@whale-av What object numbers are wrong for you? They are all correct for me, only thing wrong that I see is an outlet number, it tries to connect the [print] to the non-existent outlet 2. All you need to do to fix it is change the [loadbang] into an [initbang] and then remove the [delay] and [pipe]s, the [delay] causes the iolets to be created after the initialization phase and after the load phase as well most likely. Same issue, just with a few extra quirks thrown in.
matrix~.pd
I also replaced the [metro 1]s with [until]s, we no longer need all those tricks. The [print] still does not connect, I am not sure what that is supposed to connect to, guessing there is an outlet #2 being created somewhere in the patch that I did not see? Guessing this also makes it not work with extended.

@whale-av said:

but strangely

You are experiencing the same issue as @FFW and using [initbang] for the iolet creation will solve it. I believe your method will only work with extended but it might also work with very old versions of vanilla.

@FFW Loadbangs happen after the patch is fully loaded, so after all connections have been made/attempted to be made between all the objects/abstractions in the patch, so those dynamically created iolets don't exist yet and the connections fail. Replacing the [loadbang] with [iemguts/initbang] will cause the iolets to be created when the abstraction is loaded but before it has been connected to the other objects in the patch so you connections to those iolets will not fail.

@vamoscreciendo I believe the encoders on the mpd226 are relative? If so, you can use those free pads to switch what parameter they control with my cc abstraction in https://forum.pdpatchrepo.info/topic/13385/midi-rotary-encoders-values-get-confused/2 This will let you control a great number of parameters with just your 4 encoders, as many as you want to switch between. It works with sliders and nbx.

@ddw_music said:

at the same time, I'm a bit bewildered why so many things I've tried to say in this thread seem to have gotten a "well, no, that's not it" where I guess I hoped for a "hmm, that's interesting, have you considered?"

Forgot to address this. It was the stack confusion, your thinking that I meant there was no stack made your posts come across as non-sequitur and saying I am wrong while not explaining why, just explaining your logic in increasingly condescending ways which made it seem like you completely misunderstood what I said and were stubbornly just saying "I am right." I probably came off the same to you. But that was not the case, we were just having different discussions and not realizing it. Hopefully my previous post where I tried to make no assumptions about anything and use it towards both our views will clear things up so we can get back on track?

I suspect we also have abit of a personality clash and take things from each other slightly askew from what we intended, generally not much of an issue and we just move on.

Edit: and you understood that despite my forgetting it in the previous post

@ddw_music

grep " goto " pd-0.55-1/src/* | wc -l
283

There might be one or two comments in there but those are predominately literal gotos. Goto being discouraged is a holdover from BASIC which originally only had goto for moving about in code, it had no functions and literally executed code line by line, as BASIC developed and got other ways to control execution they discouraged the use of goto. In any language with functions or objects etc there is no need to discourage the use of goto since no one is going to try and control program execution through goto for any reason other than an academic exercise. A goto is just telling the IP to goto a remote place in the program code instead of the next instruction, happens everytime you run a function. The most basic implementation of a function:

function f (a b) {  -- push current address to return stack, pop a and b from data stack, set a and b, goto f
    c = $a+$b -- execute f
    return $c -- push c to data stack, pop address off return stack and goto it
}

Generally stacks only hold one data type so we would also have to set the return type in the function header function int f (a b) so return knows which stack to push to. Higher level languages just do all this stuff for you. In pd it would be the outlets which are the gotos, outlets are structs which hold pointers to tell pd where to goto next. Possibly the pointers in the outlet struct might just be used for telling the GUI how to draw the wires, depends on how it is implemented and I can think of at least a half a dozen different ways it could be implemented to the same ends. If the stack only holds pointers to objects it is easy for pd to function without a return stack, when it hits a branch it pushes the pointer for the branch, goes down the branch pushing the pointer for each object, pops each to execute (possibly each being another goto) finally popping the return and does the goto to the branch point to do the next branch. The object way I outlined above accomplishes the same thing but I believe it would be a bit more efficient, in that case the stack could be a data stack or a pointer stack which also holds pointers to data.

Back when I was last trying to sort this out I ended up digging into [trace], it actually has its own stack (possibly two, did not deeply analyze it since it was not what I was looking for). When you turn tracing on it enables tracing in EVERY object on the canvas and they all send their messages back to [trace] which puts them on its stack. This is why enabling trace slows down message passing, also why it took so long for [trace] to get implemented, not so simple as just printing what is on the stack. I think the second stack in [trace] might be a pointer to the pd stack and it uses pd's stack to determine which messages to print and maybe gets part of its data from the stack but as I said, I did not dig into it too deeply and that was awhile back. I suspect pd's stack is a pointer stack but I am not sure if it only holds pointers to objects or also pointers to data, if the latter single stack returns could be more troublesome.

there are a few legit ways to use them, but otherwise, don't; same for gotos.

