FAUST (programming language): Difference between revisions

Revision as of 22:55, 28 March 2015

Revision as of 12:17, 27 June 2015

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FAUST is a textual language but nevertheless block-diagram oriented. It actually combines two approaches: functional programming and algebraic block-diagrams. The key idea is to view block-diagram construction as function composition. For that, FAUST relies on a ''block-diagram algebra'' of five composition operations.

==SimpleExample examplesCode==

Let’sFAUST startprograms withdefine somea really<code>process</code> simplefunction one-linethat examplesoperates ofon FAUSTincoming programdata. HereThe isfollowing ais firstan example that produces silence:

<source lang=cpphaskell>

process = 0;

</source>

The second example is a little bit more sophisticated and copies the input signal to the output signal. It involves the <code>_ (underscore)</code> primitive that denotes the [[identity function]] on signals (that is a simple audio cable for a sound engineer):

<source lang=cpphaskell>

process = _;

</source>

Another very simple example is the conversion ofconverts a two-channel stereo signal into a one-channel mono signal using the <code>+</code> primitive that adds two signals together:

<source lang=cpphaskell>

process = +;

</source>

[[File:Faust-simple-block-diagram.jpg|thumb|Block-diagrams generated by Faust from some simple programs]]

Most FAUST primitives are analogous to their C counterpart on numbers, but lifted to signals. For example, the FAUST primitive <code>sin</code> operates on a signal X by applying the [[C (Programming Language)|C]] function <code>sin</code> to each sample X([t) of X. In other words sin transforms an input signal X into an output signal Y such that Y (t) = sin(X(t))]. All C numerical functions have their counterpart in FAUST.

Some [[signal processing]] primitives are specific to FAUST. For example the delay operator <code>@</code> takes two input signals: X (the signal to be delayed) and D (the delay to be applied), and produces an output signal Y such that Y (t) = X(t − D(t)).

==Block-diagram composition==