From 754cc721222ccb01acc4d93ffd8f88f172a0cdd0 Mon Sep 17 00:00:00 2001
From: Adrian Kummerländer
Date: Sat, 19 Oct 2013 19:35:16 +0200
Subject: POC: alphabetic constants * New priority for alphabetic characters *
 Overloaded OperandNode constructor * Currently not usable, only basic proof
 of concept

---
 src/nodes.cc |  3 +++
 src/nodes.h  |  1 +
 src/tree.cc  | 32 ++++++++++++++++++++------
 src/tree.h   |  1 +
 src/utils.cc | 75 +++++++++++++++++++++++++++++++++++++-----------------------
 5 files changed, 76 insertions(+), 36 deletions(-)

diff --git a/src/nodes.cc b/src/nodes.cc
index 390eac7..fac74a0 100644
--- a/src/nodes.cc
+++ b/src/nodes.cc
@@ -10,6 +10,9 @@ namespace SimpleParser {
 OperandNode::OperandNode(double val):
 	value_(val) { }
 
+OperandNode::OperandNode(std::string identifier):
+	value_(42) { }
+
 double OperandNode::solve() {
 	return this->value_;
 }
diff --git a/src/nodes.h b/src/nodes.h
index 3a99474..a59f4a5 100644
--- a/src/nodes.h
+++ b/src/nodes.h
@@ -39,6 +39,7 @@ class OperatorNode: public Node {
 class OperandNode: public Node {
 	public:
 		explicit OperandNode(double);
+		explicit OperandNode(std::string);
 
 		virtual double solve();
 		virtual NodeType getType();
diff --git a/src/tree.cc b/src/tree.cc
index 1dcfca6..81de460 100644
--- a/src/tree.cc
+++ b/src/tree.cc
@@ -84,6 +84,18 @@ Node* Tree::addOperand(Node** place, double value) {
 	return this->node_collection_.back().get();
 }
 
+Node* Tree::addOperand(Node** place, std::string value) {
+	this->node_collection_.emplace_back(
+		new OperandNode(value)
+	);
+
+	if ( place != nullptr ) {
+		*place = this->node_collection_.back().get();
+	}
+
+	return this->node_collection_.back().get();
+}
+
 Node* Tree::addOperator(Node** place, char oper) {
 	this->node_collection_.emplace_back(
 		new OperatorNode(oper)
@@ -119,7 +131,7 @@ Node* Tree::buildTree(std::string term) {
 		std::string& currTerm = (*termIter);
 		priority              = getPriority(currTerm[0]);
 
-		if ( priority != -1 && (*termIter).size() == 1 ) {
+		if ( priority != -1 && priority != 100 && (*termIter).size() == 1 ) {
 			if ( !operatorStack.empty() ) {
 				OperatorNode* lastNode(
 					static_cast<OperatorNode*>(topNodeFrom(operatorStack))
@@ -152,13 +164,19 @@ Node* Tree::buildTree(std::string term) {
 			tmpLexer = lexer(*termIter);
 
 			if ( tmpLexer.size() == 1 ) {
-				double value;
-				std::istringstream convertStream(tmpLexer[0]);
-				convertStream >> value;
+				if ( getPriority(tmpLexer[0][0]) == -1 ) {
+					double value;
+					std::istringstream convertStream(tmpLexer[0]);
+					convertStream >> value;
 
-				operandStack.push(
-					this->addOperand(nullptr,value)
-				);
+					operandStack.push(
+						this->addOperand(nullptr,value)
+					);
+				} else if ( getPriority(tmpLexer[0][0]) == 100 ) {
+					operandStack.push(
+						this->addOperand(nullptr,tmpLexer[0])
+					);
+				}
 			} else if ( tmpLexer.size() > 1 ) {
 				operandStack.push(
 					buildTree(*termIter)
diff --git a/src/tree.h b/src/tree.h
index 5beec87..f20f765 100644
--- a/src/tree.h
+++ b/src/tree.h
@@ -18,6 +18,7 @@ class Tree {
 
 	private:
 		Node* addOperand(Node**, double);
+		Node* addOperand(Node**, std::string);
 		Node* addOperator(Node**, char);
 		Node* buildTree(std::string);
 
diff --git a/src/utils.cc b/src/utils.cc
index 7457ae2..8914166 100644
--- a/src/utils.cc
+++ b/src/utils.cc
@@ -1,36 +1,42 @@
 #include "utils.h"
+#include "tree.h"
 #include "exceptions.h"
 
-#include "tree.h"
+#include <cctype>
 
 namespace SimpleParser {
 
 int8_t getPriority(char tmp) {
-	switch ( tmp ) {
-		case '-':
-			return 10;
-		case '+':
-			return 10;
-		case '/':
-			return 20;
-		case '*':
-			return 20;
-		case '^':
-			return 30;
-		case '(':
-			return 90;
-		case ')':
-			return 90;
-		case ',':
-			return -1;
-		default:
-			return -1;
+	if ( std::isalpha(tmp) ) {
+		return 100;
+	} else {
+		switch ( tmp ) {
+			case '-':
+				return 10;
+			case '+':
+				return 10;
+			case '/':
+				return 20;
+			case '*':
+				return 20;
+			case '^':
+				return 30;
+			case '(':
+				return 90;
+			case ')':
+				return 90;
+			case ',':
+				return -1;
+			default:
+				return -1;
+		}
 	}
 }
 
 std::vector<std::string> lexer(std::string term) {
 	std::string tmp;
-	std::string tmpNum;
+	std::string tmpNumber;
+	std::string tmpIdentifier;
 	std::vector<std::string> output;
 
 	int8_t   priority     = 0;
@@ -42,17 +48,26 @@ std::vector<std::string> lexer(std::string term) {
 	      termIter++ ) {
 		priority = getPriority(*termIter);
 
-		if ( priority == -1 || ( termIter == term.begin() &&
-		                         priority == 10 ) ) {
+		if ( priority == -1 || priority == 100 || ( termIter == term.begin() &&
+		                                            priority == 10 ) ) {
 			if ( level > 0 ) {
 				tmp += *termIter;
 			} else {
-				tmpNum += *termIter;
+				if ( priority == -1 ) {
+					tmpNumber += *termIter;
+				} else if ( priority == 100 ) {
+					tmpIdentifier += *termIter;
+				}
 			}
 		} else {
-			if ( lastPriority == -1 && level == 0 ) {
-				output.push_back(tmpNum);
-				tmpNum.clear();
+			if ( level == 0 ) {
+				if ( lastPriority == -1 ) {
+					output.push_back(tmpNumber);
+					tmpNumber.clear();
+				} else if ( lastPriority == 100 ) {
+					output.push_back(tmpIdentifier);
+					tmpIdentifier.clear();
+				}
 			}
 
 			switch ( *termIter ) {
@@ -96,12 +111,14 @@ std::vector<std::string> lexer(std::string term) {
 	}
 
 	if ( lastPriority == -1 ) {
-		output.push_back(tmpNum);
+		output.push_back(tmpNumber);
+	} else if ( lastPriority == 100 ) {
+		output.push_back(tmpIdentifier);
 	} else if ( lastPriority != 90 ) {
 		throw operator_exception();
 	}
 
-	if (level != 0) {
+	if ( level != 0 ) {
 		throw parenthese_exception();
 	}
 
-- 
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