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Hardware was for a very long time a limiting factor in the practicality of FP. For most general applications, today this is a relative non-issue. FP is also pa

by epgui 3y ago

Hardware was for a very long time a limiting factor in the practicality of FP. For most general applications, today this is a relative non-issue. FP is also particularly well suited for cloud computing and parallel computation.

charcircuit 3y ago
The parent comment was talking about aligning programming languages with the hardware. I am not commenting about the viablity of those languages, but rather that if your goal is to write the most performant code by understanding the strengths and weaknesses of the hardware than using fp concepts is not the way to do it.
- epgui 3y ago
  I feel like in both of your comments you've changed the topic slightly. I responded to the following comment, which I interpreted literally: > Very little innovation in programming languages has happened regarding new realities at the hardware level especially transition from serial to parallel execution
- AnimalMuppet 3y ago
  Well... if code were pure (in the FP sense), then a "sufficiently smart compiler" could move it around to extract the maximum performance. But, as always, the sufficiently smart compiler never shows up. So we're left with the humans doing the tuning, and as you say, FP is kind of antithetical to that approach.
  - Chris_Newton 3y ago
    But how will language performance evolve as the nature of the hardware our programs run on evolves? IMHO this is not an easy question to answer right now. C compilers don’t produce 100% optimal assembly language in all cases, but typically the assumptions they make are light. The executable code they output is somewhat predictable and often close enough to hand-optimised assembly in efficiency that we ignore the difference. But this whole approach to programming was originally designed for single-threaded execution on a CPU with a chunk of RAM for storage. What happens if we never find a way to get a single core to run much faster but processors come with ever more cores and introduce other new features for parallel execution? What happens if we evolve towards ever more distributed systems, but farming out big jobs to a set of specialised components in the cloud at a much lower level than we do today? What happens if systems start coming with other kinds of memory that have different characteristics to RAM as standard, from content-addressable memory we already have today to who-knows-what as quantum technology evolves? If we change the rules then maybe a different style of programming will end up being more efficient. It’s true that today’s functional programming languages that control mutation and other side effects usually don’t compile down to machine code as efficiently as a well-written C program can. The heavier runtimes to manage responsibilities like garbage collection and the reliance on purely functional data structures that we don’t yet know how to convert to efficient imperative code under the hood are bottlenecks. But on the other hand, those languages can make much stronger assumptions than a lower-level language like C in other ways, and maybe those assumptions will allow compilers to safely allocate different behaviour to new hardware in ways that weren’t possible before, and maybe dividing a big job into 500 quantum foobar jobs that each run half as fast as a single-threaded foobaz job still ends up doing the job 200x faster overall.
    - kaba0 3y ago
      > C compilers don’t produce 100% optimal assembly language in all cases, but typically the assumptions they make are light. The executable code they output is somewhat predictable Lol, since when? C compilers literally will run some of your code at build time, and only write the results into the binary and they do all sort of crazy "mental gymnastics" to make people believe it is still a dumb single-pass compiler.
sidlls 3y ago
"FP" camps tend to come in two flavors: "I'm a mathematician writing a computer program, and all problems will be made to look like math problems even if it means the program becomes an inscrutable mess of types and dense syntax" and "functional-ish idioms are included". The latter is useful, sometimes, for cloud computing and parallel computation; the former tends to have too many problems (slow build, slow execution, poor jargon laden syntax, etc.) to be very useful outside of academia. I am (perhaps obviously) biased, here, but I tend to just roll my eyes whenever any of my colleagues suggests we should use functional programming to solve a problem. There are actually very few real-world use cases where it's objectively better.
- wredue 3y ago
  Is “wanting evidence for constant silver bullet claims that never actually pan out” really “obviously biased”? It’s not just you. Functional Programming really does not adequately solve any of the problems that its advocates claim while refusing to provide any evidence. And it’s not “biased” to write these claims off.
  - epgui 3y ago
    I don't know what "silver bullet" claims you've heard, but I'm not sure how that is relevant to this thread. I don't think I've made any outlandish claims, or any claims that aren't substantiated by a preponderance of academic literature.
    - roenxi 3y ago
      I find this whole thread fascinating because nobody seems to have identified what functional programming is defined as (programmers can just use functions to code and end up with functional programming, it isn't an obscure style), who the advocates are or what they claim. And yet, without any substance, the debate rages.
      - epgui 3y ago
        > nobody seems to have identified what functional programming is defined as Nobody asked (until now, so thank you for asking!), and this is a fairly well discussed topic for anyone who cares to search! You will probably get a lot of slightly different answers depending on who you ask or where you look, but I think a very strong common thread is "referential transparency". Functional programming gives you that, and that is the property that makes FP particularly well suited for parallel computation. Referential transparency is related to the concept of "function purity" (in the sense that either one usually guarantees the other), which you will often hear people talk about as well. The two concepts are so intimately tied that sometimes I wonder if they're two different perspectives on the same thing. This, along with the fact that FP has been an active area of research (an important part of innovation) for a long time, is why I brought it up. https://en.wikipedia.org/wiki/Functional_programming https://en.wikipedia.org/wiki/Functional_programming https://en.wikipedia.org/wiki/Pure_function https://en.wikipedia.org/wiki/Pure_function https://en.wikipedia.org/wiki/Referential_transparency https://en.wikipedia.org/wiki/Referential_transparency https://softwareengineering.stackexchange.com/questions/293851/what-is-it-about-functional-programming-that-makes-it-inherently-adapted-to-para https://softwareengineering.stackexchange.com/questions/2938... --- > programmers can just use functions to code and end up with functional programming, it isn't an obscure style That's not how it works. Note that functional programming has nothing to do with merely "writing functions". --- > without any substance, the debate rages The substance is there and there is plenty of it, but learning requires work.

