RosettaCodeData/Task/Binary-digits/Icon/binary-digits.icon

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procedure main()
every i := 5 | 50 | 255 | 1285 | 9000 do
write(i," = ",binary(i))
end
procedure binary(n) #: return bitstring for integer n
static CT, cm, cb
initial {
CT := table() # cache table for results
cm := 2 ^ (cb := 4) # (tunable) cache modulus & pad bits
}
b := "" # build reversed bit string
while n > 0 do { # use cached result ...
if not (b ||:= \CT[1(i := n % cm, n /:= cm) ]) then {
CT[j := i] := "" # ...or start new cache entry
while j > 0 do
CT[i] ||:= "01"[ 1(1+j % 2, j /:= 2 )]
b ||:= CT[i] := left(CT[i],cb,"0") # finish cache with padding
}
}
return reverse(trim(b,"0")) # nothing extraneous
end