intermediate changes

ref:cde9a383711a11544ce7e107a78147fb96cc4029

1 files changed, 81 insertions, 0 deletions

diff --git a/library/cpp/regex/pire/extraencodings.cpp b/library/cpp/regex/pire/extraencodings.cpp
new file mode 100644
index 0000000000..2e507e4b67
--- /dev/null
+++ b/library/cpp/regex/pire/extraencodings.cpp
@@ -0,0 +1,81 @@
+#include <util/system/defaults.h>
+#include <util/system/yassert.h>
+#include <library/cpp/charset/codepage.h>
+#include <util/generic/singleton.h>
+#include <util/generic/yexception.h>
+#include <library/cpp/charset/doccodes.h>
+
+#include "pire.h"
+
+namespace NPire {
+    namespace {
+        // A one-byte encoding which is capable of transforming upper half of the character
+        // table to/from Unicode chars.
+        class TOneByte: public TEncoding {
+        public:
+            TOneByte(ECharset doccode) {
+                Table_ = CodePageByCharset(doccode)->unicode;
+                for (size_t i = 0; i < 256; ++i)
+                    Reverse_.insert(std::make_pair(Table_[i], static_cast<char>(i)));
+            }
+
+            wchar32 FromLocal(const char*& begin, const char* end) const override {
+                if (begin != end)
+                    return Table_[static_cast<unsigned char>(*begin++)];
+                else
+                    ythrow yexception() << "EOF reached in Pire::OneByte::fromLocal()";
+            }
+
+            TString ToLocal(wchar32 c) const override {
+                THashMap<wchar32, char>::const_iterator i = Reverse_.find(c);
+                if (i != Reverse_.end())
+                    return TString(1, i->second);
+                else
+                    return TString();
+            }
+
+            void AppendDot(TFsm& fsm) const override {
+                fsm.AppendDot();
+            }
+
+        private:
+            const wchar32* Table_;
+            THashMap<wchar32, char> Reverse_;
+        };
+
+        template <unsigned N>
+        struct TOneByteHelper: public TOneByte {
+            inline TOneByteHelper()
+                : TOneByte((ECharset)N)
+            {
+            }
+        };
+    }
+
+    namespace NEncodings {
+        const NPire::TEncoding& Koi8r() {
+            return *Singleton<TOneByteHelper<CODES_KOI8>>();
+        }
+
+        const NPire::TEncoding& Cp1251() {
+            return *Singleton<TOneByteHelper<CODES_WIN>>();
+        }
+
+        const NPire::TEncoding& Get(ECharset encoding) {
+            switch (encoding) {
+                case CODES_WIN:
+                    return Cp1251();
+                case CODES_KOI8:
+                    return Koi8r();
+                case CODES_ASCII:
+                    return NPire::NEncodings::Latin1();
+                case CODES_UTF8:
+                    return NPire::NEncodings::Utf8();
+                default:
+                    ythrow yexception() << "Pire::Encodings::get(ECharset): unknown encoding " << (int)encoding;
+            }
+        }
+
+    }
+
+}