On Monday, 14 January 2019 at 05:31:27 UTC, Paul Backus wrote:
Scheme is probably the language that takes this idea of a minimal "core language" with powerful metaprogramming facilities the furthest, and the result is a fragmented ecosystem that makes writing portable, non-trivial programs close to impossible. (See "The Lisp Curse" [1].)
Much as I hate to disagree with folks on the internet, this is an explanation in search of an example. Scheme was originally created as a toy language so Steele and Sussman could have an object oriented language with actors.[1] It later turned out to be a good language for SICP. Macros did not even appear in the Scheme standard until R4RS, and they were not part of the standard until R5RS in 1998, 23 years after initial work started on Scheme. That's not to say that individual implementations didn't have Common Lisp macros prior to R5RS, but the metaprogramming thing was more of a Common Lisp thing than a Scheme thing.
To me, it's obvious why Scheme has never taken off. It wasn't created as a language for widespread commercial usage. That was the realm of Common Lisp, and to some extent Common Lisp succeeded. CL was not killed by excessive use of macros.
I'll also note that R started as a dialect of Scheme, but it was designed for practical use from the start, and it has millions of users. D has little hope of ever achieving the popularity of R. You can do all kinds of metaprogramming with R. I got tired of R's lack of proper tail call support, so added a working implementation of Clojure's recur in a couple of hours.
Extrapolating from Scheme to D is simply not the best use of one's time.
[1] See page 33 of https://dreamsongs.com/Files/HOPL2-Uncut.pdf
