gistfile1.nim

import zlib

proc compress(source: string): string =
  var
    sourcelen = source.len
    destlen = sourcelen + (sourcelen.float * 0.1).int + 16
  result = ""
  result.setLen destLen
  var res = zlib.compress(cstring(result), addr destLen, cstring(source), sourceLen)
  if res != Z_OK:
    echo "Error occured: ", res
  elif destLen < result.len:
    result.setLen(destLen)

proc uncompress(source: string): string =
  var
    sourceLen = source.len
    destLen = sourceLen + (sourcelen * 100).int + 64
  result = ""
  result.setLen destLen
  var res = zlib.uncompress(cstring(result), addr destLen, cstring(source), sourceLen)
  if res != Z_OK:
    echo "Error occured: ", res
  elif destLen != result.len: #this should always happen
    result.setLen destLen

when isMainModule:
  import strutils
  var r = compress("Hello")
  echo repr(r)
  var rr = uncompress(r)
  echo repr(rr)
  assert rr == "Hello"

  proc `*`(a: string; b: int): string {.inline.} = result = repeatStr(b, a)
  var s = "yo dude sup bruh homie" * 50
  r = compress(s)
  echo s.len, " -> ", r.len

  rr = uncompress(r)
  echo r.len, " -> ", rr.len
  assert rr == s