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

Passing classes to functions
by Adam Tindale 04 Oct '09

04 Oct '09

Hi All, I was doing some work and created some bugs that I ironed out when I discovered something: when non-primitive types are passed to functions they are passed by reference and not by value! I include a test so you can see what I mean. I hope somebody find this useful. --art class test{ 0 => int val; } test obj1; // obj2 is a reference to obj1 test obj2 @=> obj1; <<< obj1.val , "original object">>>; <<< obj2.val , "reference to original">>>; 2 => obj2.val; <<< obj1.val , "original object">>>; <<< obj2.val , "reference to original">>>; fun void testclasspassing(test i) { <<< i.val, "in function" >>>; } testclasspassing(obj1); testclasspassing(obj2);

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forward reference oddity
by Robert Poor 02 Oct '09

02 Oct '09

Here's another oddity. The following file: --------------------------------------- // file: ouroboros.ck class Ouro { Boros @ boros; fun void set_boros(Boros boros) { <<< this.toString(), "set_boros(", boros.toString(), ")" >>>; boros @=> this.boros; } } class Boros { Ouro @ ouro; fun void set_ouro(Ouro ouro) { <<< this.toString(), "set_ouro(", ouro.toString(), ")" >>>; ouro @=> this.ouro; } } --------------------------------------- gets a compile-time error: --------------------------------------- r% chuck ouroboros.ck [ouroboros.ck]:line(5): class 'Boros' has no member 'toString' [ouroboros.ck]: ...in function 'set_boros' --------------------------------------- This is odd, since (AFAIK) toString() is defined on the Object class, and all classes inherit from Object. If I remove the toString() call on boros as below, it compiles without error. Note chat ChucK has no problem compiling ouro.toString() in function 'set_ouro': --------------------------------------- // file: ouroboros.ck class Ouro { Boros @ boros; fun void set_boros(Boros boros) { <<< this.toString(), "set_boros(", boros, ")" >>>; boros @=> this.boros; } } class Boros { Ouro @ ouro; fun void set_ouro(Ouro ouro) { <<< this.toString(), "set_ouro(", ouro.toString(), ")" >>>; ouro @=> this.ouro; } } --------------------------------------- Is this because Boros is a forward reference? And is this not a bug? - Rob

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The ChucK Show on iTunes
by Les Hall 02 Oct '09

02 Oct '09

Fellow ChucKists, I have great news. Unless I'm mistaken, this news is so exciting I don't really believe it's true. Shane Morris of www.electro-music.com just told me that iTunes is going to list the internet radio station that airs The ChucK Show in it's (arguably huge) list of stations! Wow, I'm excited about this. I don't know what to think, other than I should just "Keep on ChucKin'". Tomorrow at 7pm EST will be "The Game Show" which will have a lot of ChucK music on it. It's sort of a cross between the classic shows "Name That Tune" and "The Gong Show". I will play a variety of music, all from electro-music.com members, and then people in the chatroom will try to guess the author, song name, software or hardware used to create the music, etc. Multiple points are awarded each song as people guess different stuff. And my friend Bill will mail out a CD to the winner. A good time is practically a guarantee, so tune in if you can. Again, I'm not quite sure if this is real but I think it is so if you'd like your ChucK music to appear on iTunes, send me mp3's or code. Actually send both! mp3's are better if you use much CPU at all because all I have a little 5 year old eMac and it's busy running the show controller as well. See you on the radio, Les For those about to ChucK, we salute you! - Ge Wang

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class abuse
by Robert Poor 01 Oct '09

