Metronome: Difference between revisions

=={{header|F Sharp|F#}}==

<lang fsharp>open System

open System.Threading

// You can use .wav files for your clicks.

// If used, make sure they are in the same file

// as this program's executable file.

let high_pitch =

new System.Media.SoundPlayer("Ping Hi.wav")

let low_pitch =

new System.Media.SoundPlayer("Ping Low.wav")

let factor x y = x / y

// Notice that exact bpm would not work by using

// Thread.Sleep() as there are additional function calls

// that would consume a miniscule amount of time.

// This number may need to be adjusted based on the cpu.

let cpu_error = -750.0

let print = function

| 1 -> high_pitch.Play(); "\nTICK "

| _ -> low_pitch.Play(); "tick "

let wait (time:int) =

Thread.Sleep(time)

// Composition of functions

let tick = (float>>factor (60000.0+cpu_error)>>int>>wait)

let rec play beats_per_measure current_beat beats_per_minute =

match current_beat, beats_per_measure with

| a, b ->

current_beat |> (print>>printf "%s")

beats_per_minute |> tick

if a <> b then

beats_per_minute |> play beats_per_measure (current_beat + 1)

[<EntryPointAttribute>]

let main (args : string[]) =

let tempo, beats = int args.[0], int args.[1]

Seq.initInfinite (fun i -> i + 1)

|> Seq.iter (fun _ -> tempo |> play beats 1 |> ignore)

0</lang>

Sample run:

<pre>$ metronome 120 6

TICK tick tick tick tick tick

TICK tick tick tick tick tick

TICK tick tick tick tick tick

TICK tick tick tick tick tick

TICK tick tick^C

</pre>