on script load:
  import "com.sk89q.worldedit.regions.CuboidRegion"
  import "com.sk89q.worldedit.Vector" as {WorldEditVector}
  import "com.sk89q.worldedit.EditSession"
  import "com.boydti.fawe.FaweAPI"
  import "com.boydti.fawe.util.EditSessionBuilder"
  import "com.sk89q.worldedit.blocks.BaseBlock"
  import "com.sk89q.worldedit.patterns.BlockChance"
  import "java.util.Arrays"
  import "com.sk89q.worldedit.patterns.RandomFillPattern"
  import "java.util.stream.Collectors"

function getRegion(pos1: location, pos2: location) :: object:
  loop 1 and 2:
    set {_vec::%loop-num%} to new {WorldEditVector}(x-loc of {_pos%loop-num%}, y-loc of {_pos%loop-num%} and z-loc of {_pos%loop-num%})
  return new {CuboidRegion}({_vec::*})

function getBaseBlock(block: itemtype) :: object:
  return new {BaseBlock}({_block}.getRandom().getTypeId() and {_block}.getRandom().getData().getData())

function getBlockChance(block: itemtype, chance: number) :: object:
  return new {BlockChance}(getBaseBlock({_block}) and {_chance})

function getWorld(world: world) :: object:
  return {FaweAPI}.getWorld("%{_world}%")

function getEditSession(world: world) :: object:
  return new {EditSessionBuilder}(getWorld({_world})).fastmode(true).build()

function replaceBlocks(pos1: location, pos2: location, blocks: itemtypes, block: object) :: boolean:
  set {_session} to getEditSession(world of {_pos1})
  set {_args::*} to getRegion({_pos1}, {_pos2})
  loop {_blocks::*}:
    add getBaseBlock(loop-value) to {_baseBlocks::*}
    add {Arrays}.stream([{_baseBlocks::*} as {BaseBlock}]).collect({Collectors}.toSet()) to {_args::*}
  if {_block} is a text:
    loop split {_block} at ",":
      set {_it::*} to join (split loop-value at "%%") with " " parsed as "%integer% %item%"
      if {_it::*} is set:
        add getBlockChance({_it::2}, {_it::1}) to {_c::*}
        delete {_it::*}
      else:
        return false
    add new {RandomFillPattern}({Arrays}.stream([{_c::*} as {BlockChance}]).collect({Collectors}.toList())) to {_args::*}
  else:
    add getBaseBlock({_block}) to {_args::*}
  {_session}.replaceBlocks({_args::*});
  {_session}.flushQueue();
  return true