gistfile1.txt

.sub 'infix:-' :multi('CardinalArray','CardinalArray')
    .param pmc this
    .param pmc that
    .local pmc array, hash, key, includes
    .local int i, len

    array = new 'CardinalArray'
    hash = new 'CardinalHash'
    len = that.'size'()
    i = 0

  hash_loop:
    if i == len goto hash_done

    key = that[i]
    hash[key] = 1

    i = i + 1
    goto hash_loop

  hash_done:
    len = this.'size'()
    i = 0

  diff_loop:
    if i == len goto diff_done
    
    key = this[i]
    includes = hash.'includes?'(key)

    unless includes goto diff_loop

    array.'push'(key)

    goto diff_loop
  
  diff_done:
    .return (array)
.end