more refactoring

Author: quackduck

README.md

@@ -59,22 +59,25 @@ Head over to [releases](https://github.com/quackduck/aces/releases) and download
 Aces - Encode in any character set
 
 Usage:
-   aces <charset>               - encode data from STDIN into <charset>
-   aces -d/--decode <charset>   - decode data from STDIN from <charset>
-   aces -h/--help               - print this help message
-
-Aces reads from STDIN for your data and outputs the result to STDOUT. The charset length must be
-a power of 2. While decoding, bytes not in the charset are ignored. Aces does not add any padding.
-```
-## Examples
-```shell
-echo hello world | aces "<>(){}[]" | aces --decode "<>(){}[]"      # basic usage
-echo matthew stanciu | aces HhAa | say                             # make funny sounds (macOS)
-aces " X" < /bin/echo                                              # see binaries visually
-echo 0100100100100001 | aces -d 01 | aces 01234567                 # convert bases
-echo Calculus | aces 01                                            # what's stuff in binary?
-echo Aces™ | base64 | aces -d
-ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/   # even decode base64
+  aces <charset>               - encode data from STDIN into <charset>
+  aces -d/--decode <charset>   - decode data from STDIN from <charset>
+  aces -h/--help               - print this help message
+
+  Aces reads from STDIN for your data and outputs the result to STDOUT. An optimized algorithm is used
+  for character sets with a power of 2 length. Newlines are ignored when decoding.
+
+Examples:
+  echo hello world | aces "<>(){}[]" | aces --decode "<>(){}[]"      # basic usage
+  echo matthew stanciu | aces HhAa | say                             # make funny sounds (macOS)
+  aces " X" < /bin/echo                                              # see binaries visually
+  echo 0100100100100001 | aces -d 01 | aces 0123456789abcdef         # convert bases
+  echo Calculus | aces 01                                            # what's stuff in binary?
+  echo Aces™ | base64 | aces -d
+  ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/   # even decode base64
+  echo -n uwonsmth | aces 🥇🥈🥉                                    # emojis work too! 
+  Set the encoding/decoding buffer size with --bufsize <size> (default 16KiB).
+
+  File issues, contribute or star at github.com/quackduck/aces
 ```
 
 ## How does it work?

aces.go

@@ -291,13 +291,13 @@ func (c *anyCoding) SetByteChunkSize(size int) {
 func (c *anyCoding) SetBufferSize(bufSize int) { c.bufSize = bufSize }
 
 func (c *anyCoding) Encode(dst io.Writer, src io.Reader) error {
-	//br := bufio.NewReaderSize(src, c.bufSize)
 	result := make([]rune, 0, c.bufSize)
 	buf := make([]byte, c.chunkSize)
-	endWrite := func(n int) error { // endWrite takes the number of bytes that were just read, encodes it and writes to dst.
-		result = append(result, encodeByteChunk(c.charset, buf, c.rPerChunk)...)
-		result = append(result, toBase(bytesToInt([]byte{byte(n)}), make([]rune, 0, 8), c.charset)...)
-		_, err := dst.Write([]byte(string(result)))
+	endWrite := func(n int) error { // endWrite takes the number of bytes that were just read, encodes it and writes to dst. This allows the decoder to trim the last chunk down to the right size.
+		_, err := dst.Write([]byte(string(append(append(
+			result,
+			encodeByteChunk(c.charset, buf, c.rPerChunk)...),
+			toBase(bytesToInt([]byte{byte(n)}), make([]rune, 0, 8), c.charset)...))))
 		return err
 	}
 	for {
@@ -309,7 +309,6 @@ func (c *anyCoding) Encode(dst io.Writer, src io.Reader) error {
 			return err
 		}
 		if err == io.ErrUnexpectedEOF { // end of data, not a multiple of chunk size.
-			// encode how many bytes of this chunk to keep
 			if err = endWrite(n); err != nil {
 				return err
 			}
@@ -349,8 +348,6 @@ func decodeToByteChunk(set []rune, runes []rune, chunkSize int) ([]byte, error)
 	if err != nil {
 		return nil, err
 	}
-	//println(num.String())
-	//fmt.Println(num.String())
 	return num.FillBytes(make([]byte, chunkSize)), nil
 }