Consistent overhead byte stuffing: Difference between revisions

::*   Decode an encoded stream, including error-check functionality.packet

(function COBS unencoded _encoded

encoded (append (first 254 chunk) (or %1_encoded []))

(ifwhen (or (< 254 length) (and (= length 254) more?) (> length 254)more?)

(recur (skip (min 254 (inc length)) unencoded) encoded))

function COBSencodecobs_encode(inputdata; reduced = false, marker = 0x00)

codeindex, lastindex, code = 1, 1, 1

if byte != marker0x00

if byte == marker0x00 || code == 255

push!(output, marker0x00)

output[codeindex] = marker0x00

return# Reduce size output of by 1 char if can

COBSdecodecobs_decode(buffer; reduced = false, marker = 0x00)

Return result of decoding `bufferinputdata` from COBS encodedor COBS/R packet format.

function COBSdecodecobs_decode(buffer::AbstractVector; reduced = false, marker = 0x00)

bdx, len = 1, length(bufferbuf)

code = bufferbuf[bdx]

for i_ in= 1:code-1

push!(decoded,byte buffer= buf[bdx])

if bdx >= len && break

code < 0xff && bdx < len && push!(decoded, marker0x00)

println(ab(t), " -> ", ab(COBSencodecencode(t, marker = 3)), " -> ", ab(COBSdecode(COBSencode(t, 3), 3)))

00 -> 0102 0102 0003 -> 00

00 00 -> 0102 0102 0102 0003 -> 00 00

00 11 00 -> 01 02 11 01 0012 02 03 -> 00 11 00

11 22 00 33 -> 0300 1112 2221 0201 3330 0003 -> 11 22 00 33

11 22 33 44 -> 0506 1112 2221 3330 4447 0003 -> 11 22 33 44

11 00 00 00 -> 0201 1112 0102 0102 0102 0003 -> 11 00 00 00

01 02 03 04 ... fb fc fd fe -> ff 01fc 02 0301 00 ... fc fdff fe 00fd 03 -> 01 02 03 04 ... fb fc fd fe

00 01 02 03 ... fb fc fd fe -> 0102 ff 01fc 02 01 ... fc fdff fe 00fd 03 -> 00 01 02 03 ... fb fc fd fe

01 02 03 04 ... fc fd fe ff -> ff 01fc 02 0301 00 ... fefd 0201 fffc 0003 -> 01 02 03 04 ... fc fd fe ff

02 03 04 05 ... fd fe ff 00 -> fffc 0201 0300 0407 ... fffc 0102 0102 0003 -> 02 03 04 05 ... fd fe ff 00

03 04 05 06 ... fe ff 00 01 -> fefd 0300 0407 0506 ... ff 02fc 01 0002 03 -> 03 04 05 06 ... fe ff 00 01

<span style="color: #008080;">function</span> <span style="color: #000000;">cobs_encode</span><span style="color: #0000FF;">(</span><span style="color: #004080;">sequencestring</span> <span style="color: #000000;">data</span><span style="color: #0000FF;">,</span> <span style="color: #004080;">integer</span> <span style="color: #000000;">delim</span><span style="color: #0000FF;">=</span><span style="color: #000000;">0</span><span style="color: #0000FF;">)</span>

<span style="color: #004080;">sequencestring</span> <span style="color: #000000;">bufferenc</span> <span style="color: #0000FF;">=</span> <span style="color: #0000FF008000;">{-</span><span style="color: #000000;?">1</span><span style="color: #0000FF;">}</span>

<span style="color: #004080;">integer</span> <span style="color: #000000;">cdxins</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">1</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">code</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">1</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">addlastaddLastCode</span> <span style="color: #0000FF;">=</span> <span style="color: #004600;">true</span>

<span style="color: #008080;">if</span> <span style="color: #000000;">b</span><span style="color: #0000FF;">!=</span><span style="color: #000000;">0</span> <span style="color: #008080;">then</span>

<span style="color: #000000;">bufferenc</span> <span style="color: #0000FF;">&=</span> <span style="color: #000000;">b</span>

<span style="color: #000000;">addlastaddLastCode</span> <span style="color: #0000FF;">=</span> <span style="color: #004600;">true</span>

