p4lang · fruffy · Sep 30, 2024
diff --git a/lib/stringify.cpp b/lib/stringify.cpp
@@ -20,6 +20,7 @@ limitations under the License.
 #include <sstream>
 #include <string>
 
+#include "absl/strings/ascii.h"
 #include "big_int.h"
 #include "cstring.h"
 #include "exceptions.h"
@@ -128,4 +129,12 @@ cstring toString(cstring value) {
 
 cstring toString(std::string_view value) { return cstring(value); }
 
+void lowerInPlace(std::string &s) { absl::AsciiStrToLower(&s); }
+
+std::string toLower(std::string_view s) { return absl::AsciiStrToLower(s); }
+
+void upperInPlace(std::string &s) { absl::AsciiStrToUpper(&s); }
+
+std::string toUpper(std::string_view s) { return absl::AsciiStrToUpper(s); }
+
 }  // namespace P4::Util
diff --git a/lib/stringify.h b/lib/stringify.h
@@ -123,6 +123,21 @@ cstring toString(const void *value);
 
 char DigitToChar(int digit);
 
+/// Convert a string to lower case. Using non-ASCII strings might lead to unexpected results..
+/// Performs the lowering operation in place.
+void lowerInPlace(std::string &s);
+
+/// Convert a string to lower case. Using non-ASCII strings might lead to unexpected results..
+/// Returns a copy of the string.
+std::string toLower(std::string_view s);
+
+/// Convert a string to upper case. Using non-ASCII strings might lead to unexpected results..
+/// Performs the up operation in place.
+void upperInPlace(std::string &s);
+
+/// Convert a string to upper case. Using non-ASCII strings might lead to unexpected results..
+std::string toUpper(std::string_view s);
+
 }  // namespace Util
 }  // namespace P4
 

diff --git a/test/CMakeLists.txt b/test/CMakeLists.txt
@@ -53,6 +53,7 @@ set (GTEST_UNITTEST_SOURCES
   gtest/source_file_test.cpp
   gtest/strength_reduction.cpp
   gtest/string_map.cpp
+  gtest/string_test.cpp
   gtest/transforms.cpp
   gtest/rtti_test.cpp
   gtest/nethash.cpp

