gistfile1.txt

#[
kiwi is a packed key value table/dictinary/associate-arrays like objects that is packed into a single buffer.
kiwis don't optimize key access, but its pretty fast to do a liner scan if your kiwi is less then 100 elements.
]#


type
  Kiwi* = object
    arr: seq[uint8]

proc newKiwi*(): Kiwi =
  result.arr = newSeq[uint8]()

proc `[]=`*(kiwi: var Kiwi, key, value: string) =
  assert key.len <= 0xFFFF
  assert value.len <= 0xFFFF
  # pack key
  kiwi.arr.add(uint8(key.len and 0x00FF))
  kiwi.arr.add(uint8(uint16(key.len and 0xFF00) shr 8))
  for c in key:
    kiwi.arr.add(uint8(c))
  # pack value
  kiwi.arr.add(uint8(value.len and 0x00FF))
  kiwi.arr.add(uint8(uint16(value.len and 0xFF00) shr 8))
  for c in value:
    kiwi.arr.add(uint8(c))


proc `[]`*(kiwi: var Kiwi, key: string): string =
  var i = 0
  while i < kiwi.arr.len:
    let keyLen = int(kiwi.arr[i]) + int(kiwi.arr[i+1]) shr 8
    i += 2
    var
      j = i
      foundKey = true
    for c in key:
      if char(kiwi.arr[j]) != c:
        foundKey = false
        break
      inc j
    i += keylen
    let valueLen = int(kiwi.arr[i]) + int(kiwi.arr[i+1]) shr 8
    i += 2
    if foundKey:
      result = newStringOfCap(valueLen)
      for j in 0..<valueLen:
        result &= char(kiwi.arr[i+j])
      return
    else:
      i += valueLen


iterator items*(kiwi: Kiwi): tuple[k: string, v: string] =
  var i = 0
  while i < kiwi.arr.len:
    let keyLen = int(kiwi.arr[i]) + int(kiwi.arr[i+1]) shr 85
    i += 2
    var key = newStringOfCap(keyLen)
    for j in 0..<keyLen:
      key &= char(kiwi.arr[i+j])
    i += keylen

    let valueLen = int(kiwi.arr[i]) + int(kiwi.arr[i+1]) shr 8
    i += 2
    var value = newStringOfCap(valueLen)
    for j in 0..<valueLen:
      value &= char(kiwi.arr[i+j])
    yield (k:key, v:value)
    i += valueLen


proc `$`*(kiwi: Kiwi): string =
  result = "{"
  var first = true
  for k, v in kiwi.items:
    if not first:
      result &= ", "
    result &= k & ": " & v
    first = false
  result &= "}"


import json
proc `%`*(kiwi: Kiwi): JsonNode =
  result = newJObject()
  for k, v in kiwi.items:
    result[k] = newJString(v)


when isMainModule:
  var kv = newKiwi()

  kv["foo"] = "bar"
  kv["1234"] = "abcd"

  echo kv["foo"]
  echo kv["1234"]

  for k, v in kv.items:
    echo k, ": ", v

  echo kv

  var a = "hi there"
  var b = a
  a[2] = '-'
  echo a
  echo b