Improve zstring 10bit zscii de/en coding

Author: danieledapo

gork/zmemory.go

@@ -150,8 +150,6 @@ func (zmem *ZMemorySequential) DecodeZString(header *ZHeader) string {
 
 if alphabet == 2 && code == 0 {
 asciiPart = 1
-} else if alphabet == 2 && code == 1 {
-ret += "\n"
 } else {
 ret += string(Alphabets[alphabet][code])
 }
@@ -202,8 +200,10 @@ func ZStringEncode(what string) [encodedZstringLen]uint16 {
 }
 
 if i < 0 {
-// :)
-i = strings.IndexByte(Alphabets[2], '?')
+// 10 bit zscii
+writeChar(0x06)
+writeChar(what[c] >> 5)
+writeChar(what[c] & 0x1F)
 }
 
 writeChar(byte(i + 6))

gork/zmemory_test.go

@@ -3,7 +3,6 @@ package gork
 import (
 "encoding/binary"
 "fmt"
-"strings"
 "testing"
 )
 
@@ -33,13 +32,15 @@ var encodedZstrings []string = []string{
 "i",
 "42,",
 "$",
+"\n",
 }
 var encodedZstringsExpected [][]uint16 = [][]uint16{
 []uint16{0x7E97, 0xC0A5},
 []uint16{0x23C8, 0xC695},
 []uint16{0x38A5, 0x94A5},
 []uint16{0x1585, 0xA8B3},
-[]uint16{0x16A5, 0x94A5},
+[]uint16{0x14C1, 0x90A5},
+[]uint16{0x14E5, 0x94A5},
 }
 
 var byteOrder binary.ByteOrder = binary.BigEndian
@@ -238,7 +239,6 @@ func TestZStringEncode(t *testing.T) {
 
 for i := range encoded {
 if encoded[i] != expected[i] {
-fmt.Printf("%X %X\n", encoded[i], expected[i])
 t.Fail()
 }
 
@@ -251,23 +251,8 @@ func TestZStringEncode(t *testing.T) {
 seq := ZMemory(buf)
 decoded := seq.DecodeZStringAt(0, nil)
 
-for j := range decoded {
-ch := decoded[j]
-
-// default value if not found
-expCh := byte('?')
-
-for _, alph := range Alphabets {
-if strings.IndexByte(alph, ch) >= 0 {
-expCh = ch
-break
-}
-}
-
-if ch != expCh {
-t.Fail()
-}
-
+if decoded != zstr {
+t.Fail()
 }
 }