional<Node*> rightChild { pop(operands) }; + boost::optional<Node*> leftChild { pop(operands) }; + + if ( currentOperator && + rightChild && + leftChild ) { + static_cast<OperatorNode*const>( + *currentOperator + )->setChildren( + *rightChild, + *leftChild + ); + + operands.emplace(*currentOperator); + + --elementIterator; + } else { + throw operator_exception(); + } + } } else { - OperatorNode*const currOperator( - static_cast<OperatorNode*const>( - popNode(operators) - ) - ); - - currOperator->setChildren( - popNode(operands), - popNode(operands) - ); - - operands.push(currOperator); - - --elementIterator; + throw operator_exception(); } } } else { @@ -157,7 +175,7 @@ Node* Tree::buildTree(const std::string& term) { switch ( determineToken(subElements.front()) ) { case TokenType::VALUE_NUMBER: case TokenType::OPERATOR_MINUS: { - operands.push( + operands.emplace( this->addNode<OperandNode>( stringToDouble(subElements.front()) ) @@ -166,7 +184,7 @@ Node* Tree::buildTree(const std::string& term) { break; } case TokenType::VALUE_IDENTIFIER: { - operands.push( + operands.emplace( this->addNode<ConstantNode>( subElements.front(), this->constants_ @@ -180,7 +198,7 @@ Node* Tree::buildTree(const std::string& term) { } } } else { - operands.push( + operands.emplace( buildTree(element) ); } @@ -188,21 +206,31 @@ Node* Tree::buildTree(const std::string& term) { } while ( !operators.empty() ) { - OperatorNode*const currOperator( - static_cast<OperatorNode*const>( - popNode(operators) - ) - ); + boost::optional<Node*> currentOperator{ pop(operators) }; + boost::optional<Node*> rightChild { pop(operands) }; + boost::optional<Node*> leftChild { pop(operands) }; - currOperator->setChildren( - popNode(operands), - popNode(operands) - ); + if ( currentOperator && + rightChild && + leftChild ) { + static_cast<OperatorNode*const>( + *currentOperator + )->setChildren( + *rightChild, + *leftChild + ); - operands.push(currOperator); + operands.emplace(*currentOperator); + } else { + throw operator_exception(); + } } - return popNode(operands); + if ( boost::optional<Node*> rootNode{ pop(operands) } ) { + return *rootNode; + } else { + throw operator_exception(); + } } } diff --git a/src/utils.cc b/src/utils.cc index 256cad8..46617d8 100644 --- a/src/utils.cc +++ b/src/utils.cc @@ -66,13 +66,13 @@ PrecedenceLevel precedence(const TokenType token) { } std::vector<std::string> lexer(const std::string& term) { - std::vector<std::string> resultBuffer; + std::vector<std::string> resultBuffer{}; - std::string levelBuffer; - std::string numberBuffer; - std::string identifierBuffer; + std::string levelBuffer{}; + std::string numberBuffer{}; + std::string identifierBuffer{}; - TokenType previousToken; + TokenType previousToken{}; uint32_t level{0}; for ( auto&& termIter = term.begin(); |