Gleam doesn't compile to Erlang source anymore

124 pointsposted 6 hours ago
by ingve

35 Comments

zachrip

3 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.

speerer

3 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.]

cod1r

2 hours ago

yea he is super nice.

0x69420

3 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

MichaelNolan

an hour 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.

whalesalad

25 minutes ago

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

impoppy

an hour 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

38 minutes 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.

__jonas

an hour 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

37 minutes 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!

lexx

2 hours ago

Amazing news! Thank you!

karel-3d

28 minutes 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.

jazzypants

an hour ago

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

lpil

32 minutes ago

Gleam is not ostensibly intended for building user interfaces.

whalesalad

22 minutes 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

12 minutes ago

I use it mostly for web APIs / services, it's great for that!

Interop is not seamless since Elixir does not have the same static type system, but it is possible and that does help sometimes. When resizing images for example, I fall back to Elixir's bindings to libvips. I've also used Oban from Gleam in the past.

dematz

an hour ago

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

vortegne

3 hours ago

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

phcreery

3 hours ago

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

gamache

2 hours ago

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

dominikh

2 hours ago

Which commas are misplaced?

Joker_vD

2 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

an hour ago

Apart from in Australian [0] and Canadian [1] English, where it is generally optional, but used where it can increase clarity or meter.

[0] Australian Government Publishing Service's Style Manual for Authors, Editors and Printers, ISBN: 978 0 7016 3648 7

[1] The Canadian style: a guide to writing and editing https://archive.org/details/canadianstylegui0000unse

pipe01

an hour ago

As a non-native English speaker I'm always so self conscious when using commas, it feels like I'm always using either too many or too few

john_strinlai

36 minutes ago

i dont think anyone actually cares unless you are in english class or someone wants to feel smug on the internet (you can ignore the 2nd one completely).

zulux

39 minutes ago

Don't worry about it.

The lack or excess of commas doesn't upset any reasonable person in the slightest.

steele

an hour ago

You're doing fine. English grammar pedants speak infrequently. Mostly due to the disinterest of the listener.

sarchertech

an hour ago

You do need a comma before a conjunction if it connects two independent clauses.

Joker_vD

33 minutes ago

So it's "You do need a comma before a conjunction, if it connects two independent clauses" then — "you need a comma before a conjunction" and "it connects two independent clauses" are two fully formed simple sentences, each having its own subject and predicate. See what I mean?

And almost nobody writes sentences like "I love her and she loves me back" with a comma before "and".

nwalkr

2 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

34 minutes 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.