Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Why ML/OCaml are good for writing compilers (1998)

flint.cs.yale.edu

Post reply on HN
Print view View original

51–60 of 151 posts

Re: Why ML/OCaml are good for writing compilers (1998)

#51

Post by rbehrends »

Dangeranger wrote: post #3

After learning Elm I wanted to understand ML/OCaml a bit more, so I worked through some documentation from the OCaml site and walked away pleasantly surprised. After using it for a couple of weeks I am confused why ML/OCaml aren't more popular. They are safe, functional, stable, fast, and have great tooling. They seem poised to take over the functional domain. While the syntax took a little getting used to ( emphasis…

As a rule, functional programming languages tend to have trouble with gaining adoption. It's simply a programming paradigm that a great many programmers don't seem to be comfortable with.

Now, the ML family of languages (SML, OCaml, F#) is technically a family of multi-paradigm, functional-first languages, but that doesn't help with clearing the "functional" hurdle in popular perception.

Re: Why ML/OCaml are good for writing compilers (1998)

#52

Post by rubiquity »

atombender wrote: post #40
hongbo_zhang wrote: post #30

For web developers who are looking for an industrial strength functional language instead of JS, OCaml probably has the best story here. Actually it has two OCaml->JS compilers of very high quality The first one, js_of_ocaml, could bootstrap the whole compiler several years ago(probably the first one there). The recent one, https://github.com/bloomberg/bucklescript , push the JS compilation into next level, it genera…

I'm optimistic about Reason, Facebook's new syntax "skin" on top of OCaml. I find OCaml's syntax to be quite gnarly; of the MLs, F# is probably the cleanest and most modern-feeling. Something like F# without the .NET stuff could have been amazing.

The good news is that you can have your cake and eat it too! Reason is a front-end to the OCaml compiler and BuckleScript is a back-end. Your Reason programs can be compiled to JS via BuckleScript. Yay!

Re: Why ML/OCaml are good for writing compilers (1998)

#53

Post by rubiquity »

hyperpallium wrote: post #50

How are simple parsers written in ML (or ocaml)? You can't use the coding style used for recursive descent in the Dragon compiler book, without using mutable variables. Do you have to use parser combinators, which have their own limitations?

You can do mutation in both Standard ML and OCaml. If I recall, Robert Harper's book on Standard ML starts off with a recursive descent parser.

Re: Why ML/OCaml are good for writing compilers (1998)

#54

Post by lobster_johnson »

rubiquity wrote: post #52
atombender wrote: post #40

Earlier quoted context omitted.

I'm optimistic about Reason, Facebook's new syntax "skin" on top of OCaml. I find OCaml's syntax to be quite gnarly; of the MLs, F# is probably the cleanest and most modern-feeling. Something like F# without the .NET stuff could have been amazing.

The good news is that you can have your cake and eat it too! Reason is a front-end to the OCaml compiler and BuckleScript is a back-end. Your Reason programs can be compiled to JS via BuckleScript. Yay!

Nice!

Re: Why ML/OCaml are good for writing compilers (1998)

#55

Post by edgyswingset »

atombender wrote: post #40
hongbo_zhang wrote: post #30

For web developers who are looking for an industrial strength functional language instead of JS, OCaml probably has the best story here. Actually it has two OCaml->JS compilers of very high quality The first one, js_of_ocaml, could bootstrap the whole compiler several years ago(probably the first one there). The recent one, https://github.com/bloomberg/bucklescript , push the JS compilation into next level, it genera…

I'm optimistic about Reason, Facebook's new syntax "skin" on top of OCaml. I find OCaml's syntax to be quite gnarly; of the MLs, F# is probably the cleanest and most modern-feeling. Something like F# without the .NET stuff could have been amazing.

Fable: http://fable.io/

It's able to self-host as well. Check it out at http://fable.io/repl

F# also runs on .NET Core, which is cross-platform and comes with a good CLI. Documented, too: https://docs.microsoft.com/en-us/dotnet/articles/fsharp/tuto...

Re: Why ML/OCaml are good for writing compilers (1998)

#56

Post by vmasto »

mhink wrote: post #45
vmasto wrote: post #2

For anyone interested and isn't aware yet Facebook is developing Reason, a layer over OCaml. I've been fiddling with it for the past couple of weeks and coming from JavaScript I personally found the experience generally enjoyable. https://facebook.github.io/reason/

Hah! Thanks for the link- I discovered this gem just now in their list of comparisons to JS syntax: Javascript | Reason --------------+---------------------------- const x = y; | let x = y; let x = y; | reference cells var x = y; | No equivalent (thankfully)

:) Yeah, unfortunately JavaScript can only be improved by educating people not to use the horrible parts (rather than fixing/deprecating them which is not possible). const and let were extremely necessary.

