70 lines
1.3 KiB
Text
70 lines
1.3 KiB
Text
|
#lang scribble/manual
|
||
|
|
@(require (for-label racket))
|
||
|
|
|
||
|
|
@title{Pif}
|
||
|
|
Pattern-based conditional expression@section{related}
|
||
|
|
Classes/Pwhile
|
||
|
|
@section{categories}
|
||
|
|
Streams-Patterns-Events>Patterns>Language Control
|
||
|
|
|
||
|
|
@section{ClassMethods}
|
||
|
|
|
||
|
|
|
||
|
|
@section{method}
|
||
|
|
new
|
||
|
|
|
||
|
|
@section{argument}
|
||
|
|
condition
|
||
|
|
A pattern or stream returning a link::Classes/Boolean:: value.
|
||
|
|
|
||
|
|
@section{argument}
|
||
|
|
iftrue
|
||
|
|
This stream is evaluated if the link::Classes/Boolean:: is true.
|
||
|
|
|
||
|
|
@section{argument}
|
||
|
|
iffalse
|
||
|
|
This stream is evaluated if the link::Classes/Boolean:: is false.
|
||
|
|
|
||
|
|
@section{argument}
|
||
|
|
default
|
||
|
|
This value (not stream) is returned if "iftrue" or "iffalse" return nil at any time.
|
||
|
|
|
||
|
|
@section{Examples}
|
||
|
|
|
||
|
|
|
||
|
|
|
||
|
|
@racketblock[
|
||
|
|
p = Pif(Pfunc({ 0.3.coin }), Pwhite(0, 9, inf), Pwhite(100, 109, inf)).asStream;
|
||
|
|
p.nextN(20);
|
||
|
|
|
||
|
|
// 7 of the 20 values, or roughly 30%, are in the 0-9 range:
|
||
|
|
|
||
|
|
[ 105, 107, 107, 8, 100, 3, 105, 5, 107, 106, 1, 104, 8, 102, 102, 4, 108, 8, 109, 101 ]
|
||
|
|
|
||
|
|
|
||
|
|
// sound example
|
||
|
|
(
|
||
|
|
SynthDef(\help_sinegrain,
|
||
|
|
{ arg out=0, freq=440, sustain=0.05;
|
||
|
|
var env;
|
||
|
|
env = EnvGen.kr(Env.perc(0.01, sustain, 0.2), doneAction: Done.freeSelf);
|
||
|
|
Out.ar(out, SinOsc.ar(freq, 0, env))
|
||
|
|
}).add;
|
||
|
|
)
|
||
|
|
|
||
|
|
|
||
|
|
(
|
||
|
|
var a;
|
||
|
|
a = Pif(Pfunc({ 0.3.coin }), Pn(Pseries(0.5, 0.1, 10)), Pn(Pseries(6, -0.1, 10))).asStream;
|
||
|
|
{
|
||
|
|
loop {
|
||
|
|
Synth(\help_sinegrain, [\freq, a.next * 600 + 300]);
|
||
|
|
0.2.wait;
|
||
|
|
}
|
||
|
|
}.fork;
|
||
|
|
)
|
||
|
|
::
|
||
|
|
]
|
||
|
|
|
||
|
|
|