diff --git a/test/gtest/string_test.cpp b/test/gtest/string_test.cpp
@@ -0,0 +1,165 @@
+#include <gtest/gtest.h>
+
+#include <string>
+
+#include "lib/stringify.h"
+
+namespace P4::Test {
+
+TEST(StringCaseConversionTests, MixedCase) {
+    std::string input = "HeLLo WoRLd!";
+
+    std::string lowerInput = input;
+    Util::lowerInPlace(lowerInput);
+    EXPECT_EQ(lowerInput, "hello world!");
+
+    EXPECT_EQ(Util::toLower(input), "hello world!");
+
+    std::string upperInput = input;
+    Util::upperInPlace(upperInput);
+    EXPECT_EQ(upperInput, "HELLO WORLD!");
+
+    EXPECT_EQ(Util::toUpper(input), "HELLO WORLD!");
+}
+
+TEST(StringCaseConversionTests, DigitsAndSpecialChars) {
+    std::string input = "123ABC$%^";
+
+    std::string lowerInput = input;
+    Util::lowerInPlace(lowerInput);
+    EXPECT_EQ(lowerInput, "123abc$%^");
+
+    EXPECT_EQ(Util::toLower(input), "123abc$%^");
+
+    std::string upperInput = input;
+    Util::upperInPlace(upperInput);
+    EXPECT_EQ(upperInput, "123ABC$%^");
+
+    EXPECT_EQ(Util::toUpper(input), "123ABC$%^");
+}
+
+TEST(StringCaseConversionTests, AlreadyLowercase) {
+    std::string input = "already lowercase";
+
+    std::string lowerInput = input;
+    Util::lowerInPlace(lowerInput);
+    EXPECT_EQ(lowerInput, "already lowercase");
+
+    EXPECT_EQ(Util::toLower(input), "already lowercase");
+
+    Util::upperInPlace(input);
+    EXPECT_EQ(input, "ALREADY LOWERCASE");
+
+    EXPECT_EQ(Util::toUpper("already lowercase"), "ALREADY LOWERCASE");
+}
+
+TEST(StringCaseConversionTests, AlreadyUppercase) {
+    std::string input = "ALREADY UPPERCASE";
+
+    std::string lowerInput = input;
+    Util::lowerInPlace(lowerInput);
+    EXPECT_EQ(lowerInput, "already uppercase");
+
+    EXPECT_EQ(Util::toLower(input), "already uppercase");
+
+    Util::upperInPlace(input);
+    EXPECT_EQ(input, "ALREADY UPPERCASE");
+
+    EXPECT_EQ(Util::toUpper(input), "ALREADY UPPERCASE");
+}
+
+TEST(StringCaseConversionTests, EmptyString) {
+    std::string input;
+
+    Util::lowerInPlace(input);
+    EXPECT_EQ(input, "");
+
+    EXPECT_EQ(Util::toLower(""), "");
+
+    Util::upperInPlace(input);
+    EXPECT_EQ(input, "");
+
+    EXPECT_EQ(Util::toUpper(""), "");
+}
+
+TEST(StringCaseConversionTests, SingleCharacter) {
+    std::string input = "A";
+
+    std::string lowerInput = input;
+    Util::lowerInPlace(lowerInput);
+    EXPECT_EQ(lowerInput, "a");
+
+    EXPECT_EQ(Util::toLower(input), "a");
+
+    std::string upperInput = "b";
+    Util::upperInPlace(upperInput);
+    EXPECT_EQ(upperInput, "B");
+
+    EXPECT_EQ(Util::toUpper("b"), "B");
+}
+
+TEST(StringCaseConversionTests, WhitespaceString) {
+    std::string input = "   HeLlO wOrLd   ";
+
+    std::string lowerInput = input;
+    Util::lowerInPlace(lowerInput);
+    EXPECT_EQ(lowerInput, "   hello world   ");
+
+    EXPECT_EQ(Util::toLower(input), "   hello world   ");
+
+    std::string upperInput = input;
+    Util::upperInPlace(upperInput);
+    EXPECT_EQ(upperInput, "   HELLO WORLD   ");
+
+    EXPECT_EQ(Util::toUpper(input), "   HELLO WORLD   ");
+}
+
+TEST(StringCaseConversionTests, UnicodeCharacters) {
+    std::string input = "áÉíÓú";
+
+    std::string lowerInput = input;
+    Util::lowerInPlace(lowerInput);
+    EXPECT_EQ(lowerInput, "áéíóú");
+
+    EXPECT_EQ(Util::toLower(input), "áéíóú");
+
+    std::string upperInput = input;
+    Util::upperInPlace(upperInput);
+    EXPECT_EQ(upperInput, "ÁÉÍÓÚ");
+
+    EXPECT_EQ(Util::toUpper(input), "ÁÉÍÓÚ");
+}
+
+TEST(StringCaseConversionTests, SymbolsOnly) {
+    std::string input = "@#$%^&*";
+
+    std::string lowerInput = input;
+    Util::lowerInPlace(lowerInput);
+    EXPECT_EQ(lowerInput, "@#$%^&*");
+
+    EXPECT_EQ(Util::toLower(input), "@#$%^&*");
+
+    std::string upperInput = input;
+    Util::upperInPlace(upperInput);
+    EXPECT_EQ(upperInput, "@#$%^&*");
+
+    EXPECT_EQ(Util::toUpper(input), "@#$%^&*");
+}
+
+TEST(StringCaseConversionTests, LongString) {
+    std::string input = "ThisIsAVeryLongStringToTestTheEfficiencyOfTheFunctions";
+
+    std::string lowerInput = input;
+    Util::lowerInPlace(lowerInput);
+    EXPECT_EQ(lowerInput, "thisisaverylongstringtotesttheefficiencyofthefunctions");
+
+    EXPECT_EQ(Util::toLower(input), "thisisaverylongstringtotesttheefficiencyofthefunctions");
+
+    std::string upperInput = input;
+    Util::upperInPlace(upperInput);
+    EXPECT_EQ(upperInput, "THISISAVERYLONGSTRINGTOTESTTHEEFFICIENCYOFTHEFUNCTIONS");
+
+    EXPECT_EQ(Util::toUpper(input), "THISISAVERYLONGSTRINGTOTESTTHEEFFICIENCYOFTHEFUNCTIONS");
+}
+
+}  // namespace P4::Test