Gleam doesn't compile to Erlang source anymore (gleam.run)

276 points by ingve 14 hours ago

jmcgough 4 minutes ago

Louis is amazing. So cool to see how he's grown this project since starting it.

0x69420 10 hours ago

to those curious, erlang abstract form[1] is the AST representation used by the erlang compiler/etc. per [1], you can see that it's canonically made of erlang terms, and you have easy access to routines for manipulating this representation from the standard library; it's really comfy when you need it! it's also the target elixir compiles down to, and the representation manipulated by parse transforms, which in base erlang are the way syntactic sugar (notably qlc[2] and some of the more cutesy pattern matches in merl[3] (which, in turn, manipulates the very same representation to do its job. very meta!)) is done.

most BEAM languages actually settle on erlang abstract format. you'd think core erlang would be more common since it feels more like a traditional functional IR, but basically only LFE does this, because it's a moving target without any particular stability guarantees from release to release.

1: https://www.erlang.org/doc/apps/stdlib/erl_parse.html#t:abst...

2: https://www.erlang.org/doc/apps/stdlib/qlc.html#q/2

3: https://www.erlang.org/doc/apps/syntax_tools/merl.html

lpil 4 hours ago

giancarlostoro 7 hours ago

Erlang is one of those runtimes I've loved since learning about it all the way back in 2008, but I never took time to learn the syntax, but Elixir and Gleam have had me fiddling with the Erlang VM over the years. Happy to see Gleam growing into maturity.

ryan-duve 5 hours ago

I just learned Erlang this year and I love the syntax. Ending expressions with periods took getting used to, but capital first letters distinguishing variables, non-rebindable variables, semicolons between function clauses, a lack of boilerplate (defmodule et al), a fraction of end keywords, commas separating expression, ... all make for a very fun to use and ergonomic language, IMO.

I haven't tried Gleam yet, though. I'm interested in the focus on simplicity but a little wary because I understand they sacrificed niceties to minimize the language footprint, e.g., pattern matching in function heads. I intend to give it a shot the next time I'm greenfielding something.

mahboi 2 hours ago

Erlang is my favorite functional language out of all the ones I've tried. The matchers, guards, etc are all done very well. But I don't like functional. I used to think it was cool, gave it a real chance using Erlang for years, and eventually decided it's not a good fit for many use cases. Like at some point the neatness of doing all loops as recursion wears off and it's just tiring. It's not like CS algo homework, and even there you often want DP/memoization.

Edit: pure* functional

sodapopcan an hour ago

SoftTalker 3 hours ago

I'm the same. I thought I was an oddball because so many people seemed to prefer Elixir but I like Erlang and its syntax. I wish I had more chances to use it at work but so far it's just been for hobby projects or playing with.

macintux 2 hours ago

I was fortunate enough to use Erlang professionally for a couple of years. I agree: the syntax is quite comfortable.

ch4s3 7 hours ago

I'd say if you know and like Rust, then Gleam should be easy to pick up but otherwise I'd try Elixir. You can learn most of the language in a few days and be experimenting with BEAM and supervision concepts basically on day one. As a learning exercise I think its worth peoples' time because actors/processes are one of the concurrency models you don't see everywhere but solve interesting problems well.

lpil 7 hours ago

I don't think that's the case, Rust and Gleam have almost nothing in common beyond having static type systems, and those type systems are very different too.

https://gleam.run/frequently-asked-questions/#How-does-Gleam...

ch4s3 7 hours ago

bmitc 6 hours ago

MichaelNolan 8 hours ago

Gleam is such a beautiful language. I wish I had the opportunity to use it more. If it could compile (transpile) to a native target like rust or go, it would be truly perfect.

rapnie 6 hours ago

I would love to see support for wasm and wasi.

whalesalad 8 hours ago

I am working on a language called blasphemy which intends to do this.

znpy 7 hours ago

Looking forward to be able to claim to be “proficient in blasphemy” on my cv! /s

packetlost 7 hours ago

I feel like Go would be a great backend target for Gleam

lpil 7 hours ago

Go's garbage collection isn't well suited for an immutable language like Gleam, so the performance would likely be disappointing compared to other targets.