In my experience they are generally used for blocks of code which you need to reuse often but do not work well within the context of a function or the like, would need to be broken up into dozens of small functions which would make the code difficult to read and inefficient to run because functions have good deal of overhead and generally have scope and limited in what they can return. Gotos also have the advantage of being able to return to somewhere other than from where they were called from, which can also help makes things more efficient, depends on the language and how things are implemented. In some languages goto is slightly different in different contexts, in a loop it is the same as break and goto and in a function it is return and goto, etc.

@ddw_music I never said pd did not have a stack, I said that I did not think it had a RETURN stack. I don't think I can reasonably respond to your post without risking more confusion.

@FFW I sort of thought you meant something like that but wasn't sure. I don't think message rate stuff is flattened and can't find anything in the source but I don't really know, I just don't see much advantage in doing it with how slow and simple message rate is. Thanks for the clarification.

@FFW said:

By the way, it's also the order the process stack is filled because the full tree is flatten before it computes

Is there a process stack? Can you tell me where to look in the source for it? What is actually on this stack? Is my above reasoning regarding the patch just being a chain of objects incorrect? The patch being a chain of C objects explains why we can't turn off message rate and what happens when pd is running out of cpu but I have not quite grasped how pd's scheduler actually works. I'm guessing my previous post is difficult for a non-native English speaker since my grasp is not great and my explanation is probably not the clearest and I am not sure how well you know pd's internals either. I am almost at the point where I will post on the mailing list to get a response from the devs but I want to get enough of it that my post is not just a very verbose way of saying "I don't get this, explain the entire inner workings of pd for me!"

@ddw_music All that stuff about instruction pointers and the like was me getting turned around and falling back onto Fourth because that is where my mind goes when I think about stacks. In pd there is no instruction pointer so never any need to return or backtrack or goto. In pd's core, every internal and external object is a literal OOP object and the inlets and outlets are methods of that object. When we create a new object pd creates a new C object of that type and makes an entry for it in glist with its pointer and UI details; when we connect a wire to its outlet pd retrieves the pointers to those objects from the glist and then goes through the outlet method. I am not quite sure how it deals with reaching the end of the branch, I suspect that the last object always has its outlet method run to point it at the branch point and when we append a new object pd just passes that to the new object when it updates the previous end of chain object's outlet method to be the new object.

Some details there might be a tad off, I am not quite good enough with C pointers to really follow pd's source yet, but I am fairly sure that is the mechanics of it. I have no idea about how Max handles this stuff but I would assume it is quite similar.

@ddw_music said:

In Pd, wires are procedure calls, not gotos.

Are they actually procedures or just conceptually? I would assume the latter but if they actually are procedures can you point me where to look in the source? I get the depth first stuff, I just turned myself around in those edits, hence the follow up post and the disclaimer added to the original post. I did a bit of digging in the source and I think my original point was correct, pd does not do anything weird with how it uses the stack, it is just that without a return stack we can't actually return which means we have to go about/think about things in a different way.

lisp would write (print (* (random 20) 2)) where the last operation to be performed ("print") is at the head of the tree

But there is no tree in lisp, right? it is just a list data structure for the REPL to evaluate. I can't quite grasp how lisp works under the hood, I poisoned my brain with one of those build your own lisp tutorials which I later learned did not actually function in anyway like lisp proper, it was just an easy way to do a lisp like language and I have been lost ever since. Lisp is one of the languages I really want to learn and understand because it is supposedly great for building languages but there is something about it which I fail to grasp.

Regarding Forth since you keep bringing it up, it is no where near as mind bending as people think, in practice you don't spend much time doing that low level RPN stuff; you define some words and use those words to define other words and before you know it you have a purpose built high level DSL for your task. But you have to learn all that low level RPN pushing and popping stuff first. I am a big fan of Forth and what got me interested in language design/implementation was the whim of implementing a language in pd, so I found a language which would seem suitable for that whim and it was Forth, I learned Forth by implementing it in pd.

I guess I went off on a tangent there, went into implementation and lost focus. The important thing there is that abstractions are not functions which you return from or objects you point to, they are macros which expand in place. We can sort of use them like objects or functions but they are macros from the users perspective and that is what we need to keep in mind.

