A FunctionList is a function that composes multiple functions into one. This allows allow to deal transparently with several functions as if they were one and to append new functions at a later point. The functions are evaluated in the order they have in the FunctionList's array, which is by default the order in which they have been added to it.
See the Functions help file for a basic introduction.
a = FunctionList.new;fork { loop { 0.7.wait; a.value.postln } };a.addFunc({ 800.rand });a.addFunc({ "another".scramble });create a new instance.
| functions |
An array of functions or objects |
Set/get the FunctionList's array. New functions can be added to the array directly, e.g.
xxxxxxxxxxx = FunctionList(...some functions);x.array = x.array.insert(2, aFunction);This message is used to be able to add to an Object, to a Function, or to a FunctionList. nil.addFunc returns a function, if only one function is passed in the argument. function.addFunc then returns a FunctionList.
remove a function from the list.
the last function when only one function is left, or nil when the last function was removed.
addFunc and removeFunc are implemented for Nil, Object and FunctionList
xxxxxxxxxxnil.addFunc(f) // returns fobj.addFunc(f) // returns FunctionList([obj, f])nil.removeFunc(f) // returns nilobj.removeFunc(f) // returns nil, if f === obj, else obj is returned// examplea = nil;a = a.addFunc { |x="", y=""| "this % is an % example\n".postf(x, y); 1 };a.postln;a = a.addFunc { |x="", y=""| "there is no % that is %\n".postf(x, y); 2 };a.value;a.value("text", "extraordinary well written")a.valueArray(["x", "y"]);xxxxxxxxxx// Function:do vs FunctionList:do (same)a.do { |x| x.value };{ 4 }.do { |x| x.value.postln }(().use { ~x = "array"; ~y = "ominous"; a.valueEnvir; a.valueEnvir("list");})xxxxxxxxxx// removing a functionx = { "removal test".postln };a.addFunc(x);a.value;a = a.removeFunc(x);a.value;// mathematicsa = nil;a = a.addFunc({ 1.0.rand }).addFunc({ [0, 1].choose });a = a.squared.linexp(0, 1, 1.0, 500);a.value;xxxxxxxxxx// compatibility with function multichannel expansiona = nil;a = a.addFunc { |x=0| if(x > 0) { 7 } { 1000.rand } };a = a.addFunc { |x=0| if(x < 0) { 17 } { -1000.rand } };a.valuea = a.flop;a.valuea.value([-1, 1])xxxxxxxxxx// typical usage in a Document action// see also SCView: addAction example.d = Document.current;d.keyDownAction = { "You touched the keyboard.".postln };d.keyDownAction = d.keyDownAction.addFunc {:x, x<-(1..), :: "already % times\n\n".postf(x) };d.keyDownAction = nil;// even if you don't know if there is already an action defined// one can add one.(d.keyDownAction = nil;d.keyDownAction = d.keyDownAction.addFunc {:x, x<-(1..), :: "already % times\n\n".postf(x) };);d.keyDownAction = nil;