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.
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.
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.
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".
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).
Informally, commas are "misused" regularly even by native writers, and almost no one notices or cares unless the misuse is frequent and egregious.
Formally, most comma use is an issue of style, not grammar, and style guides differ on when they should and shouldn't be used. The main rule that's actually a matter of grammar is this: commas cannot be used to join two "clauses" (phrases which could be independent sentences) without a conjunction.
English has no central authority, so the lines between grammar and style can get fuzzy. Most guides would say you need an "and" after the second comma, but some make an exception if the clauses are "very short and alike in form". See Wikipedia's article Comma splice if you are interested in the pedantics. https://en.wikipedia.org/wiki/Comma_splice
You still didn't answer: am I supposed to write "I'm eating a hot dog she's listening to radio" without a comma for that sentence to be grammatical? Or am I supposed to always insert "and" into it?
With or without a comma, without a conjunction like "and" the example is a run on sentence and is ungrammatical. You should join the clauses with a conjunction, and including a comma before the conjunction is a common style.
There's a caveat where some style guides permit using a comma without a conjunction in specific contexts, but most don't.
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".
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.
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.
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.
Yeah. I know. I use it every day. That doesn't answer my question. Why would I want to write something in Gleam if I want it to run in a JavaScript engine? When would that ever make sense? Could you please just engage with me in good faith?
Multiple compilation targets require increased implementation complexity so you would think they would have a good reason for when you would compile to one target or the other. I couldn't find any information about it on their website, so I was hoping you would actually respond with something helpful rather than... that.
So, you started by making a pointed comment about that the language has no string interpolation when it's ostensibly for building UIs, so I'm not sure why you're surprised you're getting responses like mine or the one from lpil. Gleam is not ostensibly meant for building UIs just because it targets JS, and while you don't get string interpolation in the way you might get in other languages you can go pretty far with the <> syntax.
To answer your question about why you would use Gleam when you're running code in a JS engine, it's the same about any language that compiles down to another, such as Clojure, and you can take your pick of those reasons: preference, syntax, pragmatism, etc. I'm not sure what kind of answer you're looking for beyond that.
I'm looking for the intention behind it. They chose two compilation targets. That made things harder. They had a reason. That's what I'm asking about.
None of your reasons ("preference, syntax, pragmatism") fully explain the situation without more context. Whose preference? What syntax are users even seeing? Why is it pragmatic?
Compilation targets are generally chosen based on performance characteristics and where the code is actually expected to be run. If you're not expecting the code to run on the client, then there's no reason to use JavaScript. V8 performance is better when single-threaded, but then why use the actor model?
When I go to the ClojureScript website, they have a whole section about why they chose JavaScript as a compilation target[0]. Notably, it mentions the word "client" multiple times.
JavaScript is useful in lots of places, and even if one compile target is especially good for in-browser user interfaces that doesn't mean that language is specifically intended for user interface development.
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.
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.
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.
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.
The concurrency model in Go is also poorly suited to the BEAM's process model. Goroutines share a heap so you can't do a lot of things safely that processes can do. Having independent memory space for a process allows you to free it safely when work is done without GCing everything and you can also safely share data because you have a copy not a ref.
Surprisingly yes! JavaScript's allocator and garbage collection system is quite well suited to immutable programming.
Rust is a very poor compile target as the compiler is slow and not commonly available, and the aspects of Rust that make it good for humans to write make it a poor choice for compilers to target. With humans the produced code is verified, but with a compiler the compiler is what is to be verified, so the inflexibility of Rust are largely a hindrance compared to other native compilation targets.
What lower-level language do you think aside from rust which can be more helpful for the purposes of being a compile target, nim/D both support garbage collection and non garbage collection, so would languages like these be more preferable
I really love gleam and its community and I would really really love if gleam could be more like golang though, which can help it in compiling to machine code
gleam language but with the developer experience of golang (cross portability/small binaries/fast compiled language which is fast to compile) is honestly one of my fever dreams and I would love to know if it can ever be a reality!
