25 lines
619 B
Nim
25 lines
619 B
Nim
import unsigned, strutils
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proc toSeq(x: uint64): seq[uint8] =
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var x = x
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result = @[]
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var f = 0
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for i in countdown(9, 1):
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if (x and (127'u64 shl uint((i * 7)))) > 0'u64:
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f = i
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break
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for j in 0..f:
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result.add(uint8((x shr uint64((f - j) * 7)) and 127) or 128)
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result[f] = result[f] xor 128'u8
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proc fromSeq(xs): uint64 =
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result = 0
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for x in xs:
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result = (result shl 7) or (x and 127)
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for x in [0x7f'u64, 0x4000'u64, 0'u64, 0x3ffffe'u64, 0x1fffff'u64,
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0x200000'u64, 0x3311a1234df31413'u64]:
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let c = toSeq(x)
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echo "seq from $#: $# back: $#".format(x, c, fromSeq(c))
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