# input_edge.ludic — Input.key_pressed / key_released edge detection (#87). A
# handler game reads the press and release edges of a key in its Update phase; the
# frame loop commits the device layer itself (#83), so the game does NOT call
# Input.poll by hand, and the edges fire on exactly the transition frame. (The bug:
# a manual Input.poll under the loop used to double-commit and copy in_held into
# in_prev twice, so key_pressed/key_released never fired.)
#
# Driven headless by the keys on stdin, one char per frame. With "xkkxq":
#   x   frame0 — nothing
#   k   frame1 — pressed edge (down + just went down)
#   k   frame2 — held (down, no edge)
#   x   frame3 — released edge (was k, now not)
#   q   frame4 — nothing, then quit
#
# Run:  printf 'xkkxq' | bin/ludic examples/library/input_edge.ludic   ->  0 11 1 100 0
program InputEdge {
  property Tag { n: int = 0 }
  model P { Tag }

  handler In phase Update {
    var v = 0
    if Input.key_down('k')     { v = v + 1 }       # held
    if Input.key_pressed('k')  { v = v + 10 }      # went down this frame
    if Input.key_released('k') { v = v + 100 }     # went up this frame
    print(v)
  }
}