01 Oct '09

I can hardly call this a bug, since people who go around casting classes get what they deserve, but it's unexpected behavior nonetheless. Consider the following -- the salient point is that General is a super class, Specific extends General. =================== class General { fun void announce() { <<< "I am general:", this.toString() >>>; } } class Specific extends General { fun void announce() { <<< "I am specific:", this.toString() >>>; } } fun General create(int type) { // factory method return (type==0)?(new General):((new Specific) $ General); } fun void process(General obj) { <<< "processing general object:", obj.toString() >>>; } fun void process(Specific obj) { <<< "processing specific object:", obj.toString() >>>; } General @ obj; create(0) @=> obj; // [1] create a General object obj.announce(); // [2] calls General.announce() process(obj); // [3] calls process(General obj) create(1) @=> obj; // [4] create a Specific object obj.announce(); // [5] calls Specific.announce() process(obj); // [6] calls process(General obj) process(obj $ Specific); // [7] calls process(General obj) =================== which produces the following (I've annotated the line numbers): =================== r% chuck classtest.ck [2] I am general: General:5df960 [3] processing general object: General:5df960 [5] I am specific: Specific:5de400 [6] processing general object: Specific:5de400 [7] processing general object: Specific:5de400 =================== Lines [1], [2], [3] do what you expect: creates a general object, calls the General.announce() method, and calls the process() function which has the <General obj> signature. So far so good. Lines [4], [5] also do what's expected: creates a Specific object and calls the Specific.announce() method. Line [6] is up for grabs. I half expected it to call the version of process() with the <Specific obj> signature (since it called the Specific.announce() method at step [5]). On the other hand, obj was declared as a General class, so it doesn't surprise me that it called the version of process() with the <General obj> signature. Line [7] is what bugs me: obj is cast to the Specific class, and the ChucK compiler _knows_ this at compile time. Yet it calls the process(General obj) function, NOT the process(Specific obj) function. If ChucK uses run-time checking for signature discrimination, then [6] should call process(Specific obj). But it uses compile time checking, right? So why doesn't it call process(Specific obj) in step [7]? I promise not to lose too much sleep over this. If someone familiar with ChucK's type system wants to report this as a bug, be my guest. I'm just happy to find that ChucK has a smidgen of run-time type discrimination (as evidenced at [5]). - Rob

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watchdog activate!
by Andrew C. Smith 01 Oct '09

01 Oct '09

[chuck]:(3:SEVERE): real-time watchdog counter-measure activating... What does that mean? How can I fix it? The shell/--loop prints it (and then stops working) fairly often, usually when I hit lots of notes really fast. Andrew

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object / class hacking
by Robert Poor 01 Oct '09

01 Oct '09

Chucksters: Three questions in one message (generally a bad idea, but they're short): [1] Accessing class name from an object I seem to recall seeing a way to get an object to yield its class name, if only for printing. But I haven't been able to locate the e- mail thread where that was discussed. Was I hallucinating? (I really only want this for debugging, but if it's a supported function, it may be useful for dispatching on class type.) [2] initializing an object Is there a subclassable method that is called when you instantiate an object? or do have to instantiate then initialize manually, as in: public class Foo { Controller @ c; fun void init(Controller c) { c @=> this.c } } Foo foo; foo.init(x); [3] "natural" sorting of objects Is there any attribute of an object that you can reliably use as a sort key? I ask because I want to speed up searching of an array of objects (e.g. to see if an object is already present). As I understand it, I can't use a hash array since there are no iterators. I guess the question should be: what's the fastest way to maintain a *set* of objects (i.e. a collection in which an object may only appear once) with the usual operations for insertion, deletion and iteration? TIA. - rob

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new versions?
by Fernando Lopez-Lezcano 01 Oct '09

01 Oct '09

I realize that no new big things may have changed at the source level that would trigger a new release of chuck and, say, miniaudicle. But. Isn't it time to do it anyway? Anyone downloading and trying to compile either package from source in a modern up to date linux distro will find that the software does not build. Not a good first time experience. Chuck should move with the times, including patching it for stricter (current) gcc releases, etc, etc. IMHO, of course. -- Fernando

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Re: [chuck-users] implementing a set (was object / class hacking)
by Robert Poor 30 Sep '09

