debounce.hs

来自「Cores are generated from Confluence a mo」· HS 代码 · 共 30 行

-- | Debouncing a boolean signal.
module Language.Atom.Common.Debounce
  ( debounce
  ) where

import Language.Atom
import Language.Atom.Common.Timer

-- | Debounces a boolean given a scope name, number of stable cycles, and an initial condition.
debounce :: Name -> Int -> Bool -> Term Bool -> System (Term Bool)
debounce name num init input = scope name $ do

  assert "positiveNumber" $ num >= 0

  state <- bool "state" init
  last  <- bool "last"  init
  count <- timer "count"

  rule "reset" $ do
    when $ input /=. value last
    start count num
    last <== input

  rule "update" $ do
    whenDone count
    state <== input

  return $ value state