For that sort of compilation target more flexibility is beneficial, so C, Wasm, LLVM IR, Cranelift IR etc are better than Go, Nim, and D in my opinion.
> cross portability/small binaries/fast compiled language which is fast to compile
You don't need native compilation to build fast single file executables for a program, there's ways one can achieve this with Gleam today. Bundling the BEAM into your Gleam application executable with something like Gleepack is one option, and this will produce smaller executables than Go will by default for many applications.
I don't get the impression that javascript is among Gleam's targets because of performance.
- server target: BEAM
- client target: js
Once you've covered those bases, you're kind of done.
If the server needs to do something special in an OS process... might as well let the OS mediate that interaction so that it can be fully generic, rather than trying to bend the language around whatever the unknown action might be.
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.
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.
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.
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.
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.
I think a Rust programmer is more likely to prefer Gleam to Elixir, but I don't think there is much link between Gleam and Rust, and I especially do not thing that Gleam should only be considered over Elixir if you are already a Rust programmer.
You said:
>I'd say if you know and like Rust, then Gleam should be easy to pick up but otherwise I'd try Elixir.
This is way too strong and narrow statement. Gleam is statically typed garbage collected language, closer to OCaml than Rust. Elixir if you like dynamically typed instead.
Nah, the gradual angle is not what makes a type system tricky to implement. Plus we have published a few papers discussing how we are typing Elixir and how our approach is sound.
It's very possible that I'm misunderstanding you! I'm mostly just saying that Gleam is very unlike Rust, so if you pick it or avoid it for Rust related reasons you may not be making the most informed decision.
The languages that Gleam is most like might be Standard ML, OCaml, Elm, and F#.
You seem to be interpreting the statements as technical comparisons of the languages, but ch4s3 was (by my read) commenting on the overall ability of a programmer to jump from one language to another.
That is: they aren't similar languages on a technical level, but if you know Rust, you should be able to make the jump to Gleam pretty quickly.
Aye, I am saying that jumping from Rust to Gleam isn't easy because the languages are so different. "How do I do X in Gleam like I would in Rust" is one of the most common categories of support question from newcomers who assumed they were similar.
I use Rust and prefer Elixir over Gleam because Elixir has Lisp-style macros (Gleam doesn't), uses OTP directly, has the fantastic IEx REPL (Gleam has no counterpart), and has Phoenix, the best web framework I've ever used.
> I'd say if you know and like Rust, then Gleam should be easy to pick up
I think by sentiments like this, people mean if you know unions, records, and pattern matching then you'll more easily pick up another language that has unions, records, and pattern matching.
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.
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.
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.
> Like at some point the neatness of doing all loops as recursion wears off and it's just tiring.
Odd, but I believe you, lol. Elixir's list comprehensions take a `:reduce` option which makes accumulating values a bit more "familiar" and I often use over `reduce`:
for a <- list, reduce: []
acc ->
[a | acc]
end
Not sure if there is something like that in Erlang (or Gleam for that matter).
If you already have a list in Erlang, you can use map and the foldl/foldr reducers. But there's no general for-loop. You're expected to use tail recursion.
Also tbh, I don't like reduce either. I agree with that article posted on HN a while back about devs not liking reduce. Just want to insert into my list or whatever.
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.
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.
> "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.
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.
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.
