Add example case for registering encodings.

fixes #583

encoding.go

@@ -1,4 +1,4 @@
-// Copyright 2015 The TCell Authors
+// Copyright 2022 The TCell Authors
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use file except in compliance with the License.
@@ -46,7 +46,7 @@ var encodingFallback EncodingFallback = EncodingFallbackFail
 // 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
+// For POSIX systems, this 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:
 //
@@ -64,9 +64,12 @@ var encodingFallback EncodingFallback = EncodingFallbackFail
 // 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.
+// superset of Unicode) and so the application size can be expected to
+// increase quite a bit as each encoding is added.
+
+// The East Asian encodings have been seen to add 100-200K per encoding to the
+// size of the resulting binary.
+//
 func RegisterEncoding(charset string, enc encoding.Encoding) {
 	encodingLk.Lock()
 	charset = strings.ToLower(charset)
@@ -74,7 +77,7 @@ func RegisterEncoding(charset string, enc encoding.Encoding) {
 	encodingLk.Unlock()
 }
 
-// EncodingFallback describes how the system behavees when the locale
+// EncodingFallback describes how the system behaves 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
@@ -87,7 +90,7 @@ const (
 	// when it cannot find an encoding.
 	EncodingFallbackFail = iota
 
-	// EncodingFallbackASCII behaviore causes GetEncoding to fall back
+	// EncodingFallbackASCII behavior causes GetEncoding to fall back
 	// to a 7-bit ASCII encoding, if no other encoding can be found.
 	EncodingFallbackASCII
 

encoding_test.go

@@ -0,0 +1,28 @@
+// Copyright 2022 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 (
+	"fmt"
+
+	"golang.org/x/text/encoding/simplifiedchinese"
+)
+
+func ExampleRegisterEncoding() {
+	RegisterEncoding("GBK", simplifiedchinese.GBK);
+	enc := GetEncoding("GBK");
+	glyph, _ := enc.NewDecoder().Bytes([]byte{0x82, 0x74})
+	fmt.Println(string(glyph))
+	// Output: 倀
+}