Honk

First off, install the library if you haven’t done so already. This will be really hard to follow if you don’t ;)

First steps

The basic unit in Honk is the Note. A note has a duration and a frequency. You play the note using the playOne function.

To start off, we’ll create a program that beeps an A for one second. Type the following code your favorite text editor and save it as “OneBeep.hs”:

import Sound.Honk
main = playOne (Note 1 440)

Now run it:

runghc OneBeep.hs

You should hear a nice long beep coming from inside your computer.

Try changing the “440” to other numbers. How does it sound? If you’re more musically inclined, there is a very helpful table of frequencies you can use to find the right number. It’s impossible to break anything, so feel free to experiment.

Linux issues

If you use Linux, you’ll probably get this message:

*** Exception: beepDo: permission denied (Operation not permitted)

This is because under Linux, for security reasons, only the root user can control the PC speaker.

To fix this problem, just run it under sudo. For example, you would run the above example like so:

sudo runghc OneBeep.hs

Creating a melody

Of course, most music consists of more than one note. Fortunately, Honk’s incredibly well thought out design allows for this using the play function.

Save the following code in a file named “Airport.hs”:

import Sound.Honk
main = play [ Note 0.5 261.6, Note 0.5 329.6, Note 0.5 392.0
            , Note 1.5 532.3 ]

The end of the beginning

After this brief tutorial, I hope you’ve learned a fair bit about Honk! Honk itself is very simple, but the language behind it can be both powerful and intimidating. The examples page may provide inspiration for the curious.