30 Sep '09

Hans: To simultaneously stand my ground and display my ignorance: I've written several flavors of hash tables in my life, but I'm not sure how the Stroustrup code sample helps in this case. If you are suggesting that I hack the Chuck source code, you should know that I do entertain such ideas from time to time, but I usually come back to my senses within 25::samp -- it's just not on my list of priorities. A "written entirely in ChucK" solution -- albeit non-optimal in execution speed -- is good enough for my needs. I'm more into optimizing my days than my milliseconds. Thanks, though. - Rob On 30 Sep 2009, at 14:01, Hans Aberg wrote: > On 30 Sep 2009, at 22:12, Robert Poor wrote: > >> To clarify: I'd like to implement a set for storing a collection of >> homogenous objects. Specifically, I need to be able to test for >> the presence of an object in the set, add an object to the set (if >> not already present), delete a object from the set, and iterate >> over all the objects in the set. This last requirements, sadly, >> eliminates Chuck's "associative arrays". >> >> It's worth pointing out that: >> >> arbitraryobject.toString() >> >> will generate a string of the form "ClassName:hexLocation". >> Assuming that Chuck NEVER (ever) relocates a live object in memory >> (Chuck has a reference counting GC, not a copying GC, true?), that >> string could be useful as a unique ID. But Chuck lacks the string >> operations to reduce a string into a hash key. > > Bjarne Stroustrup, "The C++ Programming Language", 3.1.3, has a > simple hash function: > name* look(const char* p, int ins=0); > name* insert(const char* s) { look(s, 1); } > > struct name { > char* string; > name* next; > double value; > } > > const TBLSZ = 23; > name* table[TBLSZ]; > > name* look(const char* p, int ins=0) { > int ii = 0; > const char* pp = p; > while (*pp) ii = ii<<1 ^ *pp++; // Hash function using eor: ii<<1; > ii ^= *pp++; > > if (ii < 0) ii = -ii; // Reduce to array range. > ii %= TBLSZ; > > for (name* n = table[ii]; n; n = n->next) // Search > if (strcmp(p, n->string) == 0) return n; > > if (ins == 0) error("name not found"); > > name* nn = new name; // Insert > nn->string = new char[strlen(p) + 1]; > strcpy(nn->string, p); > nn->value = 1; > nn->next = table[ii]; > table[ii] = nn; > return nn; > } > > Hans

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[ot] Technical Director and Audio Specialist positions at Princeton
by dan trueman 30 Sep '09

