key_map = { sequence ->
  kv_list = (list
    "" "escape"
    "[A" "up"
    "[B" "down"
    "[C" "right"
    "[D" "left"
    "[OP" "f1"
    "[OQ" "f2"
    "[OR" "f3"
    "[OS" "f4"
    "[15~" "f5"
    "[17~" "f6"
    "[18~" "f7"
    "[19~" "f8"
    "[20~" "f9"
    "[21~" "f10"
    "[24~" "f12"
    "OP" "f1"
    "OQ" "f2"
    "OR" "f3"
    "OS" "f4"
  )

  key = (if (greater_than (length sequence) 1) {
      <- (get sequence 1 (length sequence))
    } {
      <- ""
  })
  pos = (find kv_list key)
  value = (if (is pos void) {<-void} {<- (get kv_list (add pos 1))})

  <- (if (is value void) {<- ""} {<- value})
}

// starts the event loop
// returns the final state
start = { state listeners ->

  reduce_listeners = { event_index ->
    <- (reduce listeners { new_state listener listener_index ->
      <- (if (is listener void) {
        <- new_state
      } {
        fn = (get listener event_index)
        <- (if (is fn void) {
          <- new_state
        } {
          // fn is working on scope variable named state
          // update it to what was previously reduces
          state = new_state
          <- (if (is void state) {
            <- void
          } {
            <- (fn)
          })
        })
      })
    } state)
  }

  // ** event loop
  result = (until void {state loop_count ->
    // save state
    prev_state = state
    // get current event
    curr = (event)

    // loop "synthetic event"
    state = (reduce_listeners 1)

    // keypress
    state = (if (and (greater_than (length curr) 0) (less_than (length curr) 6)) {
      keypress_name = (if (not (is (get curr 0) "\e")) {
        <- (if (is curr "\x7f") {
          <- "delete"
        } {
          <- curr
        })
      } {
        <- (key_map curr)
      })

      <- (reduce_listeners 2)
    } {<- state})

    // mouse
    state = (if (greater_than (length curr) 6) {
        // base
        // 0, 1, 2 - mouse button clicked (generally from left to right)
        // 32 move - (35 means 32 + 3 button is "released")
        // 64 scroll up  (64 means 64 + 0 button is pressed, thus scroll)
        // modifiers
        // +4 shift
        // +8 meta
        // +16 control
        // e.g
        // [<35;12;7M

        <- (if (is (get curr 1 3) "[<") {
          first_delimiter = (find curr ";")

          mouse_code = (integer (get curr 3 first_delimiter))
          mouse_row_column = (get curr (add first_delimiter 1) (subtract (length curr) 1))

          second_delimiter = (find mouse_row_column ";")

          mouse_xy = (list 
            (subtract (integer (get mouse_row_column 0 second_delimiter)) 1)
            (subtract (integer (get mouse_row_column (add 1 second_delimiter) (length mouse_row_column))) 1)
          )

          // mouse move
          state = (reduce_listeners 3)

          // mouse click (with modifiers)
          state = (if (or 
            (is mouse_code 0)
            (is mouse_code 4)
            (is mouse_code 8)
            (is mouse_code 16)
            (is mouse_code 32)
            (is mouse_code 36)
            (is mouse_code 40)
            (is mouse_code 48)
          ) {
            <- (reduce_listeners 4)
          } {<- state})

          <- state
        } {<- state})
    } {<- state})

    // state "synthetic event"
    state = (if
      (not (is prev_state state)
    ) {
      <- (reduce_listeners 0)
    }{
      <- state
    })

    <- state
  } state)

  <- result
}