I love this language, but I have to wonder how much harder it is to grow a niche language these days when everyone is just telling Claude what to build for them. It seems like LLM friendliness is going to become the new benchmark for adoption if it hasn't already, and I find that pretty sad.
vortegne | 10 hours ago
zachrip | 10 hours ago
speerer | 10 hours ago
[edit - this might have been ambiguous. I meant that it shows he really cares about the fine details.]
jxf | 8 hours ago
dematz | 8 hours ago
speerer | 8 hours ago
irickt | 7 hours ago
cod1r | 9 hours ago
giacomocava | 4 hours ago
giacomocava | 7 hours ago
oDot | 3 hours ago
olexsmir | 6 hours ago
giacomocava | 4 hours ago
oDot | 3 hours ago
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/
0x69420 | 10 hours ago
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
https://github.com/lfe/lfe/blob/387d0aa1092bdda0ca17481869e8...
https://github.com/lfe/lfe/blob/387d0aa1092bdda0ca17481869e8...
phcreery | 10 hours ago
dominikh | 9 hours ago
Joker_vD | 9 hours ago
pipe01 | 8 hours ago
tenuousemphasis | 8 hours ago
steele | 8 hours ago
zulux | 8 hours ago
The lack or excess of commas doesn't upset any reasonable person in the slightest.
john_strinlai | 8 hours ago
GrantMoyer | 7 hours ago
Formally, most comma use is an issue of style, not grammar, and style guides differ on when they should and shouldn't be used. The main rule that's actually a matter of grammar is this: commas cannot be used to join two "clauses" (phrases which could be independent sentences) without a conjunction.
Joker_vD | 7 hours ago
GrantMoyer | 6 hours ago
Joker_vD | 5 hours ago
GrantMoyer | 4 hours ago
There's a caveat where some style guides permit using a comma without a conjunction in specific contexts, but most don't.
shakna | 8 hours ago
[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
sarchertech | 8 hours ago
Joker_vD | 8 hours ago
And almost nobody writes sentences like "I love her and she loves me back" with a comma before "and".
gamache | 9 hours ago
lexx | 9 hours ago
nwalkr | 9 hours ago
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 think you're overthinking the cost of compiling to source, and also underestimating how common it is.
__jonas | 9 hours ago
lpil | 8 hours ago
jazzypants | 8 hours ago
dematz | 8 hours ago
lpil | 8 hours ago
whalesalad | 8 hours ago
__jonas | 7 hours ago
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.
lpil | 7 hours ago
jazzypants | 7 hours ago
yladiz | 7 hours ago
jazzypants | 7 hours ago
Multiple compilation targets require increased implementation complexity so you would think they would have a good reason for when you would compile to one target or the other. I couldn't find any information about it on their website, so I was hoping you would actually respond with something helpful rather than... that.
yladiz | 7 hours ago
To answer your question about why you would use Gleam when you're running code in a JS engine, it's the same about any language that compiles down to another, such as Clojure, and you can take your pick of those reasons: preference, syntax, pragmatism, etc. I'm not sure what kind of answer you're looking for beyond that.
jazzypants | 6 hours ago
None of your reasons ("preference, syntax, pragmatism") fully explain the situation without more context. Whose preference? What syntax are users even seeing? Why is it pragmatic?
Compilation targets are generally chosen based on performance characteristics and where the code is actually expected to be run. If you're not expecting the code to run on the client, then there's no reason to use JavaScript. V8 performance is better when single-threaded, but then why use the actor model?
When I go to the ClojureScript website, they have a whole section about why they chose JavaScript as a compilation target[0]. Notably, it mentions the word "client" multiple times.
[0] https://clojurescript.org/about/rationale
lpil | 7 hours ago
impoppy | 8 hours ago
lpil | 8 hours ago
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.
MichaelNolan | 8 hours ago
whalesalad | 8 hours ago
znpy | 7 hours ago
packetlost | 7 hours ago
lpil | 7 hours ago
ch4s3 | 7 hours ago
packetlost | 6 hours ago
lpil | 6 hours ago
Rust is a very poor compile target as the compiler is slow and not commonly available, and the aspects of Rust that make it good for humans to write make it a poor choice for compilers to target. With humans the produced code is verified, but with a compiler the compiler is what is to be verified, so the inflexibility of Rust are largely a hindrance compared to other native compilation targets.