<span style="color: #008080;">if</span> <span style="color: #000000;">b</span><span style="color: #0000FF;">==</span><span style="color: #000000;">0</span> <span style="color: #008080;">or</span> <span style="color: #000000;">code</span> <span style="color: #0000FF;">==</span> <span style="color: #000000;">0xFF255</span> <span style="color: #008080;">then</span>

<span style="color: #000000008080;">addlastif</span> <span style="color: #000000;">code</span><span style="color: #0000FF;">==</span><span style="color: #000000;">255</span> <span style="color: #008080;">then</span> <span style="color: #000000;">codeaddLastCode</span> <span style="color: #0000FF;">!=</span> <span style="color: #000000004600;">false</span> <span style="color: #008080;">end</span> <span style="color: #008080;">0xFFif</span>

<span style="color: #000000;">bufferenc</span><span style="color: #0000FF;">[</span><span style="color: #000000;">cdxins</span><span style="color: #0000FF;">]</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">code</span>

<span style="color: #000000;">bufferenc</span> <span style="color: #0000FF;">&=</span> <span style="color: #0000FF;">-</span><span style="color: #000000008000;">1'?'</span>

<span style="color: #000000;">cdxins</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">length</span><span style="color: #0000FF;">(</span><span style="color: #000000;">bufferenc</span><span style="color: #0000FF;">)</span>

<span style="color: #008080000000;">ifenc</span><span style="color: #0000FF;">[</span><span style="color: #000000;">addlastins</span><span style="color: #0000FF;">]</span> <span style="color: #0080800000FF;">=</span> <span style="color: #000000;">thencode</span>

<span style="color: #008080;">return</span> <span style="color: #000000;">bufferenc</span>

<span style="color: #008080;">function</span> <span style="color: #000000;">cobs_decode</span><span style="color: #0000FF;">(</span><span style="color: #004080;">sequencestring</span> <span style="color: #000000;">bufferenc</span><span style="color: #0000FF;">,</span> <span style="color: #004080;">integer</span> <span style="color: #000000;">delim</span><span style="color: #0000FF;">=</span><span style="color: #000000;">0</span><span style="color: #0000FF;">)</span>

<span style="color: #0040807060A8;">sequenceassert</span><span style="color: #0000FF;">(</span><span style="color: #000000;">dataenc</span> <span style="color: #0000FF;">[$]==</span><span style="color: #000000;">delim</span><span style="color: #0000FF;">{})</span>

<span style="color: #004080;">integer</span> <span style="color: #000000;">bdxenc</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">1enc</span><span style="color: #0000FF;">,[</span> <span style="color: #000000;">l</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">length1</span><span style="color: #0000FF;">(..-</span><span style="color: #000000;">buffer2</span><span style="color: #0000FF;">)]</span>

<span style="color: #008080004080;">whileinteger</span> <span style="color: #000000;">bdxl</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">length</span><span style="color: #0000FF;">(</span><span style="color: #000000;">lenc</span><span style="color: #0000FF;">),</span> <span style="color: #008080000000;">code</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">255</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">block</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">do0</span>

<span style="color: #008080;">if</span> <span style="color: #000000;">delim</span> <span style="color: #004080008080;">integerthen</span> <span style="color: #000000;">codeenc</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">sq_xor_bits</span><span style="color: #0000FF;">(</span><span style="color: #000000;">bufferenc</span><span style="color: #0000FF;">[,</span><span style="color: #000000;">bdxdelim</span><span style="color: #0000FF;">])</span> <span style="color: #008080;">end</span> <span style="color: #008080;">if</span>

<span style="color: #004080;">string</span> <span style="color: #000000;">bdxdata</span> <span style="color: #0000FF;">+=</span> <span style="color: #000000008000;">1""</span>

<span style="color: #008080;">for</span> <span style="color: #000000;">i</span><span style="color: #0000FF;">=</span><span style="color: #000000;">1</span> <span style="color: #008080;">to</span> <span style="color: #000000;">code</span><span style="color: #0000FF;">-</span><span style="color: #000000;">1l</span> <span style="color: #008080;">do</span>