Probably best to skip this post and just read the next, will leave it here since it could result in useful replies from those who understand the internals of pd and perhaps some people here are as interested in these sorts of details as I am,

@ddw_music I think pd uses the stack in exactly the same way but the difference here is that pd lacks a return stack (and stack/instruction pointer manipulation); abstractions are actually macros which are expanded, they are not functions which are pointed to and returned from. The unique ID given to an abstraction when it is expanded allows us to use them sort of like functions and mimic scope but pd is a very simple globally scoped imperative language.

Edit: I guess pd does have very basic IP manipulation, [send] is essentially a goto. The big difference with pd and dataflow is that the IP carries a bit of our data with it as it moves through the patch. The result of an operation does not go onto the stack but is carried with the IP. Or maybe data is only carried with the IP in a conceptual sense and result actually is TOS? Think I will have to investigate pd's stack when I have the time.

Edit2: I guess wires are also gotos then. I suppose what this really is is that pd is a 2d language, [send] and wires only seem like gotos if we try and think of pd as a 1d text language.

Edit3: (last one) Pd would have a return stack, but the returns always point to branches. A [t b b b b] is essentially push and drop commands for the return stack, rightmost bang pushes, leftmost drops. End of the branch having an explicit pop so it can return to the [trigger] or where ever the code branched. More like other languages than I thought in stacks, assuming my reasoning is sound, the big difference being that pd has no concept of anything remotely function like. IP probably carries the pointer as well as the data, would save popping everytime it return which means no return stack and back to my original point of pd lacking a return stack (subrosa edit4.) But that would mean the IP caries a return stack in a rather funge like way, which it might, the return stack is part of the IP object and not the interpreter proper (subrosa edit5.)

@ddw_music said:

"Return to caller" as in any structured or object-oriented language is nicer

I think this thread may have convinced me that the idea of return to caller is antithetical to dataflow, it goes against the flow of data and my solution which you said side stepped it is just restating the problem into dataflow. Not that this was my intent, didn't even realize I sidestepped it until you mentioned it but it got me thinking. Not sure if it is even possible or practical to avoid but I think I am going to try and be more rigid with the flow of data for awhile and see what happens.

Here, I'm referring specifically to

That is what I originally thought but the previous post confused me, I now realize that you weren't addressing my patch directly but offering a summation of what you got from the thread in your reply to me.

whereas most other solutions posted here seem to assume it will always be a single float):

Just replace [array] with [text] and make a tiny change in stream.pd/add other abstractions asStream can load/change the arguments it is loaded with. I switched from [text] to [array] because you used an array in your SC example and I switched tactics to confront your example head on. Originally I thought your ignoring the suggestion of [value] was that you wanted to use things other than floats and then thought that what you were having issues with is the methodology. This is probably a part of the problem porres mentioned about people having issues transitioning to pd from another language, you have a good grasp on programming and when you ignore a solution which seems the easy/obvious solution to us it is easy to assume you have a good reason for ignoring it. These sorts of assumptions are probably reasonably common in such situations, we all gave up on the suggestion of [value] early on and it came back into the discussion purely on accident.

It has been an interesting thread, the failures in communication ended up surprisingly insightful on many fronts.

@porres I am more than happy to answer any questions you have about using it or how it works. As I said in the other thread, I hate doing documentation, it tends to turn into a rabbit hole for me and eat up a good deal of time; once I start thinking about usage I start seeing how some things are not right in the abstraction and I start fiddling which means a change to the docs and it quickly turns into a feedback loop. That small change to the manual I suggested in the other thread caused/required me to reread much of section 2 and reread a few sections many times even though I had it all typed out after reading two short section once.

I don't think extending pd would solve this issue, the question was not really how to do this in an isolated situation but about the methodology. How do you do something like functionA (functionB (1 2) 849 functionC ($1 $2) asdf) in pd? In a one off situation it is generally a fairly simple problem to solve but to make it so at anytime you can do the equivalent of [abstractionA [abstractionB 1 2] 849 [abstractionC $1 $2] asdf] is a much more complicated issue and one which externals don't solve and often make it seem more complicated than it actually is because they have a tendency to make pd feel like a higher level language than it is, keep the user from ever really learning the nuances and techniques of the low level dataflow paradigm that is pd. The one off solutions which often come up in these threads result in what I think @ddw_music refers to as "spray everywhere," to try and build that solution into every abstraction so you can use it everywhere but to get the equivalent of abstractions calling abstractions would require you to fill your abstractions with [v ]s and [send]s and [receives]s in the vain attempt to cover every possible situation and very complicated/convoluted bit of inter abstraction communication. All my posts since the first asStream screenshot post have been about methodology, how to build higher level paradigms in a low level language like pd and avoid spraying everywhere, this is what asStream is meant to show. Like any well founded low level language pd is quite good about giving you the tools to build out higher level functionality and adapt it into your own language. At least that is what I got from this thread.

