September 2008 - chuck-users - lists.cs.princeton.edu

Assigning to appended array locations (bug?)
by Kassen 28 Sep '08

28 Sep '08

Fellow ChucKists, I believe the code below demonstrates at least one bug that's keeping Mike from enjoying his spaghetti. There are definitely more related issues here but this is one. Appended non-primitive array locations can't be assigned to; clearly these are somehow different from array locations created when the array was created. Not creating a explicit "new" instance and instead appending a different instance directly also leads to reference issues, quite probably these are related. ================================= class Foo { int value; } Foo foo[8]; Foo bar; bar @=> foo[7]; foo << new Foo; <<<"all is fine so far", "">>>; Foo baz; <<<"everybody crash ChucK tonight", "">>>; baz @=> foo[8]; ================================ Yours, Kas.

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upper-case class (bug)
by Kassen 28 Sep '08

28 Sep '08

Dear list, For today's bonus-bug; This is simply a syntax error; class foo; This on the other hand crashes outright; Class foo; This on the other hand gets picked up by the parser as there is no type "Bar" defined; Bar foo; Kinda trivial but still a crash. Kas.

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Re: [chuck-users] Object reference weirdness
by Tiemen Meerman 28 Sep '08

28 Sep '08

In the meantime, what exactly is a bus error? What generally causes them? Bus errors can be caused by memory accesses that are misaligned: ie. a 32 bit read off of an odd memory address. Sounds like some pointer arithmetic going wrong somewhere in ChucK. -T

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crash caused by definition order (bug)
by Kassen 25 Sep '08

25 Sep '08

Dear list, Consider the following; ============================== spork ~foo(); me.yield(); Gain dest; fun void foo() { Gain source => dest; } ================================== Note that this is incorrect, I should have defined "dest" before sporking foo but mistakes are made... This code crashes my Mini (compiled with the latest ChucK so non canonical) on Linux outright (the whole thing just disapears). Variations on this theme under the canonical Windows version gave a "nullpointer Ugen connection" error and just exited the shred. Sadly I didn't have the time to document that exact permutation under win yesterday due to stress about a deadline. The parser does correctly catch this; =============================== fun void foo() { Gain source => dest; } spork ~foo(); me.yield(); Gain dest; ========================== ..but on a functional level that's the same, the place where a function is defined doesn't (well, *shouldn't*) matter; I like to keep mine at the bottom of the file below classes unless it's a especially large function that's especially fundamental for the structure of the program. Yours, Kas.

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Object reference weirdness
by mike clemow 25 Sep '08

25 Sep '08

I have an array of objects that I've created and I'm abstracting arrays of these objects as a class of its own right. While testing my code I've run into some weird snags. I would get bus errors when calling a print() function, which is supposed to just print to the screen the values of the object's members. I've been trying to track this down and then ran into a situation where I am instantiating a brand new object and changing it's member values (without adding it to the array). Whenever I change it's values, a certain object in my array changes with it--it's reference is identical to the new one I just created. This is like a warp in spacetime somewhere. My object is some quantum object that has a twin and is being changed instantaneously but at a distance. Schrodinger's cat is rolling over in its grave. (kidding). What is happening here? Is this a garbage collection issue? I will send my code (and instructions on running it) to anyone who wants to take a look, but I'm afraid of subjecting the entire list to my spaghetti... ;-) -mike -- http://semiotech.org http://semiotech.org/michael

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STK shakers wrench rattling?
by Kassen 23 Sep '08

23 Sep '08

Hi, list! I'm having a bit of a problem with the wrench and guiro presets of Shakers; they won't rattle nicely. That is; they do for the first .noteOn() after the preset was set but after that the following noteOn's merely make them click. I tried all parameters in lots of permutations, I also tried to understand the source (which has lots of exceptions for these two) but it's beyond me and some of the comments look scary ;¬). I'm suspecting this isn't proper behaviour; sometimes messing with the .energy() parameter will get them to make some sort of noise but no nice rattles. Could somebody please comment on this? Yours, Kas.

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int *=> dur (syntax inconsistency?)
by Kassen 21 Sep '08

21 Sep '08

Dear list, Consider; =================================== //definition second => dur foo; //this is fine 2.0 *=> foo; //this is not fine 2 *=> foo; ==================== The last line gives a error about not being able to resolve *=> on types int and dur. I wonder if this is correct behaviour; I can imagine many cases where a integer multiple of some duration is needed to avoid "trainwrecking" (a DJ term for two concurent tracks running at slightly different speeds). While we can obviously express integers as floats as well there may be cases where the int data-type can make guaranteeing we are dealing with a natural number easier, for example Std.rand2( ). while correct I don't think either alternative looks especially nice; Std.rand2(1,4) * 1.0 *=> foo; Std.rand2(1,4) $ float *=> foo; This does work in the comparable case of; //correct but not as ChucKian foo * 3 => foo; or even; 1.2 => float bar; //implicit casting in *=> does work here 3 *=> bar; So; I'd like to sugest a implicit casting of int to float or further overloading *=> in these cases. Yours, Kas.

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Fun ChucK Game for Nerds Like Us
by inventor-66＠comcast.net 20 Sep '08

20 Sep '08

Memorandum To: All ChucKists From: Inventor Re: HSTechSpy ChucK Game Greetings fellow ChucKists. You will be pleased to learn that I have endeavored to create one more way to waste your time on ChucKian adventures. I have developed a new game (last year actually) and recently added a healthy dose of ChucK content to it. In the game you are a Hardware / Software Tech Spy and you receive various Mission Briefings which you may or may not chose to perform. So far the first five missions have been software only and primarily based on the Perl programming language, but now I have added a 6th mission which is hardware based and involves a little ChucKing around. Rather than blog on endlessly as I often do in forum and list posts, I'll just give you the link and invite to explore the page: http://www.freedomodds.com/hstechspy/ If you visit, be sure to scroll down and check out Mission 6: USB Hardware Interface, which is the latest and most interesting ChucK mission. HSTechSpy is fun, it's silly, it's educational, and it's a great way to waste some time so stop on by and give it a read. Forever creating useless ways to spend your time with ChucK, I welcome you to join me on the neverending journey to nowhere. Enjoy. Les (Inventor)

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ChucK Humor (or the lack thereof)
by inventor-66＠comcast.net 19 Sep '08

19 Sep '08

How many ChucKists does it take to change a light bulb? Four. One to make a feature request, one to develop a custom light bulb interface that works great but is so complex that nobody else will ever use it, one to imagine a future in which ChucK can change it's own light bulbs, and one to hold the light bulb up while the world revolves around ChucK. How do you annoy a group of ChucKists? Ask them how to do file I/O in ChucK. Mention garbage collection just one more time... Joke about their excessive CPU consumption. Tell them that Csound is more powerful than ChucK. Ask them if ChucK can take advantage of multiple processors. If ChucK were an automobile, what kind of automobile would ChucK be? 1. A Corvette because it's built for performance but it's always in the shop. 2. A 1967 VW beetle because it's cute and everybody loves it. 3. A Corvair because it is "unsafe at any speed". Why did the ChucKist cross the road? 1. Because the other four ChucKists were busy changing a light bulb. 2. Because he was livecoding and wasn't paying attention to where he was going. 3. Because the CPU is always faster on the other side.

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Detecting when child shred has finished
by Paul Reiners 19 Sep '08

19 Sep '08

Is it possible to determine when a child shred has finished executing if you have a reference to the child shred? For example, in this code: // define function go() fun void go() { // insert code } // spork another, store reference to new shred in offspring spork ~ go() => Shred @ offspring; Is it possible to determine when offspring is done executing?

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