<span style="color: #004080;">integer</span> <span style="color: #000000;">datab</span> <span style="color: #0000FF;">&=</span> <span style="color: #000000;">bufferenc</span><span style="color: #0000FF;">[</span><span style="color: #000000;">bdxi</span><span style="color: #0000FF;">]</span>

<span style="color: #008080;">if</span> <span style="color: #000000;">bdxblock</span> <span style="color: #0000FF;">+!=</span> <span style="color: #000000;">10</span> <span style="color: #008080;">then</span>

<span style="color: #008080000000;">enddata</span> <span style="color: #0000FF;">&=</span> <span style="color: #008080000000;">forb</span>

<span style="color: #7060A8;">assert</span><span style="color: #0000FF;">((</span><span style="color: #000000;">datai</span><span style="color: #0000FF;">+</span><span style="color: #000000;">b</span><span style="color: #0000FF;">&-</span><span style="color: #000000;">1</span><span style="color: #0000FF;">)<=</span><span style="color: #000000;">0l</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"marker pointing beyond the end of packet"</span><span style="color: #0000FF;">)</span>

<span style="color: #008080000000;">endblock</span> <span style="color: #0000FF;">-=</span> <span style="color: #008080000000;">while1</span>

<span style="color: #008080;">constantfunction</span> <span style="color: #000000;">tests</span> <span style="color: #0000FF;">=</span> <span style="color: #0000FF;">{{{</span><span style="color: #000000;">0x00</span><span style="color: #0000FF;">},</span> <span style="color: #0000FF;">{</span><span style="color: #000000;">0x01</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">0x01</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">0x00string00FF</span><span style="color: #0000FF;">}},()</span>

<span style="color: #0000FF004080;">{{</span><span style="color: #000000;">0x00</span><span style="color: #0000FF;">,string</span> <span style="color: #000000;">0x00</span><span style="color: #0000FF;">},res</span> <span style="color: #0000FF;">{</span><span style="color: #000000;">0x01</span><span style="color: #0000FF;">,</span> <span style="color: #000000008000;">0x01</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">0x01</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">0x00</span><span style="color: #0000FF;">}},</span>

<span style="color: #0000FF008080;">{{for</span> <span style="color: #000000;">0x00ch</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">0x11</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">0x00</span> <span style="color: #0000FF008080;">},to</span> <span style="color: #0000FF000000;">{0xFF</span><span style="color: #000000;">0x01</span><span style="color: #0000FF008080;">,do</span> <span style="color: #000000;">0x02res</span> <span style="color: #0000FF;">,&=</span> <span style="color: #000000;">0x11</span><span style="color: #0000FF;">,ch</span> <span style="color: #000000008080;">0x01</span><span style="color: #0000FF;">,end</span> <span style="color: #000000;">0x00</span><span style="color: #0000FF008080;">}},for</span>

<span style="color: #0000FF008080;">{constant</span><span style="color: #7060A8;">tagset</span><span style="color: #0000FF;">(</span><span style="color: #000000;">0xFEt00toFF</span><span style="color: #0000FF;">,</span><span style="color: #000000;">0x01</span><span style="color: #0000FF;">),</span> <span style="color: #7060A8;">flatten</span><span style="color: #0000FF;">({</span><span style="color: #000000;">0xFF</span><span style="color: #0000FF;">,</span> <span style="color: #7060A8;">tagsetstring00FF</span><span style="color: #0000FF;">(</span><span style="color: #000000;">0xFE</span><span style="color: #0000FF;">,</span><span style="color: #000000;">0x01</span><span style="color: #0000FF;">),</span> <span style="color: #000000;">0x00</span><span style="color: #0000FF;">})},</span>

<span style="color: #0000FF;">{</span><span style="color: #7060A8;">tagset</span><span style="color: #0000FF;">(</span><span style="color: #000000;">0xFEt00FE</span><span style="color: #0000FF;">,</span><span style="color: #000000;">0x00</span><span style="color: #0000FF;">),</span> <span style="color: #7060A8;">flatten</span><span style="color: #0000FF;">({</span><span style="color: #000000;">0x01t00toFF</span><span style="color: #0000FF;">,[</span> <span style="color: #000000;">0xFF1</span><span style="color: #0000FF;">,..-</span> <span style="color: #7060A8;">tagset</span><span style="color: #0000FF;">(</span><span style="color: #000000;">0xFE</span><span style="color: #0000FF;">,</span><span style="color: #000000;">0x01</span><span style="color: #0000FF;">),</span> <span style="color: #000000;">0x002</span><span style="color: #0000FF;">})}],</span>

