Burrows–Wheeler transform: Difference between revisions
Added Sidef
Thundergnat (talk | contribs) (Add source attribution, move Python specific verbiage to Python entry) |
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return s.rstrip("\003").strip("\002") # Get rid of start and end markers
</lang>
=={{header|Sidef}}==
{{trans|Python}}
<lang ruby>class BurrowsWheelerTransform (String L = "\002") {
method encode(String s) {
assert(!s.contains(L), "String cannot contain `#{L.dump}`")
s = (L + s)
s.len.of{|i| s.substr(i) + s.substr(0, i) }.sort.map{.last}.join
}
method decode(String s) {
var t = s.len.of("")
var c = s.chars
{ t = (c ~Z+ t).sort } * s.len
t.first { .begins_with(L) }.substr(L.len)
}
}
var tests = [
"banana", "appellee", "dogwood", "TOBEORNOTTOBEORTOBEORNOT"
"SIX.MIXED.PIXIES.SIFT.SIXTY.PIXIE.DUST.BOXES",
]
var bwt = BurrowsWheelerTransform(L: '$')
tests.each { |str|
var enc = bwt.encode(str)
var dec = bwt.decode(enc)
say "BWT(#{dec.dump}) = #{enc.dump}"
assert_eq(str, dec)
}</lang>
{{out}}
<pre>
BWT("banana") = "annb$aa"
BWT("appellee") = "e$elplepa"
BWT("dogwood") = "do$oodwg"
BWT("TOBEORNOTTOBEORTOBEORNOT") = "TOOOBBBRRTTTEEENNOOOOR$TO"
BWT("SIX.MIXED.PIXIES.SIFT.SIXTY.PIXIE.DUST.BOXES") = "STEXYDST.E.IXXIIXXSSMPPS.B..EE.$.USFXDIIOIIIT"
</pre>
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