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.

Regex

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.

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.

I don't quite understand where regex gets its reputation from. I think that once you remember the meaning of the operators, it's not too bad. (And the concise syntax is actually very helpful.)

I get that the meaning of the operators is not clear unless you're already familiar with regex, but neither is the meaning of !, ?, %, &, |, ^, ~, &&, ||, <<, >>, *, //, &, ++ (prefix), ++ (postfix), and so on. You learn these because you need them once, and then they're burned into your mind forever. Regex was similar for me.

I think regex gets some of its hate from people writing painfully complex matchers. 99% of my day to day regex use is simpler string searches on the command line or in my editor. I’m really happy I took the time to learn the syntax (spent about a week on it around 15 years ago) because now it doesn’t get in my way.

Also, regexps are just that: regular. You can mostly read them from left to right decoding each symbol at a time.

The limitation with regex is that's it's context free, whereas a regular grammar is simpler and more powerful IMO.

Regex syntax helps you understand what a regex does, not necessarily why it does it.

You can't decompose it into parts, you can't give those parts human-friendly names, you can't re-use parts in other regexes, you can't (easily) write functions that return or manipulate regexes (like that "list with separator" function shown above).

recommend you check out raku Grammars … https://docs.raku.org/language/grammars

Or in Red's case, Parse - https://www.red-lang.org/2013/11/041-introducing-parse.html

There’s really nothing about this that couldn’t be expressed just as clearly in a more general API though, even in C, IMO. Building it into the syntax is a little weird to me.

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

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

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).

Captain Pedant here, but OpenAPI also accepts yaml which suffers from a ton less { and "

gRPC and I are not friends and I've thankfully never needed to interact with WCF

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

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?

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

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.

Any markup language is a DSL. Including HTML.

Netlists.

Makefiles.

And so on.

You really don't see the value of DSLs?

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.

> 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.

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.

> 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.