<span style="color: #0000FF;">{</span><span style="color: #7060A8;">tagset</span><span style="color: #0000FF;">(</span><span style="color: #000000;">0xFFt01FE</span><span style="color: #0000FF;">,</span><span style="color: #000000;">0x01</span><span style="color: #0000FF;">),</span> <span style="color: #7060A8;">flatten</span><span style="color: #0000FF;">({</span><span style="color: #000000;">0xFFt00toFF</span><span style="color: #0000FF;">,</span> <span style="color: #7060A8;">tagset</span><span style="color: #0000FF;">([</span><span style="color: #000000;">0xFE2</span><span style="color: #0000FF;">,..-</span><span style="color: #000000;">0x01</span><span style="color: #0000FF;">),</span> <span style="color: #000000;">0x02</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">0xFF</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">0x002</span><span style="color: #0000FF;">})}],</span>

<span style="color: #0000FF;">{</span><span style="color: #7060A8;">tagset</span><span style="color: #0000FF;">(</span><span style="color: #000000;">0xFFt01FF</span><span style="color: #0000FF;">,</span><span style="color: #000000;">0x02</span><span style="color: #0000FF;">)</span> <span style="color: #0000FF;">&</span> <span style="color: #0000FF;">{</span><span style="color: #000000;">0x00t00toFF</span><span style="color: #0000FF;">},</span> <span style="color: #7060A8;">flatten</span><span style="color: #0000FF;">({[</span><span style="color: #000000;">0xFF2</span><span style="color: #0000FF;">,..-</span> <span style="color: #7060A8;">tagset</span><span style="color: #0000FF;">(</span><span style="color: #000000;">0xFF</span><span style="color: #0000FF;">,</span><span style="color: #000000;">0x02</span><span style="color: #0000FF;">),</span> <span style="color: #000000;">0x01</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">0x01</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">0x001</span><span style="color: #0000FF;">})}],</span>

<span style="color: #0000FF;">{</span><span style="color: #7060A8;">tagset</span><span style="color: #0000FF;">(</span><span style="color: #000000;">0xFFt02FF</span><span style="color: #0000FF;">,</span><span style="color: #000000;">0x03</span><span style="color: #0000FF;">)</span> <span style="color: #0000FF;">&</span> <span style="color: #0000FF;">{</span><span style="color: #000000;">0x00t00toFF</span><span style="color: #0000FF;">,[</span> <span style="color: #000000;">0x013</span><span style="color: #0000FF;">},</span> <span style="color: #7060A8;">flatten</span><span style="color: #0000FF;">({..-</span><span style="color: #000000;">0xFE1</span><span style="color: #0000FF;">],</span> <span style="color: #7060A8;">tagset</span><span style="color: #0000FF;">(</span><span style="color: #000000;">0xFF</span><span style="color: #0000FF;">,</span><span style="color: #000000;">0x03</span><span style="color: #0000FF;">),</span> <span style="color: #000000;">0x02</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">0x01</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">0x00</span><span style="color: #0000FF;">})}}</span>

<span style="color: #008080000000;">fort03FF</span> <span style="color: #0000000000FF;">t=</span> <span style="color: #008080000000;">int00toFF</span><span style="color: #0000FF;">[</span><span style="color: #000000;">tests4</span><span style="color: #0000FF;">..-</span><span style="color: #000000;">1</span><span style="color: #0080800000FF;">do],</span>

<span style="color: #004080;">sequence</span> <span style="color: #0000FF;">{</span><span style="color: #000000;">origtests</span> <span style="color: #0000FF;">,=</span> <span style="color: #0000000000FF;">expected{{</span><span style="color: #0000FF008000;">}x"00"</span> <span style="color: #0000FF;">=,</span> <span style="color: #000000008000;">tx"010100"</span><span style="color: #0000FF;">},</span>