asStream has the potential to be a really useful abstraction but still has some issues, I can help you understand it and flesh it out, just ask your questions, they will probably make it a better abstraction than either of us could make on our own. As an exercise I will attempt to repatch it in your heavily subdivided patching style on my next break from my projects, I will probably fail but it will be interesting, I get the logic of the style but it obfuscates the dataflow for me and anytime I want to understand the work of a subdivider I have to remove all that subdivision, I can't even see how it could be subdivided into discrete, well named subpatches of highly singular/specialized function, for me it already is that.

@porres No help file, usage notes in asStream.pd, this thread is the documentation. If I ever get it to the point where I don't think there will be any major changes I will upload it with help files over in Abstractions. But a new version, reworked it as an array object since that is what it really is. Also added looping. Still needs lots of work to be a useful abstraction for more than learning from, it is kind of fun though and eventually I will develop it more.

asStream.pd
stream.pd

@ddw_music said:

Though this means that your approach could be used only in self-timed situations,

Just need to change [obj 10 10 stream $1 $2 $3...( to [obj 10 10 $1 $2 $3...( and add in some simple logic and now asStream can load the abstraction you specify through methods/arguments. As I said earlier, you design the interface and the protocol which is what those sends and receives and values and dollar arguments in asStream are, an interface and protocol for communicating with the stream.pd abstraction or any other abstraction designed to work with that interface. Object names themselves can also be filled in through arguments, [$1 $2] can be either a metro or a receive or anything else but [$1 $2 ....] are actually [list]s so they only give you two inlets and one outlet, if you need more than that you need to resort to editing the abstraction in a text editor, patch it together with any object with suitable io and then open it in a text editor and edit that object into $1 $2... And there is plain old dynamic patching to programmatically create the required patch. Lots of option and they can all be mixed.

Realized my errors finally, extra output was because I forgot to add a [- 1] after a [list length]. The [v ] not resetting was order of operations but decided that the logic of automatically resetting to zero was flawed so now it resets only if you send [start( when it is at the end up the array. The stupidest mistakes are always the hardest to see. Fixed and added an optional delay before the metro so they don't have to all start at the same time. Fixed [append( as well and give it a right inlet for appending without the [append list( which is probably how it should be? Still could use some logic to make sure you don't duplicate streams and perhaps the ability to configure individual streams but that is for someone else or some other day. Added some usage notes in the patch.

Improved version below.

@ddw_music Value has been mentioned multiple times in both threads It has been fun. I took a break from my projects and threw together asStream, it will be awhile before I get back around to it but here it 99% complete, there is a stupid error on the append so it is actually insert and for some reason I just can not figure out it is not resetting the [v] when it completes. You can solve those if you care. Oh, and it spits out an extra repeated number second to last, at least with my simple test, not sure why but worst case a [change] between the [array get] and [s] in stream.pd will fix that. Report back if you figure out why it is not resetting to zero, driving me nuts but I have other things to do. Patch in next post.

Not sure what you mean by "spray everywhere," these are targeted approaches and there is no copying. Does reallocate on resizing the array but that could be avoided easily enough, just use an array bigger than you will ever need and only use what you need.

@ddw_music said:

The latter is what I'm after

Oh, that is simple enough to do, just replace the [f ] in the stream abstraction with a [v ] shared between the abstractions like the array. Getting there?

Obviously you would want asStream to create the [array define]s as needed and the symbols for the array and value having their own iterators so it can manage multiple streams but that is simple enough. Oh, and register its array and value symbols so you can grab them as needed and append to the array and what not.

@ddw_music said:

Seems to me English is not up to the challenge here.

We just needed to identify the actual issue here, which is not patching but low level language. To do the sorts of things you want to do means you have to define an interface and a protocol, those things which high level languages like SC take care of for you. Pd has no concept of an instrument and if you want to use such a paradigm it is up to you to implement it. One way would be to send the instruments args to a master abstraction which then takes the necessary actions, a quick and simple example which is not fully fleshed out but should show the logic:

Started adding in my $0s halfway through. You would probably want a [text] in [register] to keep track of all this stuff and it can also keep track of values you can query for in the various abstractions and what not through their send methods. [stream] would need some more logic, needs a [receive] to start/stop it and probably would want a way to change its settings as well as an [iemguts/canvasdelete] so you can clean things up as your patch changes. [synth1] seems pretty complete and a solid instrument, I wouldn't change it.