Hacker News Reader

Comment by peterhull90 | Hacker News Reader

In the mid-90s I did some playing round with something called MINDY from Carnegie Mellon. It was (IIRC) a Dylan interpreter (the acronym was 'MINDY Is Not Dylan Yet') and was very interesting both to experiment with Dylan and also to see how MINDY itself was implemented. As I remember, a cool thing about the Dylan concept was that it had a sliding scale of dynamic-ness - in other words you could start off being quite relaxed about types but, where needed, you could narrow down the types, seal generic methods etc. and the compiler would then be able to optimise better, for example by avoiding dynamic dispatch if it could prove it knew the specific method at compile time.

View on HN

Mindy was used to bootstrap Gwydion Dylan, a Dylan compiler implementation. This was the main open source Dylan implementation for quite some time until Functional Objects (which obtained the code and rights from Harlequin when they went out of the language business) open sourced their implementation which is now 'Open Dylan'.

Functional Developer (What was Harelequin Dylan) was nice. The editor would syntax highlight the code based on the optimization level. In this way you could look at a method call and see if it was inlined or not and decide whether to seal functions or classes to improve performance.

Another interesting feature was the editor was written in Dylan (using a framework called Deuce). This was emacs-like and had features like virtual sections in a buffer that could each be mapped to a different file on disk. This allowed viewing in a single editor pane the implementations of all methods of a generic function even if they crossed multiple files. This could also be edited as if it was a single file.

Thanks for your great summary. :)

Functional Developer and now Open Dylan also support debugging on Windows, have a REPL (on Windows) and many other features.

With the upcoming LLVM backend, we'll be able to bring those features to other platforms, but we'll need DUIM backends to support the user interface. That's a big part of why this call for help mentions several GUI related things.

With some luck and a lot of hard work, this will be a great year for Dylan.

Optimisation colouring was one of the Harlequin Dylan features I was most proud of having a hand in back in the day. Did anything like it ever get implemented in a more mainstream IDE?

We only implemented it for static optimisations I think (i.e. you could see at a glance how well the compiler had inferred types, resolved method calls, inlined functions, etc), but we had a lot of ideas at the time around its future application to profiling results, as well as layered, more interactive presentation.

It'd be a great addition to Light Table...

I don't know of other IDE's that use the idea. It's a pity as I used this feature a lot when using HD/FD.

Reply on news.ycombinator.com