Added method Lower()

StringTools/StringTools/StringTools.cpp

@@ -59,4 +59,40 @@ std::string StringTools::Replace(const std::string& str, const std::string& find
     ss << subst;
 
     return Replace(str, find, ss.str());
-}
+}
+
+std::string StringTools::Lower(const std::string& str)
+{
+    std::stringstream ss;
+
+    for (std::size_t i = 0; i < str.size(); i++)
+    {
+        const char c = str[i];
+
+        // Quick-accept: regular letters
+        if ((c >= 'A') && (c <= 'Z'))
+            ss << (char)(c + 32);
+
+        // Damned umlautes:
+        else if (c == '<EFBFBD>') ss << '<EFBFBD>';
+        else if (c == '<EFBFBD>') ss << '<EFBFBD>';
+        else if (c == '<EFBFBD>') ss << '<EFBFBD>';
+        else if (c == '<EFBFBD>') ss << '<EFBFBD>';
+        else if (c == '<EFBFBD>') ss << '<EFBFBD>';
+        else if (c == '<EFBFBD>') ss << '<EFBFBD>';
+        else if (c == '<EFBFBD>') ss << '<EFBFBD>';
+        else if (c == '<EFBFBD>') ss << '<EFBFBD>';
+        else if (c == '<EFBFBD>') ss << '<EFBFBD>';
+        else if (c == '<EFBFBD>') ss << '<EFBFBD>';
+        else if (c == '<EFBFBD>') ss << '<EFBFBD>';
+        else if (c == '<EFBFBD>') ss << '<EFBFBD>';
+        else if (c == '<EFBFBD>') ss << '<EFBFBD>';
+        else if (c == '<EFBFBD>') ss << '<EFBFBD>';
+        else if (c == '<EFBFBD>') ss << '<EFBFBD>';
+
+        // Else: keep the character as is
+        else ss << c;
+    }
+
+    return ss.str();
+}

StringTools/StringTools/StringTools.h

@@ -17,6 +17,9 @@ public:
 	//! Will replace every occurence of `find` in `str` by `subst`.
 	static std::string Replace(const std::string& str, const std::string& find, const char subst);
 
+	//! Will make a string all-lowercase. Only works with latin and german umlautes, plus some extras.
+	static std::string Lower(const std::string& str);
+
 private:
 	// No instanciation! >:(
 	StringTools();