ch4s3 7 hours ago

packetlost 7 hours ago

phplovesong 5 hours ago

For that there is Lisette. Close to gleam, compiles to Go.

phplovesong 5 hours ago

You just described Lisette. Its very close to gleam, and compiles to Go.

zachrip 10 hours ago

Shout out to Giacomo's twitch streams. He has taught me about some features of Gleam, Rust, and on top of that he's just a very chill person. He takes time away from his focus to answer questions politely and without judgement. There are dozens of programming streams where the streamer forgets to leave their ego at the door and he is not one of them. I highly recommend following it.

giacomocava 7 hours ago

Thank you so much!! Reading this really made my day <3

oDot 3 hours ago

Thank you for Squirrel as well!

olexsmir 6 hours ago

massive +1, been watching his streams from time to time, and the man is the definition of a humble and chill person

giacomocava 4 hours ago

Aww thank youuu

oDot 3 hours ago

The Gleam community is generally very very nice. I maintain about 200k lines of Gleam[0][1], and they have generally accommodated even my stupidest posts on Discord.

The language itself is as welcoming. Even LLMs are less cranky and output nicer code, not having to deal with React.

[0]: https://blisswriter.app/

[1]: https://nestful.app/

speerer 10 hours ago

...And he animates his presentations by hand-drawing each frame transition, which speaks volumes.

[edit - this might have been ambiguous. I meant that it shows he really cares about the fine details.]

jxf 9 hours ago

Do you have an example you especially like?

speerer 8 hours ago

dematz 8 hours ago

cod1r 9 hours ago

yea he is super nice.

giacomocava 4 hours ago

Thank you! Too kind

tiffanyh 5 hours ago

The title is a bit misleading because one might imply that Gleam no longer compiles to something Erlang can use (not true).

From the article:

> Over the last few months Giacomo Cavalieri has entirely rewritten Gleam's Erlang code generator that has an entirely different design, and most notably, outputs a different format. Previously Gleam generated Erlang source code, now it generates Erlang abstract forms.

lpil 4 hours ago

The title says it no longer compiles to Erlang source. That's true, it now compiles to an IR of the Erlang compiler.

olexsmir 6 hours ago

I love seeing how gleam gets better and better with every release, sadly I dont have any projects where I could use gleam :(

desireco42 17 minutes ago

I will just say, as of recently, especially thanks to AI, I've been doing projects in Gleam, I am on third Gleam project and it has been very pleasant experience. It takes longer to write but it is much shorter, easier to follow and much more easier to update and change.

__jonas 9 hours ago

Pretty exciting change that I didn’t see coming —- I wonder if someone will end up implementing an integration with the Whatsapp Erlang debugger

lpil 8 hours ago

The only thing that would be needed for this is for 2 flags to be passed to the Erlang compiler. It would be very trivial!

impoppy 8 hours ago

This raises an obvious question. Why Gleam team weren't doing that in the first place? Obviously they didn't have direct Gleam AST -> Erlang source pipeline, they must have had to build some their own custom Erlang AST representation that they then translated into the source code.

lpil 8 hours ago

We did not (and still don't) have an internal Erlang AST representation in the compiler. Previously we did have a Gleam AST -> printing algebra -> Erlang source pipeline, now we construct a buffer of bytes with the data encoded as Erlang Term Format.

Source was the previous target as at the time Erlang Abstract Terms was not established as the go-to format (Core Erlang was more popular but it did not have a stable API outside of the BEAM, so Gleam's in-Rust compiler could not construct it), and due to the newness of the language having an "escape hatch" where one could abandon Gleam and eject to Erlang was highly valuable. It also meant we could use the Erlang build tool until the Gleam one was ready for use.

vortegne 11 hours ago

Congratulations to the team! I love Gleam and am genuinely having fun every time I write Gleam code.

lexx 9 hours ago

Amazing news! Thank you!

tasuki 2 hours ago

...and many other improvements!

