add eval_unaries function

.gitignore

@@ -240,3 +240,4 @@ ModelManifest.xml
 
 # FAKE - F# Make
 .fake/
+/Parse Infix/thoughts for consideration.txt

Parse Infix/Parse Infix.vcxproj

@@ -147,14 +147,13 @@
   </ItemDefinitionGroup>
   <ItemGroup>
     <ClCompile Include="infix_evaluator.cpp" />
-    <ClCompile Include="infix_to_postfix.cpp" />
-    <ClCompile Include="postfix_evaluator.cpp" />
     <ClCompile Include="Source.cpp" />
   </ItemGroup>
   <ItemGroup>
     <ClInclude Include="infix_evaluator.h" />
-    <ClInclude Include="infix_to_postfix.h" />
-    <ClInclude Include="postfix_evaluator.h" />
+  </ItemGroup>
+  <ItemGroup>
+    <Text Include="thoughts for consideration.txt" />
   </ItemGroup>
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.targets" />
   <ImportGroup Label="ExtensionTargets">

Parse Infix/Parse Infix.vcxproj.filters

@@ -18,25 +18,18 @@
     <ClCompile Include="Source.cpp">
       <Filter>Source Files</Filter>
     </ClCompile>
-    <ClCompile Include="postfix_evaluator.cpp">
-      <Filter>Source Files</Filter>
-    </ClCompile>
-    <ClCompile Include="infix_to_postfix.cpp">
-      <Filter>Source Files</Filter>
-    </ClCompile>
     <ClCompile Include="infix_evaluator.cpp">
       <Filter>Source Files</Filter>
     </ClCompile>
   </ItemGroup>
   <ItemGroup>
-    <ClInclude Include="infix_to_postfix.h">
-      <Filter>Header Files</Filter>
-    </ClInclude>
-    <ClInclude Include="postfix_evaluator.h">
-      <Filter>Header Files</Filter>
-    </ClInclude>
     <ClInclude Include="infix_evaluator.h">
       <Filter>Header Files</Filter>
     </ClInclude>
   </ItemGroup>
+  <ItemGroup>
+    <Text Include="thoughts for consideration.txt">
+      <Filter>Resource Files</Filter>
+    </Text>
+  </ItemGroup>
 </Project>

Parse Infix/Source.cpp

@@ -1,7 +1,11 @@
 #include <cstdlib>
+#include <iostream>
 #include "infix_evaluator.h"
 using namespace std;
 
 void main() {
-
+	infix_evaluator test;
+	string test_string = "+!!----";
+	test.eval_unaries(0, 7, 5, test_string);
+	getchar();
 }

Parse Infix/infix_evaluator.cpp

@@ -1 +1,46 @@
 #include "infix_evaluator.h"
+
+void infix_evaluator::eval_stack(int precedence)
+{
+}
+//infix_string&, int start, length, operand.  Can strip spaces
+int infix_evaluator::eval_unaries(int start, int length, int operand, string& infix_string)
+{	
+	if (length == 0)
+		return operand;
+	else {
+		int index = start + length - 1;
+		char token = infix_string[index];
+		int count = 1;
+		while (count < length && infix_string[index] == infix_string[index -1]) {
+			count++;
+			index--;
+		}
+		if (token == '!') {
+			if (count % 2 == 0)
+				eval_unaries(start, length - count, !!operand, infix_string);
+			else
+				eval_unaries(start, length - count, !operand, infix_string);
+		}else if (token == '+') {
+			if (count % 2 == 0) {
+				for (int i = 0; i < count / 2; i++) {
+					operand++;
+				}
+				eval_unaries(start, length - count, operand, infix_string);
+			}
+			else {
+				cout << "Binary operator with single operand at index " << index;
+			}
+		}else if (token == '-') {
+			if (count % 2 == 0) {
+				for (int i = 0; i < count / 2; i++) {
+					operand--;
+				}
+				eval_unaries(start, length - count, operand, infix_string);
+			}
+			else {
+				cout << "Binary operator with single operand at index " << index;
+			}
+		}
+	}
+}

Parse Infix/infix_evaluator.h

@@ -1,27 +1,29 @@
 #pragma once
 
-#include "infix_to_postfix.h"
 #include<string>
 #include<stack>
+#include<iostream>
 using namespace std;
 
-class infix_to_postfix {
+class infix_evaluator {
 public:
 	// @param infix_string is the infix expression to evaluate.
 	// @return is the value of the string as a single integer
 	int eval(string infix_string);
-private:
+//private:
 	stack<int>operators;
 	stack<char>operands;
 
-	// evaluates the stacks as far as possible and pushes the result to operators stack.
-	// @param precedence is the precedence of the next operator to be added to the stack.
+	// evaluates the stacks as far as possible and pushes the result to operand stack.
+	// @param precedence is the precedence of the next operator to be added to the operator stack.
 	void eval_stack(int precedence);
 
-	// evaluates one or many repeated +, -, or ! in a substring of infix_string
-	// @param start is the first index of the substring
+	// evaluates one or many repeated +, -, or ! in a substring of infix_string.  Whitespace between
+	// consecutive operators is ignored.
+	// @param start is an interator to the first index of the substring in the infix_string
 	// @param length is the length of the substring
 	// @param operand is the operand which the unary operators will be applied to
+	// @param operator_string is the string of one or many repeated + and/or -  and/or !
 	// @return is the value of operand after unary operations have been applied.
-	int eval_unaries(int start, int length, int operand);
+	int eval_unaries(int start, int length, int operand, string& infix_string);
 };