30 Sep '09

apologies for the off-topic posting, but i thought this might get the word it to a bunch of the right people; please share this with anyone or any lists you think appropriate, and direct questions my way. thanks!! dan Technical Director The Music Department at Princeton University is seeking a Technical Director of Electronic and Computer Music Studios and The Princeton Laptop Orchestra (PLOrk). The position provides technical facilities management support for the Music Department. The selected candidate will provide instruction and consultation on the use of facilities and on music technology in general, and will provide other services as needed for Music Department faculty and students. The Technical Director will analyze department technology needs; direct the purchase and maintenance of equipment to fill these needs; and design, install and maintain the Music Department’s electronic music studios. Additional duties include working with students and faculty on the design and implementation of experimental systems and interfacing with the Princeton University Office of Information Technology. The Technical Director performs production work for faculty recording projects, including editing, mixing, and mastering. He or she also serves as Assistant Director of the Princeton Laptop Orchestra (PLOrk) which includes the redesign, development and maintenance of PLOrk technologies, assistance in the instruction of core electronic and computer music courses, and creative contribution to, participation in, and support of, PLOrk performances both on and off-campus. Education required: Bachelor’s degree Essential qualifications: One to three years of direct or related experience, experience with contemporary audio software and hardware, and a working knowledge of music literature and musical style characteristics. Note: Five months of the year this position has a demanding work schedule and the successful candidate must be able to work evenings and weekends as needed. Preferred qualifications: Hardware and software RAID arrays, extensive experience in hardware maintenance and repair, data recovery and disposal software and strategies (ex: Boot n’ Nuke), diagnostic software and strategies (ex: SMART, PC-Doctor), security software and strategies (ex: Symantec Antivirus), Max/MSP, Supercollider, ChucK, basic practical electronics knowledge and skills, Protools and Final Cut Studio, Peak Pro, Digital Performer, Logic Studio, and audio software development skills. Also desirable is experience in programming and electronics, although it is assumed that most candidates will learn new skills while in the position. Graduate work in electronic/computer music and/or music composition is desirable. Full-time salary minimum: $51,100. Note: this is a half-time position. Depending on the candidate’s interests and qualifications, this position and the Audio Specialist position have the option of being combined into a single, full-time position. To apply: Applicants should submit their curriculum vitae, a cover letter and a list of the names and addresses of three people who are willing to write on their behalf by November 1, 2009. Princeton University is an equal opportunity employer and complies with applicable EEO and affirmative action regulations. Please apply online at http://jobs.princeton.edu +++++++++++++++++++++++++++++++++++++++ Audio Specialist The Department of Music at Princeton University is seeking an Audio Specialist. The position provides professional-quality audio engineering services and technical facilities management support for the Music Department’s performances in Taplin Auditorium, other campus venues and off-campus if required. The selected candidate will oversee concert recording, sound reinforcement and other audio services for Music Department faculty and students. The Audio Specialist will analyze department recording and sound reinforcement technology needs and direct the purchase and maintenance of equipment to fill these needs. Additional duties include working with students and faculty on the design and implementation of experimental systems and supervising the student position of assistant audio specialist. The Technical Director performs production work for faculty recording projects, including editing, mixing, and mastering. Education Required: Bachelor’s degree Essential Qualifications: One to three years of experience in audio/ recording technology and sound reinforcement, experience with contemporary audio software and hardware, working knowledge of music literature and musical style characteristics, microphone use and recording techniques. Note: Five months of the year this position has a demanding work schedule and the successful candidate must be able to work evenings and weekends as required. Preferred Qualifications: Audio software development skills, ProTools and Final Cut Studio, Peak Pro, Digital Performer, Logic Studio, Sibelius, Finale, Tonmeister Technology trained. Salary minimum: $47,800 for full-time position. Note: this is a half- time position. Depending on the candidate’s interests and qualifications, this position and the Technical Director position have the option of being combined into a single, full-time position. To apply: Applicants should submit curriculum vitae, a cover letter and a list of the names and addresses of three people who are willing to write on their behalf by November 1, 2009. Princeton University is an equal opportunity employer and complies with applicable EEO and affirmative action regulations. Please apply online at http://jobs.princeton.edu or (less preferred option)—mail to: Search Committee, Attention: Marilyn Ham, Princeton University, Department of Music, 310 Woolworth Center, Princeton, NJ 08544.

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rate parameter for StkInstruments?
by Robert Poor 30 Sep '09

30 Sep '09

A subset of StkInstruments (BlowBotl, BlowHole, Bowed, Brass, Clarinet, Flute, Saxofony) take a "rate" parameter. Looking at the source code suggests that it's supposed to control the envelope rate, but I'm not convinced. Setting to values between .001 and 1000.0 doesn't appear to make any audible difference, at least for the few cases I've tried, as in: Saxofony sax => JCRev r => dac; .5 => r.gain; .05 => r.mix; [ 61, 66, 63, 68, 65 ] @=> int notes[]; while( true ) { 0.5 => sax.stiffness; 0.5 => sax.aperture; 0.5 => sax.noiseGain; 0.5 => sax.blowPosition; 6.0 => sax.vibratoFreq; 0.1 => sax.vibratoGain; 0.5 => sax.pressure; for (.01 => float rate; rate <= 10000.0; 10.0 *=> rate) { <<< "rate: ", rate >>>; rate => sax.rate; for( int i; i < notes.cap(); i++ ) { Std.mtof( -12 + notes[i] ) => sax.freq; 0.6 => sax.noteOn; 300::ms => now; 1.0 => sax.noteOff; 100::ms => now; } } } The code examples don't show it being used. Can anyone shed light on the .rate parameter? (I was hoping to make a Clarinet or Saxofony with a sharper attack time, but now I'm simply curious.) - Rob

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