by epgui 3y ago

charcircuit 3y ago

The parent comment was talking about aligning programming languages with the hardware. I am not commenting about the viablity of those languages, but rather that if your goal is to write the most performant code by understanding the strengths and weaknesses of the hardware than using fp concepts is not the way to do it.

epgui 3y ago
I feel like in both of your comments you've changed the topic slightly. I responded to the following comment, which I interpreted literally: > Very little innovation in programming languages has happened regarding new realities at the hardware level especially transition from serial to parallel execution
AnimalMuppet 3y ago
Well... if code were pure (in the FP sense), then a "sufficiently smart compiler" could move it around to extract the maximum performance. But, as always, the sufficiently smart compiler never shows up. So we're left with the humans doing the tuning, and as you say, FP is kind of antithetical to that approach.
- Chris_Newton 3y ago
  But how will language performance evolve as the nature of the hardware our programs run on evolves? IMHO this is not an easy question to answer right now. C compilers don’t produce 100% optimal assembly language in all cases, but typically the assumptions they make are light. The executable code they output is somewhat predictable and often close enough to hand-optimised assembly in efficiency that we ignore the difference. But this whole approach to programming was originally designed for single-threaded execution on a CPU with a chunk of RAM for storage. What happens if we never find a way to get a single core to run much faster but processors come with ever more cores and introduce other new features for parallel execution? What happens if we evolve towards ever more distributed systems, but farming out big jobs to a set of specialised components in the cloud at a much lower level than we do today? What happens if systems start coming with other kinds of memory that have different characteristics to RAM as standard, from content-addressable memory we already have today to who-knows-what as quantum technology evolves? If we change the rules then maybe a different style of programming will end up being more efficient. It’s true that today’s functional programming languages that control mutation and other side effects usually don’t compile down to machine code as efficiently as a well-written C program can. The heavier runtimes to manage responsibilities like garbage collection and the reliance on purely functional data structures that we don’t yet know how to convert to efficient imperative code under the hood are bottlenecks. But on the other hand, those languages can make much stronger assumptions than a lower-level language like C in other ways, and maybe those assumptions will allow compilers to safely allocate different behaviour to new hardware in ways that weren’t possible before, and maybe dividing a big job into 500 quantum foobar jobs that each run half as fast as a single-threaded foobaz job still ends up doing the job 200x faster overall.
  - kaba0 3y ago
    > C compilers don’t produce 100% optimal assembly language in all cases, but typically the assumptions they make are light. The executable code they output is somewhat predictable Lol, since when? C compilers literally will run some of your code at build time, and only write the results into the binary and they do all sort of crazy "mental gymnastics" to make people believe it is still a dumb single-pass compiler.

sidlls 3y ago

"FP" camps tend to come in two flavors: "I'm a mathematician writing a computer program, and all problems will be made to look like math problems even if it means the program becomes an inscrutable mess of types and dense syntax" and "functional-ish idioms are included". The latter is useful, sometimes, for cloud computing and parallel computation; the former tends to have too many problems (slow build, slow execution, poor jargon laden syntax, etc.) to be very useful outside of academia. I am (perhaps obviously) biased, here, but I tend to just roll my eyes whenever any of my colleagues suggests we should use functional programming to solve a problem. There are actually very few real-world use cases where it's objectively better.

wredue 3y ago
Is “wanting evidence for constant silver bullet claims that never actually pan out” really “obviously biased”? It’s not just you. Functional Programming really does not adequately solve any of the problems that its advocates claim while refusing to provide any evidence. And it’s not “biased” to write these claims off.
- epgui 3y ago
  I don't know what "silver bullet" claims you've heard, but I'm not sure how that is relevant to this thread. I don't think I've made any outlandish claims, or any claims that aren't substantiated by a preponderance of academic literature.
  - roenxi 3y ago
    I find this whole thread fascinating because nobody seems to have identified what functional programming is defined as (programmers can just use functions to code and end up with functional programming, it isn't an obscure style), who the advocates are or what they claim. And yet, without any substance, the debate rages.
    - epgui 3y ago
      > nobody seems to have identified what functional programming is defined as Nobody asked (until now, so thank you for asking!), and this is a fairly well discussed topic for anyone who cares to search! You will probably get a lot of slightly different answers depending on who you ask or where you look, but I think a very strong common thread is "referential transparency". Functional programming gives you that, and that is the property that makes FP particularly well suited for parallel computation. Referential transparency is related to the concept of "function purity" (in the sense that either one usually guarantees the other), which you will often hear people talk about as well. The two concepts are so intimately tied that sometimes I wonder if they're two different perspectives on the same thing. This, along with the fact that FP has been an active area of research (an important part of innovation) for a long time, is why I brought it up. https://en.wikipedia.org/wiki/Functional_programming https://en.wikipedia.org/wiki/Functional_programming https://en.wikipedia.org/wiki/Pure_function https://en.wikipedia.org/wiki/Pure_function https://en.wikipedia.org/wiki/Referential_transparency https://en.wikipedia.org/wiki/Referential_transparency https://softwareengineering.stackexchange.com/questions/293851/what-is-it-about-functional-programming-that-makes-it-inherently-adapted-to-para https://softwareengineering.stackexchange.com/questions/2938... --- > programmers can just use functions to code and end up with functional programming, it isn't an obscure style That's not how it works. Note that functional programming has nothing to do with merely "writing functions". --- > without any substance, the debate rages The substance is there and there is plenty of it, but learning requires work.