add antlr source code and ReadMe

[toc] / antlr4-cpp-runtime-4.9.2-source / runtime / src / support / StringUtils.h

diff --git a/antlr4-cpp-runtime-4.9.2-source/runtime/src/support/StringUtils.h b/antlr4-cpp-runtime-4.9.2-source/runtime/src/support/StringUtils.h
new file mode 100644 (file)
index 0000000..d00cc52
--- /dev/null
+++ b/antlr4-cpp-runtime-4.9.2-source/runtime/src/support/StringUtils.h
@@ -0,0 +1,76 @@
+/* Copyright (c) 2012-2017 The ANTLR Project. All rights reserved.
+ * Use of this file is governed by the BSD 3-clause license that
+ * can be found in the LICENSE.txt file in the project root.
+ */
+
+#pragma once
+
+#include "antlr4-common.h"
+
+#ifdef USE_UTF8_INSTEAD_OF_CODECVT
+#include "utf8.h"
+#endif
+
+namespace antlrcpp {
+
+  // For all conversions utf8 <-> utf32.
+  // I wouldn't prefer wstring_convert because: according to
+  // https://en.cppreference.com/w/cpp/locale/wstring_convert,
+  // wstring_convert is deprecated in C++17.
+  // utfcpp (https://github.com/nemtrif/utfcpp) is a substitution.
+#ifndef USE_UTF8_INSTEAD_OF_CODECVT
+  // VS 2015 and VS 2017 have different bugs in std::codecvt_utf8<char32_t> (VS 2013 works fine).
+  #if defined(_MSC_VER) && _MSC_VER >= 1900 && _MSC_VER < 2000
+    typedef std::wstring_convert<std::codecvt_utf8<__int32>, __int32> UTF32Converter;
+  #else
+    typedef std::wstring_convert<std::codecvt_utf8<char32_t>, char32_t> UTF32Converter;
+  #endif
+#endif
+
+  // The conversion functions fails in VS2017, so we explicitly use a workaround.
+  template<typename T>
+  inline std::string utf32_to_utf8(T const& data)
+  {
+    #ifndef USE_UTF8_INSTEAD_OF_CODECVT
+      // Don't make the converter static or we have to serialize access to it.
+      thread_local UTF32Converter converter;
+
+      #if defined(_MSC_VER) && _MSC_VER >= 1900 && _MSC_VER < 2000
+        const auto p = reinterpret_cast<const int32_t *>(data.data());
+        return converter.to_bytes(p, p + data.size());
+      #else
+        return converter.to_bytes(data);
+      #endif
+    #else
+      std::string narrow;
+      utf8::utf32to8(data.begin(), data.end(), std::back_inserter(narrow));
+      return narrow;
+    #endif
+  }
+
+  inline UTF32String utf8_to_utf32(const char* first, const char* last)
+  {
+    #ifndef USE_UTF8_INSTEAD_OF_CODECVT
+      thread_local UTF32Converter converter;
+
+      #if defined(_MSC_VER) && _MSC_VER >= 1900 && _MSC_VER < 2000
+        auto r = converter.from_bytes(first, last);
+        i32string s = reinterpret_cast<const int32_t *>(r.data());
+        return s;
+      #else
+        std::u32string s = converter.from_bytes(first, last);
+        return s;
+      #endif
+    #else
+      UTF32String wide;
+      utf8::utf8to32(first, last, std::back_inserter(wide));
+      return wide;
+    #endif
+  }
+
+  void replaceAll(std::string &str, std::string const& from, std::string const& to);
+
+  // string <-> wstring conversion (UTF-16), e.g. for use with Window's wide APIs.
+  ANTLR4CPP_PUBLIC std::string ws2s(std::wstring const& wstr);
+  ANTLR4CPP_PUBLIC std::wstring s2ws(std::string const& str);
+}