> If a tenth of the effort that has gone into implementing Haskell had instead gone into implementing a Haskell-equivalent embedded in CL, that effort would plausibly be competitive with actual Haskell if not superior.
It's such a wildly ridiculous claim though. It implies either
1. that the syntax of Haskell is the majority of the work, such that using a dsl would remove 90% of the effort.
2. Somehow a dsl for Haskell embedded in a lisp would be more efficient to work in, so much so that development would be an order of magnitude faster.
1 is absolute nonsense. 2 might be true in a sense. I doubt it, but even if it were, such a language would no longer be Haskell, so you'd lose out on the value you gain from it's syntax. The same is true for rust.
S-expressions are nice, but they aren't always the best way of structuring things, and if you're going to forego them to better embed another language, why constrain yourself to the lisp runtime?
You can create a DSL for a team working on a specific problem. Lisp is good at that. What I have not seen is a DSL that anyone else wants to use.
Someone builds a DSL, a small team uses it. It just has to meet the needs of that team. It doesn't have to be bulletproof or elegant. It can have all kinds of rough corners. It can take undocumented tribal knowledge to know how to use it.
The comparison to Rust is therefore almost completely misleading. It's like comparing Linux in 1992 to a commercial Linux distribution today.
Yes, that is a totally fair point. But Linux is where it is today because some people in 1992 looked at Linux in the state it was in at the time and decided that it had potential. If that hadn't happened, no one outside of a small group of hackers would ever have heard of Linux. The idea that embedding languages in CL is a bad idea is likewise a self-fulfilling prophecy.
You are absolutely right that I'm squeezing a lot of content into the word "just". But I'm not doing it in a vacuum or out of ignorance.