Add a UTF-16 codec

[libs/core.git] / source / stringcodec / utf16.h

diff --git a/source/stringcodec/utf16.h b/source/stringcodec/utf16.h
new file mode 100644 (file)
index 0000000..729ab2e
--- /dev/null
+++ b/source/stringcodec/utf16.h
@@ -0,0 +1,99 @@
+#ifndef MSP_STRINGCODEC_UTF16_H_
+#define MSP_STRINGCODEC_UTF16_H_
+
+#include "codec.h"
+
+namespace Msp {
+namespace StringCodec {
+
+/**
+The UTF-16 codec, as specified in the Unicode standard.  Both little and big
+endian are supported, as well as autodetection with the BOM.  In the absence
+of a BOM, big endian is assumed.
+*/
+class Utf16: public StandardCodec<Utf16>
+{
+public:
+       enum Endian
+       {
+               AUTO,
+               BIG,
+               LITTLE
+       };
+
+       class Encoder: public Codec::Encoder
+       {
+       private:
+               Endian endian;
+               bool emit_bom;
+
+       public:
+               Encoder(ErrorMode em = DEFAULT, Endian en = BIG);
+
+               virtual void encode_char(unichar, std::string &);
+       private:
+               virtual void transliterate(unichar, std::string &);
+       };
+
+       class Decoder: public Codec::Decoder
+       {
+       private:
+               Endian endian;
+
+       public:
+               Decoder(ErrorMode em = DEFAULT, Endian en = AUTO);
+
+               virtual unichar decode_char(const std::string &, std::string::const_iterator &);
+       private:
+               unichar decode_unit(const std::string &, const std::string::const_iterator &, std::string::const_iterator &);
+       };
+
+private:
+       Endian endian;
+
+public:
+       Utf16(ErrorMode em = DEFAULT, Endian en = AUTO):
+               StandardCodec<Utf16>(em),
+               endian(en)
+       { }
+
+       virtual const char *get_name() const
+       { return endian==BIG ? "UTF-16-BE" : "UTF-16-LE"; }
+
+       virtual Encoder *create_encoder(ErrorMode em = DEFAULT) const
+       { return new Encoder(get_error_mode(em), endian); }
+
+       virtual Decoder *create_decoder(ErrorMode em = DEFAULT) const
+       { return new Decoder(get_error_mode(em), endian); }
+};
+
+
+/**
+A helper template to define the Utf16Be and Utf16Le types.
+*/
+template<Utf16::Endian en>
+class Utf16E: public Utf16
+{
+public:
+       class Encoder: public Utf16::Encoder
+       {
+       public:
+               Encoder(ErrorMode em = DEFAULT): Utf16::Encoder(em, en) { }
+       };
+
+       class Decoder: public Utf16::Decoder
+       {
+       public:
+               Decoder(ErrorMode em = DEFAULT): Utf16::Decoder(em, en) { }
+       };
+
+       Utf16E(ErrorMode em = DEFAULT): Utf16(em, en) { }
+};
+
+typedef Utf16E<Utf16::BIG> Utf16Be;
+typedef Utf16E<Utf16::LITTLE> Utf16Le;
+
+} // namespace StringCodec
+} // namespace Msp
+
+#endif