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Diffstat (limited to 'vendor/maunium.net/go/tcell/encoding.go')
| -rw-r--r-- | vendor/maunium.net/go/tcell/encoding.go | 139 |
1 files changed, 0 insertions, 139 deletions
diff --git a/vendor/maunium.net/go/tcell/encoding.go b/vendor/maunium.net/go/tcell/encoding.go deleted file mode 100644 index 596a6e8..0000000 --- a/vendor/maunium.net/go/tcell/encoding.go +++ /dev/null @@ -1,139 +0,0 @@ -// Copyright 2015 The TCell Authors -// -// Licensed under the Apache License, Version 2.0 (the "License"); -// you may not use file except in compliance with the License. -// You may obtain a copy of the license at -// -// http://www.apache.org/licenses/LICENSE-2.0 -// -// Unless required by applicable law or agreed to in writing, software -// distributed under the License is distributed on an "AS IS" BASIS, -// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. -// See the License for the specific language governing permissions and -// limitations under the License. - -package tcell - -import ( - "strings" - "sync" - - "golang.org/x/text/encoding" - - gencoding "github.com/gdamore/encoding" -) - -var encodings map[string]encoding.Encoding -var encodingLk sync.Mutex -var encodingFallback EncodingFallback = EncodingFallbackFail - -// RegisterEncoding may be called by the application to register an encoding. -// The presence of additional encodings will facilitate application usage with -// terminal environments where the I/O subsystem does not support Unicode. -// -// Windows systems use Unicode natively, and do not need any of the encoding -// subsystem when using Windows Console screens. -// -// Please see the Go documentation for golang.org/x/text/encoding -- most of -// the common ones exist already as stock variables. For example, ISO8859-15 -// can be registered using the following code: -// -// import "golang.org/x/text/encoding/charmap" -// -// ... -// RegisterEncoding("ISO8859-15", charmap.ISO8859_15) -// -// Aliases can be registered as well, for example "8859-15" could be an alias -// for "ISO8859-15". -// -// For POSIX systems, the tcell package will check the environment variables -// LC_ALL, LC_CTYPE, and LANG (in that order) to determine the character set. -// These are expected to have the following pattern: -// -// $language[.$codeset[@$variant] -// -// We extract only the $codeset part, which will usually be something like -// UTF-8 or ISO8859-15 or KOI8-R. Note that if the locale is either "POSIX" -// or "C", then we assume US-ASCII (the POSIX 'portable character set' -// and assume all other characters are somehow invalid.) -// -// Modern POSIX systems and terminal emulators may use UTF-8, and for those -// systems, this API is also unnecessary. For example, Darwin (MacOS X) and -// modern Linux running modern xterm generally will out of the box without -// any of this. Use of UTF-8 is recommended when possible, as it saves -// quite a lot processing overhead. -// -// Note that some encodings are quite large (for example GB18030 which is a -// superset of Unicode) and so the application size can be expected ot -// increase quite a bit as each encoding is added. The East Asian encodings -// have been seen to add 100-200K per encoding to the application size. -// -func RegisterEncoding(charset string, enc encoding.Encoding) { - encodingLk.Lock() - charset = strings.ToLower(charset) - encodings[charset] = enc - encodingLk.Unlock() -} - -// EncodingFallback describes how the system behavees when the locale -// requires a character set that we do not support. The system always -// supports UTF-8 and US-ASCII. On Windows consoles, UTF-16LE is also -// supported automatically. Other character sets must be added using the -// RegisterEncoding API. (A large group of nearly all of them can be -// added using the RegisterAll function in the encoding sub package.) -type EncodingFallback int - -const ( - // EncodingFallbackFail behavior causes GetEncoding to fail - // when it cannot find an encoding. - EncodingFallbackFail = iota - - // EncodingFallbackASCII behaviore causes GetEncoding to fall back - // to a 7-bit ASCII encoding, if no other encoding can be found. - EncodingFallbackASCII - - // EncodingFallbackUTF8 behavior causes GetEncoding to assume - // UTF8 can pass unmodified upon failure. Note that this behavior - // is not recommended, unless you are sure your terminal can cope - // with real UTF8 sequences. - EncodingFallbackUTF8 -) - -// SetEncodingFallback changes the behavior of GetEncoding when a suitable -// encoding is not found. The default is EncodingFallbackFail, which -// causes GetEncoding to simply return nil. -func SetEncodingFallback(fb EncodingFallback) { - encodingLk.Lock() - encodingFallback = fb - encodingLk.Unlock() -} - -// GetEncoding is used by Screen implementors who want to locate an encoding -// for the given character set name. Note that this will return nil for -// either the Unicode (UTF-8) or ASCII encodings, since we don't use -// encodings for them but instead have our own native methods. -func GetEncoding(charset string) encoding.Encoding { - charset = strings.ToLower(charset) - encodingLk.Lock() - defer encodingLk.Unlock() - if enc, ok := encodings[charset]; ok { - return enc - } - switch encodingFallback { - case EncodingFallbackASCII: - return gencoding.ASCII - case EncodingFallbackUTF8: - return encoding.Nop - } - return nil -} - -func init() { - // We always support UTF-8 and ASCII. - encodings = make(map[string]encoding.Encoding) - encodings["utf-8"] = gencoding.UTF8 - encodings["utf8"] = gencoding.UTF8 - encodings["us-ascii"] = gencoding.ASCII - encodings["ascii"] = gencoding.ASCII - encodings["iso646"] = gencoding.ASCII -} |