<span style="color: #000000;">actual</span> <span style="color: #0000FF;">={</span> <span style="color: #000000008000;">cobs_encodex"0000"</span><span style="color: #0000FF;">(,</span> <span style="color: #000000008000;">origx"01010100"</span><span style="color: #0000FF;">)},</span>

<span style="color: #000000;">decoded</span> <span style="color: #0000FF;">={</span> <span style="color: #000000008000;">cobs_decodex"001100"</span><span style="color: #0000FF;">(,</span> <span style="color: #000000008000;">actualx"0102110100"</span><span style="color: #0000FF;">)},</span>

<span style="color: #004080;">string</span> <span style="color: #000000;">ostr</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">iff</span><span style="color: #0000FF;">(</span><span style="color: #7060A8;">length</span><span style="color: #0000FF;">(</span><span style="color: #000000;">orig</span><span style="color: #0000FF;">)<</span><span style="color: #000000;">5</span><span style="color: #0000FF;">?</span><span style="color: #7060A8;">join</span><span style="color: #0000FF;">(</span><span style="color: #000000;">orig</span><span style="color: #0000FF;">,{</span><span style="color: #008000;">x" 11220033"</span><span style="color: #0000FF;">,</span><span style="color: #000000;">fmt</span><span style="color: #0000FF;">:=</span><span style="color: #008000;">x"%02x031122023300"</span><span style="color: #0000FF;">)},</span>

<span style="color: #0000FF;">:</span><span style="color: #7060A8;">join</span><span style="color: #0000FF;">(</span><span style="color: #000000;">orig</span><span style="color: #0000FF;">[</span><span style="color: #000000;">1</span><span style="color: #0000FF;">..</span><span style="color: #000000;">3</span><span style="color: #0000FF;">],</span><span style="color: #000000;">fmt</span><span style="color: #0000FF;">:={</span><span style="color: #008000;">x"%02x11223344"</span><span style="color: #0000FF;">)&</span><span style="color: #008000;">" ... "</span><span style="color: #0000FF;">&</span><span style="color: #7060A8;">join</span><span style="color: #0000FF;">(</span><span style="color: #000000;">orig</span><span style="color: #0000FF;">[</span><span style="color: #000000;">253</span><span style="color: #0000FF;">..$],</span><span style="color: #000000;">fmt</span><span style="color: #0000FF;">:=</span><span style="color: #008000;">x"%02x051122334400"</span><span style="color: #0000FF;">))},</span>

<span style="color: #000000;">astr</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">iff</span><span style="color: #0000FF;">({</span><span style="color: #7060A8008000;">length</span><span style=x"color: #0000FF;11000000">(</span><span style="color: #000000;">actual</span><span style="color: #0000FF;">)<</span><span style="color: #000000;">7</span><span style="color: #0000FF;">?</span><span style="color: #7060A8;">join</span><span style="color: #0000FF;">(</span><span style="color: #000000;">actual</span><span style="color: #0000FF;">,</span><span style="color: #000000;">fmt</span><span style="color: #0000FF;">:=</span><span style="color: #008000;">x"%02x021101010100"</span><span style="color: #0000FF;">)},</span>

<span style="color: #0000FF;">:</span><span style="color: #7060A8;">join</span><span style="color: #0000FF;">({</span><span style="color: #000000;">actualt01FE</span><span style="color: #0000FF;">[,</span><span style="color: #000000;">1</span><span style="color: #0000FF;">..</span><span style="color: #000000;">40xFF</span><span style="color: #0000FF;">],</span><span style="color: #000000;">fmt</span><span style="color: #0000FF;">:=&</span><span style="color: #008000;">"%02x"</span><span style="color: #0000FF000000;">)&t01FE</span><span style="color: #008000;">" ... "</span><span style="color: #0000FF;">&</span><span style="color: #7060A8;">join</span><span style="color: #0000FF;">(</span><span style="color: #000000;">actual</span><span style="color: #0000FF;">[</span><span style="color: #000000;">254</span><span style="color: #0000FF;">..$],</span><span style="color: #000000;">fmt</span><span style="color: #0000FF;">:=</span><span style="color: #008000;">"%02x"0x00</span><span style="color: #0000FF;">))},</span>