Imustaskforhelp | 5 hours ago
I really love gleam and its community and I would really really love if gleam could be more like golang though, which can help it in compiling to machine code
gleam language but with the developer experience of golang (cross portability/small binaries/fast compiled language which is fast to compile) is honestly one of my fever dreams and I would love to know if it can ever be a reality!
lpil | 5 hours ago
> cross portability/small binaries/fast compiled language which is fast to compile
You don't need native compilation to build fast single file executables for a program, there's ways one can achieve this with Gleam today. Bundling the BEAM into your Gleam application executable with something like Gleepack is one option, and this will produce smaller executables than Go will by default for many applications.
__MatrixMan__ | 6 hours ago
- server target: BEAM
- client target: js
Once you've covered those bases, you're kind of done.
If the server needs to do something special in an OS process... might as well let the OS mediate that interaction so that it can be fully generic, rather than trying to bend the language around whatever the unknown action might be.
phplovesong | 5 hours ago
ninininino | 17 minutes ago
rapnie | 6 hours ago
phplovesong | 5 hours ago
karel-3d | 8 hours ago
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
jeltz | 7 hours ago
giancarlostoro | 7 hours ago
ch4s3 | 7 hours ago
lpil | 7 hours ago
https://gleam.run/frequently-asked-questions/#How-does-Gleam...
ch4s3 | 6 hours ago
lpil | 6 hours ago
ch4s3 | 6 hours ago
> I'd say if you know and like Rust, then Gleam should be easy to pick up
And you think that:
> a Rust programmer is more likely to prefer Gleam to Elixir
Are we maybe splitting hairs here?
trenchgun | 6 hours ago
This is way too strong and narrow statement. Gleam is statically typed garbage collected language, closer to OCaml than Rust. Elixir if you like dynamically typed instead.
benzible | 5 hours ago
tasuki | 2 hours ago
josevalim | 28 minutes ago
lpil | 6 hours ago
The languages that Gleam is most like might be Standard ML, OCaml, Elm, and F#.
cweagans | 5 hours ago
That is: they aren't similar languages on a technical level, but if you know Rust, you should be able to make the jump to Gleam pretty quickly.
lpil | 5 hours ago
It can take a moment to understand that things are done quite differently in the two languages due to being so different: https://gleam.run/frequently-asked-questions/#How-does-Gleam...
bmitc | 5 hours ago
And guess which languages inspired several things in Rust.
lpil | 5 hours ago
innocentoldguy | 47 minutes ago
lpil | 43 minutes ago
bmitc | 6 hours ago
I think by sentiments like this, people mean if you know unions, records, and pattern matching then you'll more easily pick up another language that has unions, records, and pattern matching.
ch4s3 | 6 hours ago
[1] https://gleam.run/cheatsheets/gleam-for-rust-users/
lpil | 41 minutes ago
ryan-duve | 5 hours ago
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.
SoftTalker | 3 hours ago
macintux | 2 hours ago
mahboi | 2 hours ago
Edit: pure* functional
sodapopcan | an hour ago
Odd, but I believe you, lol. Elixir's list comprehensions take a `:reduce` option which makes accumulating values a bit more "familiar" and I often use over `reduce`:
Not sure if there is something like that in Erlang (or Gleam for that matter).mahboi | an hour ago
Also tbh, I don't like reduce either. I agree with that article posted on HN a while back about devs not liking reduce. Just want to insert into my list or whatever.
olexsmir | 6 hours ago
capitanazo77 | 5 hours ago
Imagine a doctor about to do surgery and opening a toy box
omnimus | 5 hours ago
atollk | 5 hours ago
hinkley | 3 hours ago
throwaway27448 | 5 hours ago
ginkogruen | 5 hours ago
hinkley | 3 hours ago
tiffanyh | 5 hours ago
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
PKop | 4 hours ago
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 | 38 minutes ago
tasuki | 2 hours ago
I was surprised to find Matt Mullenweg among the sponsors.
desireco42 | 37 minutes ago
jmcgough | 24 minutes ago
tmountain | 17 minutes ago