I was surprised to find Matt Mullenweg among the sponsors.

PKop 4 hours ago

> "Transpiler" means a compiler that outputs a human-readable format, such as source code. It's a cool sounding word, but most the time people use it to imply that a given compiler is in some way inferior. This is very silly, as there is nothing about compiling to a human-readable format that makes a compiler easier to implement.

Ok but this footnote comes at the end of a paragraph describing how the previous transpiler implementation was inferior to the new compiler. It's ok to make these distinctions.

lpil 18 minutes ago

The old one had an inferior implementation, but that is unrelated to the output format. We also have a new Erlang source code generator that is used predominantly in the compiler test suite, and it too is superior.

karel-3d 8 hours ago

What is Gleam? Where would I want to use it?

All I understand from the frontpage is that it's typesafe. Good I guess? Then there is something about Erlang which I never used.

lpil 7 hours ago

Gleam is a simple functional programming language which leans into static typing , friendly tooling, and a one-way-to-do-it style. You'd want to use it if you enjoy the programming experience it provides.

jeltz 7 hours ago

It is if you want Erlang but typesafe and with a modern syntax. And why would you want Erlang? Erlang was built for making it easy to build fault-tolerant concurrent applications, for example in telecom.

jazzypants 8 hours ago

Let me guess: still no string interpolation in a language ostensibly intended for building user interfaces?

lpil 8 hours ago

Gleam is not ostensibly intended for building user interfaces.

whalesalad 8 hours ago

I still don't know what gleam is for tbh. I like it conceptually. But interop with for instance elixir libraries is not as seamless as you'd like.

__jonas 8 hours ago

lpil 7 hours ago

jazzypants 7 hours ago

Then, why is JavaScript a compilation target? If you're not using it on the client-side, then why not stay exclusive to the BEAM?

lpil 7 hours ago

yladiz 7 hours ago

dematz 8 hours ago

gleam is very much a language of "no" which if you like that, cool, if not, also cool :)

phcreery 10 hours ago

The misuse of commas is distracting; at least it’s better than reading ai blogs.

gamache 9 hours ago

Your semicolon would be more effective as a comma followed by "but". HTH

dominikh 9 hours ago

Which commas are misplaced?

Joker_vD 9 hours ago

Before the "and", "but", "so", "while", etc. — while most European languages, indeed, (usually) require commas before conjunctions, English is following a somewhat reversed convention. Well, at least the author remembered that they need to omit a comma before "that".

shakna 8 hours ago

pipe01 9 hours ago

sarchertech 8 hours ago

nwalkr 9 hours ago

idk, i'm not sure about wording. erlang abstract form still is erlang source, it's ast of erlang source text. one call to erl_prettypr:format and text source is back. word 'transpiler' is still there and there is nothing "pejorative" in it, it's transpilers all the way down everywhere.

but talking pejorative, i was surprised. my opinion of gleam was already pretty low, but i did not expect to see post-1.0 compiler emitting text erlang source. maybe it's not that good of idea to implement compiler in language completely foreign to target ecosystem.

lpil 8 hours ago

I don't think your "it is source as you can convert it back into source" argument holds water as all the Erlang formats can be decompiled into Erlang source code, including the final bytecode itself.

I think you're overthinking the cost of compiling to source, and also underestimating how common it is.

capitanazo77 5 hours ago

When will they change their image to not look like girl toys?

Imagine a doctor about to do surgery and opening a toy box

atollk 5 hours ago

I have never seen a software developer be insecure about their manhood because of the programming language they use. This is equal parts funny and sad.

hinkley 3 hours ago

I’m old enough to remember VB developers so unfortunately cannot concur.

omnimus 5 hours ago

It's not surgery is it. It's programming language and their maintainers like it.

throwaway27448 5 hours ago

I'm struggling to imagine how this even comes up.

ginkogruen 5 hours ago

Imagine your doctor is about to begin surgery and walks in with a camel, a crab and a gopher.

hinkley 3 hours ago

And a weird little guy who looks like an artist’s eraser.