<span style="color: #000000;">eOK</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">iff</span><span style="color: #0000FF;">({</span><span style="color: #000000;">actualt00FE</span><span style="color: #0000FF;">==,</span> <span style="color: #000000008000;">expectedx"01FF"</span> <span style="color: #0000FF;">?&</span> <span style="color: #008000000000;">"OK"t01FE</span> <span style="color: #0000FF;">:&</span> <span style="color: #008000000000;">"***???***"0x00</span><span style="color: #0000FF;">)},</span>

<span style="color: #000000;">dOK</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">iff</span><span style="color: #0000FF;">({</span><span style="color: #000000;">decodedt01FF</span><span style="color: #0000FF;">==,</span> <span style="color: #000000;">orig0xFF</span> <span style="color: #0000FF;">?&</span> <span style="color: #008000000000;">"OK"t01FE</span> <span style="color: #0000FF;">:&</span> <span style="color: #008000;">x"***???***02FF00"</span><span style="color: #0000FF;">)},</span>

<span style="color: #7060A8;">printf</span><span style="color: #0000FF;">(</span><span style="color: #000000;">1</span> <span style="color: #0000FF;">,{</span><span style="color: #008000000000;">"%-23s -&gt; %-33s encode:%s, decode: %s\n"t02FF</span> <span style="color: #0000FF;">,{&</span> <span style="color: #000000;">ostr0x00</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">astr0xFF</span> <span style="color: #0000FF;">,&</span> <span style="color: #000000;">eOKt02FF</span> <span style="color: #0000FF;">,&</span> <span style="color: #000000008000;">dOKx"010100"</span><span style="color: #0000FF;">}),</span>

00 00 -> 01 01 01 00 encode:OKtrue, decode: OKtrue

00 11 00 -> 01 02 1101 01 00 encode:OKtrue, decode: OKtrue

1100 2211 00 33 -> 0301 02 11 2201 00 02 33 00 encode:OKtrue, decode: OKtrue

11 22 00 33 44 -> 0503 11 22 3302 4433 00 encode:OKtrue, decode: OKtrue

11 0022 0033 0044 -> 0205 11 0122 0133 0144 00 encode:OKtrue, decode: OKtrue

0111 00 00 00 02 03 ... FD FE -> FF02 11 01 0201 01 00 03 ... FD FE 00 encode:OKtrue, decode: OKtrue

00 01 02 03 ... FC FD FE -> 01 FF 01 02 03 ... FC FD FE 00 encode:OKtrue, decode: OKtrue

00 01 02 03 ... FC FD FE FF -> 01 FF 01 02 03 ... FC FD FE 0200 FF 00 encode:OKtrue, decode: OKtrue

01 02 03 04 ... FD FE FF 00 -> FF 01 02 03 04 ... FD FE 02 FF 01 01 00 encode:OKtrue, decode: OKtrue

02 03 04 05 ... FE FF 00 01 -> FEFF 02 03 04 05 ... FE FF 0201 01 00 encode:OKtrue, decode: OKtrue

This only supports using a non-zero marker (seeusing the method suggested by Nigel Galloway in the talk page) which is also the method suggested in the original Cheshire & Baker paper.

<syntaxhighlight lang="ecmascriptwren">import "./fmt" for Fmt

static encode(data, delim) {

if (delim != 0) for (i in 0...enc.count) enc[insi] = 0enc[i] ^ delim

static decode(enc, delim) {

if (!((enc is List) && enc.count > 0 && enc[-1] == 0delim &&

Fiber.abort("encoded data must be a non-empty list of zerodelimiter-terminated bytes.")

for (bytei in enc[0..-2].length) {

varfor res = COBS.encode(example in examples) {

var re = Fmt.va("Xz", 2, resexample, 0, " ", "", "", 5, "...")

var r = Fmt.printva("$sXz", ->2, res, 0, " $s", e"", r"", 5, "...")

var res = COBS.decode if (enc.count < 7) {

var er = Fmt.va("Xz", 2, encres, 0, " ", "", "", 5, "...")

var r = Fmt.vaprint("Xz",$s 2, res, 0, "-> $s", ""e, "", 5, "..."r)

Fmt.print("$s -> $s", e, r)}

COBS encoding (hex) with delimiter 0x00:

COBS decoding (hex) with delimiter 0x00: