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0 pointsbunderbunder10mo ago0 comments

Kind of, except that a non-DSL API doesn't create any new syntax. Which means that you get to keep all sorts of quality-of-life tools like syntax highlighting and correctness checking in the editor, autoformatting, possibly some amount of linting, etc.

A few years ago I revisited Racket after a long hiatus, and that was maybe the biggest thing I noticed. I really don't like syntax macros as much as I did back in the day. Once I decide to use `define-syntax` I've then got to decide whether I also want to wade into dealing with also implementing a syntax colorer or an indenter as part of my #lang. And if I do decide to do that, then I've got a bunch more work, and am also probably committing to working in DrRacket (otherwise I'd rather stay in emacs) because that's the only editor that supports those features, and it just turns into a whole quagmire.

And it's arguably even worse outside of Racket, where I might have to implement a whole language server and editor plugin to accomplish the same.

Versus, if I can do what I need to do with a reasonably tidy API, then I can get those quality of life things without all the extra maintenance burden.

None of this was a big deal 20 years ago. My expectations were different back then, because I hadn't been spoiled by things like the language server protocol and everyone (finally) agreeing that autoformatting is a Good Thing.

0 comments

vidarh10mo ago

Conversely, Ruby is often seen as facilitating DSL's, but none of it changes syntax, because the syntax as-is is flexible enough that redefining methods is sufficient. But everything still abides by the same syntactical rules.

The more orthogonal or flexible the language is, the less there tends to be a distinction between redefining syntactical elements and defining functions or methods.

AnimalMuppet10mo ago

Even without the new spiffs, I still don't see the point of DSLs. From where I sit, I see exactly zero problems where I think that new syntax is what I need to be able to write a solution.

fn-mote10mo ago

I used to feel that way. I’m still not a convert, but now I’ve seen a lot more complexity papered over by a nice DSL.

Standard math syntax is a DSL. I understand math a lot more quickly than I understand the same thing written in 20 lines of code.

I think the language we use to express ourselves influence the quality of the product. If your language encapsulates complexity, then you can build more complicated things.

I’m not arguing in favor of specific (“pointless”) DSLs, but there’s a nice paper about making a video editing language in Racket [1] that makes a DSL seem pretty convincing.

[1]: https://www2.ccs.neu.edu/racket/pubs/icfp17-acf.pdf

bunderbunderOP10mo ago

The protocol buffer / grpc definition language is another great example of where a DSL can shine. Especially if you compare it to efforts to accomplish basically the same task using pre-existing languages, such as OpenAPI (JSON) and WCF (XML).

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jolt4210mo ago

Lisps don't support OO, concurrency like Go, or type checking but you can write a DSLs for them. Not useful? How about a rules engine?

kstrauser10mo ago

Lisps support OO like you wouldn’t believe: https://lispcookbook.github.io/cl-cookbook/clos.html

bunderbunderOP10mo ago

You could write DSLs for them, but you could just as easily do it within the existing syntax. Which is exactly how all the popular lisp implementations of OO, concurrency and type checking work in practice.

Many of them do use macros. But that's not about creating a special language; that's about moving expensive computations and checks that can be done statically to compile time where they belong.

BeetleB10mo ago

Any markup language is a DSL. Including HTML.

Netlists.

Makefiles.

And so on.

You really don't see the value of DSLs?

draegtun10mo ago

Except in homoiconic languages, like Rebol/Red/Lisp, there is no (need for a) new syntax.

ljlolel10mo ago

Regex

miki12321110mo ago

TBH, I feel like regexes would be much easier to understand in a more literate form with standard syntax. Something like:

  user_part = re.repeat(re.alnum | re.chars(".-_+"))
  domain_segment = re.repeat(re.alnum)
  domain = re.list(domain_segment,separator=".",minimum=2)
  email_address = user_part + "@" + domain

Where, in a real program, `domain` would be defined in a "standard library of constructions" that you can just import and re-use in more complicated regexes.

Something like this can be implemented in any language with operator overloading, no DSL required. Without operator overloading, the syntax would be a bit more awkward, but still nicer than the current regexp madness.

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AnimalMuppet10mo ago

Fair point, though I learned regexes a long time ago, so that they weren't on my "problems that I can solve with new syntax" list, but instead on the "syntax that's already there" list.

draegtun10mo ago

Or in Rebol/Red it's Parse, a dialect (DSL) that comes with the language - https://www.rebol.com/docs/core23/rebolcore-15.html

dragonwriter10mo ago

> Kind of, except that a non-DSL API doesn't create any new syntax.