Re: Why ML/OCaml are good for writing compilers (1998)

#57

Post by tpetricek »

atombender wrote: post #40
hongbo_zhang wrote: post #30

For web developers who are looking for an industrial strength functional language instead of JS, OCaml probably has the best story here. Actually it has two OCaml->JS compilers of very high quality The first one, js_of_ocaml, could bootstrap the whole compiler several years ago(probably the first one there). The recent one, https://github.com/bloomberg/bucklescript , push the JS compilation into next level, it genera…

I'm optimistic about Reason, Facebook's new syntax "skin" on top of OCaml. I find OCaml's syntax to be quite gnarly; of the MLs, F# is probably the cleanest and most modern-feeling. Something like F# without the .NET stuff could have been amazing.

I can confirm that the story of F# on the JS ecosystem is already quite good and is getting better every day. As already mentioned, Fable (http://fable.io) is the way to go today. I did two things that involve "writing compilers" using F# that target the web and did not have any notable issuues.

- My coeffects page (http://tomasp.net/coeffects) is an implementation of a simple ML-like language with coeffect type system. It was written using FunScript, which is a precursor of Fable - Fable improved many things, but this was over a year ago when it was not around yet.

- The Gamma (https://thegamma.net) is a web-based language for doing simple data science work and the compiler for that is written all in Fable. It works perfectly and integrates neatly with things like virtual-dom (source code is on GitHub https://github.com/the-gamma/thegamma-script)

Re: Why ML/OCaml are good for writing compilers (1998)

#58

Post by throwaway7645 »

dogfishbar wrote: post #39
poizan42 wrote: post #16

Earlier quoted context omitted.

At computer science at the University of Copenhagen F# has been used for the introduction courses the past couple of years, which as far as I know has been a big success, so I'm doubtful of it not being beginner friendly

I have been teaching OCaml in CS1 at Boston College for 4 years now. Of hundreds of students who went on to learn Java in our CS2 course (joining Python-trained students from other sections of CS1), nearly unanimous happy campers. When OCaml is their first programming language, they're good to go.

Is the course material online?

Re: Why ML/OCaml are good for writing compilers (1998)

#59

Post by hongbo_zhang »

tpetricek wrote: post #57
atombender wrote: post #40

Earlier quoted context omitted.

I'm optimistic about Reason, Facebook's new syntax "skin" on top of OCaml. I find OCaml's syntax to be quite gnarly; of the MLs, F# is probably the cleanest and most modern-feeling. Something like F# without the .NET stuff could have been amazing.

I can confirm that the story of F# on the JS ecosystem is already quite good and is getting better every day. As already mentioned, Fable ( http://fable.io ) is the way to go today. I did two things that involve "writing compilers" using F# that target the web and did not have any notable issuues. - My coeffects page ( http://tomasp.net/coeffects ) is an implementation of a simple ML-like language with coeffect type…

Indeed, fable is a very neat project, but to be honest, it is not as mature as BuckleScript at this time.

For example, it takes around 20~80ms to compile a single file for BuckleScript, while Fable would talk 10x more to compile.

Its generated code is pretty but its performance is not very good, see this issue (https://github.com/fable-compiler/Fable/issues/646) "this can make a difference in speed of up to about six or seven times for tight loop code using tuples, records, lists, unions, etc.(compared with BuckleScript)"

But Fable is a nice project, JavaScript platform is large enough to have both :-)

Re: Why ML/OCaml are good for writing compilers (1998)

#60

Post by emmelaich »

haskellandchill wrote: post #42
atombender wrote: post #40

Earlier quoted context omitted.

I'm optimistic about Reason, Facebook's new syntax "skin" on top of OCaml. I find OCaml's syntax to be quite gnarly; of the MLs, F# is probably the cleanest and most modern-feeling. Something like F# without the .NET stuff could have been amazing.

I find OCaml's syntax simple and clear. I don't get the reason for Reason, but hope it leads to more OCaml adoption.

I get the reason* for Reason even though it may ostensibly be a superficial one. There was a post by someone on HN saying they started using Reason and ended up using straight Ocaml.

* My earliest memories of attempting to use Ocaml was pasting something directly from a beginner's tutorial into ocamli and getting a baffling error message. I think it had to do with use of double semicolons vs single semicolons. Yet that wasn't mentioned in the entire tutorial.

Post reply on HN