Comment by corethree
2 years ago
An alternative viewpoint on software:
https://www4.di.uminho.pt/~jno/ps/pdbc.pdf
Rather then using blurry fuzzy concepts about software. This book is called "Program design by calculation".
Which is to view software through the theoretical lens of math, science and engineering rather then "philosophy".
Should software design be interpreted using the blurry and hand wavy concepts of philosophy and literature? or should it be theoretically laid out completely with all primitives formally specified like newtons laws of motion? Can we model software in a very formal way and come to make EXACT statements and conclusions about program design rather then a bunch of opinionated takes?
Unfortunately, like all hard sciences pdbc is much harder to understand then a "philosophy" so most people end up switching majors to philosophy.
Or Perhaps it's not about the challenge... you just prefer the philosophical approach over the theoretical one. Your preference is very valid.
But to you I would ask: can you build a bridge, a car, or an airliner with philosophy? Or do you need hard formal theory and sciences? If we don't have hard and formal theory about software design are we being limited in what we can build?
Do the business requirements (fundamental assumptions around design to be more generic) of a bridge, car or airliner change dramatically over time?
I'd argue not.
Software design, in my opinion, is both a science and an art so my stance is that we need both the formal theory and science as well as the philosophy and that they shouldn't be viewed as mutually exclusive.
>Software design, in my opinion, is both a science and an art so my stance is that we need both the formal theory and science as well as the philosophy and that they shouldn't be viewed as mutually exclusive.
What formal theory have you ever used for designing your software? I would argue you've never used anything. Every abstraction you've ever made was likely a gut feeling, an instinct or following some vague hand wavy rule of thumb.
At best we use type theory for type correctness and complexity theory to calculate efficiency. That's basically as far as it goes with "theory" and these two things aren't even about "software design".
Software design in practice as most engineers use it today is, practically speaking (key phrase), 100% art. Sometimes people come up with big fancy words like "dependency injection" or stupid Acronyms like SOLID to create the illusion of formal theory, but these things are nothing of the sort. It's just tips and tricks.
The plane, the car, the bridge? Those things use both design and formal theory... software design as most engineers use it, again, does not use ANY formal theory, it's almost just purely design all the way down.
Aren't you being overly optimistic about the engineering disciplines' ability to compute things? How does engineering work: do you sit down with a spec (say, "create a wing that can lift a passenger plane"), and then run some formulas, and end up with a wing? Or do you propose a wing, based on past experience (rough shape and size), and _then_ bring in computation to make sure it provides the correct amount of lift, iterating through designs as you go?
Because I think it's really the last one. There is no formula to design a bridge: you design the bridge, and then use formulas and lookup tables to validate it is strong enough. Same for pretty much anything else produced by any engineering discipline.
So in that sense, engineering and programming aren't all that far apart: both start from past experience, and use various validation methods after a design has been proposed, iterating through designs to reach an optimal state. Software engineering, being a younger discipline, is still working on validation methods, and many practitioners find they simply have no budget to apply them (nor any life-or-death constraints that force them to). That's ok though. If you design a new can opener you aren't going through all the processes that apply to an airliner either.
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Just because it doesn't use formal theory now --- does not mean it/we shouldn't use it. I'm talking about needs, not haves.
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Mathematics and science can both be viewed as very fleshed out and practical branches philosophy, so they certainly aren't mutually exclusive.
Everything on the face of the earth falls under philosophy. It's the biggest non-category ever.
I'm basically talking about "philosophy" the way the book uses the word. Which in short is just the authors opinionated take on software masquerading as something a bit more "official" then just an opinion. I mean would you call your own opinions on software design a "philosophy"?
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You seem to think that this is some sort of battle between the wordcels and the shape rotators or whatever, it's not. Extremely smart people have been in these fields for thousands of years and they didn't think that math and philosophy are opposites or in some tension. Even a cursory familiarity with the history of math and philo will reveal this.
>Extremely smart people have been in these fields for thousands of years and they didn't think that math and philosophy are opposites or in some tension. Even a cursory familiarity with the history of math and philo will reveal this.
Yeah it was actually progress when the field largely separated the philosophical mumbo jumbo away from the pure math. In the past math text books were littered with this mumbo jumbo because people couldn't separate the philosophy away from the axiomatic logic. Textbooks were just a mess. Nowadays there's a clear delineation. I believe it was Newton who started this separation trend with his laws of motion.
Mathematics is an entirely separate department that is NOT under philosophy in most schools because of this.
I studied philosophy at a department with an analytic slant. So essentially with philosophers who have a hardon for math and science. Still, even there people were not talking nonsense like this.
Pure math is really nice, but there are so many aspects of human activity where this math is just totally useless. This is where we have to use the fuzzy words and stuff and where rigorous interpretation that you get trained in philosophy and other wordcel departments comes useful.
I really encourage you to engage with some history of philosophy. You'll probably enjoy it and maybe change some of your views. Maybe try some history of science?
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Calculate ease-of-use of a GUI. Yes, you can, to some degree. You also can't, to some other degrees.
Calculate correctness of some business logic, when part of "correctness" is correspondence to some badly-written procedures, and another part is correspondence to some regulations that are spread across ten thousand pages.
Calculate correctness of an OS scheduling algorithm that has to work against a (not precisely known) variety of task mixes.
And so on. There are parts of the requirements that are blurry and hand-wavy. That makes the "calculation" approach hard. At least, you have to translate the hand-wavy stuff into precise things that you can calculate. And you can't calculate that translation process, because the inputs are hand-wavy.
Given a formal specification the idea is that a theory should be in place to calculate the design. We don't fully have this yet.
Given a hand wavy blurry specification, well... of course the implementation will be blurry and hand wavy as well.
Well... given a hand wavy blurry specification, you can create a formal specification - just not by formal means.
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That book has its very own philosophy, in particular that "pointfree" (pointless?) programming is a good thing. No, it isn't.
You think it's not good because that's just your particular philosophy.
Pointfree programming allows for theory. It allows for algebraic composition of functions which in turn allows application of algebraic theory.
I mean in the end what is a computer program? A set of functions. Wouldn't you build a program by composing functions together to form bigger functions? It makes sense for this to be the fundamental theory of program organization.
Of course IO and mutation aren't initially included in this theory but that's a different aspect of the theory once you get more advanced.
So basically you're just saying something along the lines that in your opinion you don't like the theory of algebra or geometry or some such. It's not invalid, but like the philosophy book, just another opinionated take.
There is nothing wrong with functions. But forcing yourself to think exclusively in functions doesn't make much sense, and that is what pointfree is all about. It's basically a fetish. After all, functions have a domain, and the domain consists of objects that are often not functions.
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