Internal DSLs are always (by definition) valid code in the host language; external DSL, where parsing and interpretation or compilation to executable code for raw text code in the DSL are implemented in the host language, are all new syntax, but “languages that encourage making DSL” are usually ones that are favored for internal, not external, DSLs.

bunderbunderOP10mo ago

I think that "internal DSL" is what the grandparent poster meant by API, so I just went with that.

I think the internal/external terminology might be kind of outdated, anyway? I think this might be the first time I've encountered it in the wild in over 10 years.

dragonwriter10mo ago

> I think that "internal DSL" is what the grandparent poster meant by API, so I just went with that.

When people talk about REBOL/Red (or Ruby or Lisps) encouraging making DSLs, they are referring to internal DSLs. In Ruby, these are just APIs consisting of normal objects and methods, in Lisps they often involve macro calls, which may or may not correspond to what people mean by an API, and in REBOL/Red the design of the language is such that “normal” functions can do things that would take macros in Lisp.

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0 pointsbunderbunder10mo ago0 comments

And it's arguably even worse outside of Racket, where I might have to implement a whole language server and editor plugin to accomplish the same.

Versus, if I can do what I need to do with a reasonably tidy API, then I can get those quality of life things without all the extra maintenance burden.

0 comments

vidarh10mo ago

The more orthogonal or flexible the language is, the less there tends to be a distinction between redefining syntactical elements and defining functions or methods.

AnimalMuppet10mo ago

Even without the new spiffs, I still don't see the point of DSLs. From where I sit, I see exactly zero problems where I think that new syntax is what I need to be able to write a solution.

fn-mote10mo ago

I used to feel that way. I’m still not a convert, but now I’ve seen a lot more complexity papered over by a nice DSL.

Standard math syntax is a DSL. I understand math a lot more quickly than I understand the same thing written in 20 lines of code.

I think the language we use to express ourselves influence the quality of the product. If your language encapsulates complexity, then you can build more complicated things.

I’m not arguing in favor of specific (“pointless”) DSLs, but there’s a nice paper about making a video editing language in Racket [1] that makes a DSL seem pretty convincing.

[1]: https://www2.ccs.neu.edu/racket/pubs/icfp17-acf.pdf

bunderbunderOP10mo ago

1 more reply

jolt4210mo ago

Lisps don't support OO, concurrency like Go, or type checking but you can write a DSLs for them. Not useful? How about a rules engine?

kstrauser10mo ago

Lisps support OO like you wouldn’t believe: https://lispcookbook.github.io/cl-cookbook/clos.html

bunderbunderOP10mo ago

Many of them do use macros. But that's not about creating a special language; that's about moving expensive computations and checks that can be done statically to compile time where they belong.

BeetleB10mo ago

Any markup language is a DSL. Including HTML.

Netlists.

Makefiles.

And so on.

You really don't see the value of DSLs?

draegtun10mo ago

Except in homoiconic languages, like Rebol/Red/Lisp, there is no (need for a) new syntax.

ljlolel10mo ago

Regex

miki12321110mo ago

TBH, I feel like regexes would be much easier to understand in a more literate form with standard syntax. Something like:

  user_part = re.repeat(re.alnum | re.chars(".-_+"))
  domain_segment = re.repeat(re.alnum)
  domain = re.list(domain_segment,separator=".",minimum=2)
  email_address = user_part + "@" + domain

Where, in a real program, `domain` would be defined in a "standard library of constructions" that you can just import and re-use in more complicated regexes.

2 more replies

AnimalMuppet10mo ago

Fair point, though I learned regexes a long time ago, so that they weren't on my "problems that I can solve with new syntax" list, but instead on the "syntax that's already there" list.

draegtun10mo ago

Or in Rebol/Red it's Parse, a dialect (DSL) that comes with the language - https://www.rebol.com/docs/core23/rebolcore-15.html

dragonwriter10mo ago

> Kind of, except that a non-DSL API doesn't create any new syntax.

bunderbunderOP10mo ago

I think that "internal DSL" is what the grandparent poster meant by API, so I just went with that.

I think the internal/external terminology might be kind of outdated, anyway? I think this might be the first time I've encountered it in the wild in over 10 years.

dragonwriter10mo ago

> I think that "internal DSL" is what the grandparent poster meant by API, so I just went with that.

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