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54 lines
2.7 KiB
C++
54 lines
2.7 KiB
C++
/* This file is (c) 2008-2012 Konstantin Isakov <ikm@goldendict.org>
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* Part of GoldenDict. Licensed under GPLv3 or later, see the LICENSE file */
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#ifndef __WSTRING_HH_INCLUDED__
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#define __WSTRING_HH_INCLUDED__
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#include <string>
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/// While most systems feature a 4-byte wchar_t and an UCS-4 Unicode
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/// characters representation for it, Windows uses 2-byte wchar_t and an UTF-16
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/// encoding. The use of UTF-16 on Windows is most probably a homeage to an
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/// ancient history dating back to when there was nothing but a BMP, and
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/// all Unicode chars were 2 bytes long. After the Unicode got expanded past
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/// two-byte representation, the guys at Microsoft had probably decided that
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/// the least painful way to go is to just switch to UTF-16. Or so's the theory.
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///
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/// Now, the UTF family is an encoding, made for transit purposes -- is not a
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/// representation. While it's good for passthrough, it's not directly
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/// applicable for manipulation on Unicode symbols. It must be decoded first to
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/// a normal UCS. Think like this: UTF to UCS is something like Base64 to ASCII.
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///
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/// The distinction between Microsoft platform and all other ones is that while
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/// the latters are stuck in an 8-bit era and use UTF-8 to pass unicode around
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/// through its venerable interfaces, the former one is stuck in a 16-bit era,
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/// and uses UTF-16 instead. Neither solution allows for direct processing of
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/// the symbols in those strings without decoding them first. And the 16-bit
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/// solution is even more ugly than the 8-bit one, because it doesn't have a
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/// benefit of ASCII compatibility, having a much more useless UCS-2
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/// compatibility instead. It's stuck in the middle of nowhere, really.
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///
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/// The question is, what are we going to do with all this? When we do Unicode
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/// processing in GoldenDict, we want to use real Unicode characters, not some
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/// UTF-16 encoded ones. To that end, we have two options under Windows: first,
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/// use QString, and second, use basic_string< unsigned int >.
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/// While we use QStrings for the GUI and other non-critical code, there is a
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/// serious doubt on the efficiency of QStrings for bulk text processing. And
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/// since a lot of code uses wstring already, it would be much easier to convert
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/// it to use basic_string< unsigned int > instead, since it shares the same
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/// template, and therefore the interface too, with wstring. That's why we
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/// introduce our own gd::wstring and gd::wchar types here. On all systems but
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/// Windows, they are equivalent to std::wstring and wchar_t. On Windows, they
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/// are basic_string< unsigned int > and unsigned int.
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///
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///
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/// Now we have a better built-in type as char32_t and std::u32string
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namespace gd
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{
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typedef char32_t wchar;
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typedef std::u32string wstring;
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}
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#endif
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