Caesar cipher: Difference between revisions

=={{header|OmniMark}}==

<syntaxhighlight lang="omnimark">

; caesar.xom

global integer gi-k initial {13}

global stream gs-ed initial {'encode'}

global stream gs-phrase

define stream function apply-cipher (value stream phrase, value integer k, value stream ed) as

local integer b

local stream ciphered

open ciphered as buffer

repeat scan phrase

match letter => char

set b to char binary 0

increment b by k when ed = 'encode'

increment b by 26 - k when ed = 'decode'

decrement b by 26 when char matches uc and b > 90

decrement b by 26 when char matches lc and b > 122

put ciphered "b" % b

match any => char

put ciphered char

again

close ciphered

return ciphered

process

output apply-cipher(gs-phrase, gi-k, gs-ed) || '%n%n'

</syntaxhighlight>

{{out}}

<pre>

> omnimark -sb caesar.xom -c gi-k 2 -d gs-ed encode -d gs-phrase 'HI! The quick brown fox jumps over the lazy dog.'

JK! Vjg swkem dtqyp hqz lworu qxgt vjg ncba fqi.

> omnimark -sb caesar.xom -c gi-k 20 -d gs-ed encode -d gs-phrase 'HI! The quick brown fox jumps over the lazy dog.'

BC! Nby kocwe vliqh zir dogjm ipyl nby futs xia.

> omnimark -sb caesar.xom -c gi-k 2 -d gs-ed decode -d gs-phrase 'JK! Vjg swkem dtqyp hqz lworu qxgt vjg ncba fqi.'

HI! The quick brown fox jumps over the lazy dog.

> omnimark -sb caesar.xom -c gi-k 20 -d gs-ed decode -d gs-phrase 'BC! Nby kocwe vliqh zir dogjm ipyl nby futs xia.'

HI! The quick brown fox jumps over the lazy dog.

</pre>