StringTools/Test/Lower.cpp

@@ -0,0 +1,200 @@
+#include "CppUnitTest.h"
+#include "../StringTools/StringTools.h"
+
+using namespace Microsoft::VisualStudio::CppUnitTestFramework;
+
+namespace _StringTools
+{
+	TEST_CLASS(_Lower)
+	{
+	public:
+
+		// Tests that lowering an empty string returns an empty string
+		TEST_METHOD(EmptyString)
+		{
+			// Setup
+			const std::string in = "";
+
+			// Exercise
+			const std::string out = StringTools::Lower(in);
+
+			// Verify
+			Assert::AreEqual("", out.c_str());
+			return;
+		}
+
+		// Tests that lowering a string without any letters returns an itself
+		TEST_METHOD(Symbols)
+		{
+			// Setup
+			const std::string in = "66! _-\n*";
+
+			// Exercise
+			const std::string out = StringTools::Lower(in);
+
+			// Verify
+			Assert::AreEqual("66! _-\n*", out.c_str());
+			return;
+		}
+
+		// Tests that lowering a string of lowercase letters returns itself
+		TEST_METHOD(AlreadyLowered)
+		{
+			// Setup
+			const std::string in = "ughareyouserious";
+
+			// Exercise
+			const std::string out = StringTools::Lower(in);
+
+			// Verify
+			Assert::AreEqual("ughareyouserious", out.c_str());
+			return;
+		}
+
+		// Tests that lowering a string of uppercase letters returns the lowercase version
+		TEST_METHOD(Uppercase)
+		{
+			// Setup
+			const std::string in = "UGHAREYOUSERIOUS";
+
+			// Exercise
+			const std::string out = StringTools::Lower(in);
+
+			// Verify
+			Assert::AreEqual("ughareyouserious", out.c_str());
+			return;
+		}
+
+		// Tests that lowering a string of uppercase, lowercase letters and symbols returns the lowercase version
+		TEST_METHOD(Mixed)
+		{
+			// Setup
+			const std::string in = "Ugh, Are You Serious?! DON'T DO THAT!!!";
+
+			// Exercise
+			const std::string out = StringTools::Lower(in);
+
+			// Verify
+			Assert::AreEqual("ugh, are you serious?! don't do that!!!", out.c_str());
+			return;
+		}
+
+		// Tests that lowering already lowered umlautes returns itself
+		TEST_METHOD(Umlautes_already_lower_a)
+		{
+			// Setup
+			const std::string in = "<EFBFBD><EFBFBD><EFBFBD><EFBFBD>";
+
+			// Exercise
+			const std::string out = StringTools::Lower(in);
+
+			// Verify
+			Assert::AreEqual("<EFBFBD><EFBFBD><EFBFBD><EFBFBD>", out.c_str());
+		}
+
+		// Tests that lowering uppercase umlautes returns the lowered umlautes
+		TEST_METHOD(Umlautes_upper_a)
+		{
+			// Setup
+			const std::string in = "<EFBFBD><EFBFBD><EFBFBD><EFBFBD>";
+
+			// Exercise
+			const std::string out = StringTools::Lower(in);
+
+			// Verify
+			Assert::AreEqual("<EFBFBD><EFBFBD><EFBFBD><EFBFBD>", out.c_str());
+		}
+
+		// Tests that lowering already lowered umlautes returns itself
+		TEST_METHOD(Umlautes_already_lower_e)
+		{
+			// Setup
+			const std::string in = "<EFBFBD><EFBFBD><EFBFBD>";
+
+			// Exercise
+			const std::string out = StringTools::Lower(in);
+
+			// Verify
+			Assert::AreEqual("<EFBFBD><EFBFBD><EFBFBD>", out.c_str());
+		}
+
+		// Tests that lowering uppercase umlautes returns the lowered umlautes
+		TEST_METHOD(Umlautes_upper_e)
+		{
+			// Setup
+			const std::string in = "<EFBFBD><EFBFBD><EFBFBD>";
+
+			// Exercise
+			const std::string out = StringTools::Lower(in);
+
+			// Verify
+			Assert::AreEqual("<EFBFBD><EFBFBD><EFBFBD>", out.c_str());
+		}
+
+		// Tests that lowering already lowered umlautes returns itself
+		TEST_METHOD(Umlautes_already_lower_u)
+		{
+			// Setup
+			const std::string in = "<EFBFBD><EFBFBD><EFBFBD><EFBFBD>";
+
+			// Exercise
+			const std::string out = StringTools::Lower(in);
+
+			// Verify
+			Assert::AreEqual("<EFBFBD><EFBFBD><EFBFBD><EFBFBD>", out.c_str());
+		}
+
+		// Tests that lowering uppercase umlautes returns the lowered umlautes
+		TEST_METHOD(Umlautes_upper_u)
+		{
+			// Setup
+			const std::string in = "<EFBFBD><EFBFBD><EFBFBD><EFBFBD>";
+
+			// Exercise
+			const std::string out = StringTools::Lower(in);
+
+			// Verify
+			Assert::AreEqual("<EFBFBD><EFBFBD><EFBFBD><EFBFBD>", out.c_str());
+		}
+
+		// Tests that lowering already lowered umlautes returns itself
+		TEST_METHOD(Umlautes_already_lower_o)
+		{
+			// Setup
+			const std::string in = "<EFBFBD><EFBFBD><EFBFBD><EFBFBD>";
+
+			// Exercise
+			const std::string out = StringTools::Lower(in);
+
+			// Verify
+			Assert::AreEqual("<EFBFBD><EFBFBD><EFBFBD><EFBFBD>", out.c_str());
+		}
+
+		// Tests that lowering uppercase umlautes returns the lowered umlautes
+		TEST_METHOD(Umlautes_upper_o)
+		{
+			// Setup
+			const std::string in = "<EFBFBD><EFBFBD><EFBFBD><EFBFBD>";
+
+			// Exercise
+			const std::string out = StringTools::Lower(in);
+
+			// Verify
+			Assert::AreEqual("<EFBFBD><EFBFBD><EFBFBD><EFBFBD>", out.c_str());
+		}
+
+		// Tests that lowering a string of uppercase, lowercase letters and symbols returns the lowercase version, even with umlauts
+		TEST_METHOD(Mixed_with_umlautes)
+		{
+			// Setup
+			const std::string in = "<EFBFBD>gh, <20>r<EFBFBD> Y<><59> Seri<72><69>s?! D<>N'T D<> TH<54>T!!!";
+
+			// Exercise
+			const std::string out = StringTools::Lower(in);
+
+			// Verify
+			Assert::AreEqual("<EFBFBD>gh, <20>r<EFBFBD> y<><79> seri<72><69>s?! d<>n't d<> th<74>t!!!", out.c_str());
+			return;
+		}
+	};
+}

StringTools/Test/Test.vcxproj

@@ -162,6 +162,7 @@
     </ProjectReference>
   </ItemGroup>
   <ItemGroup>
+    <ClCompile Include="Lower.cpp" />
     <ClCompile Include="Replace_Char.cpp" />
     <ClCompile Include="Replace_String.cpp" />
   </ItemGroup>

StringTools/Test/Test.vcxproj.filters

@@ -21,5 +21,8 @@
     <ClCompile Include="Replace_String.cpp">
       <Filter>Quelldateien</Filter>
     </ClCompile>
+    <ClCompile Include="Lower.cpp">
+      <Filter>Quelldateien</Filter>
+    </ClCompile>
   </ItemGroup>
 </Project>