Re: Specialized input parsing for code/REPL in DrScheme?

[Paul Fernhout <pdfernhout@kurtz-fernhout.com>]

Robby-

Thanks for the improvements. This worked for me in debug MrEd. Also,
when there is a syntax error in the entered code, the first character of
the entire buffer is highlighted (before I don't think I got a
highlight). Presumably, now I can improve the example to keep updating
the error location as my reader progresses.

What's really cool about this is one could now in theory have DrScheme
host any selected language (Scheme-like or not) through an appropriate
parser and interpreter written in Scheme, and provide meaningful
location information for syntax errors, all within in the comfort of
DrScheme. One could even have the "guest" language keyword usage linked
into the HelpDesk. This could let one add parsers for Logo, interpreted
C, interpreted Forth, interpreted assembler, Python, TrueBasic, or
Smalltalk, translate the results to Scheme code for speedy evaluation,
and leverage off of the host DrScheme/MrEd runtime libraries for
graphics or networking. There still might be some issues with generating
meaningful debugging messages during interpretation if the guest
language strayed too far from Scheme though, although I get the feeling
DrScheme has some machinery related to Zodiac already in place that
might help with some of that. This could be nice in the context of a
comparative programming languages course, in the direction of Samuel
Kamin's book "Programming Languages: An Interpreter-Based Approach". It
also might increase support for maintaining the DrScheme infrastructure
if people teaching courses in other languages like Logo or Basic
migrated to using DrScheme plus an appropriate "language-pack" parser as
their cross-platform teaching environment. And from there, it is of
course a natural easy step to try Scheme for those courses.

Thanks again!

-Paul Fernhout
Kurtz-Fernhout Software 
=========================================================
Developers of custom software and educational simulations
Creators of the Garden with Insight(TM) garden simulator
http://www.kurtz-fernhout.com

Robert Bruce Findler wrote:
> 
> Apologies, this was indeed a bug in the tool that I sent you (I
> didn't read my own interfaces carefully enough!). The attached
> good-unit.ss should solve the problems you were having. It works in
> both debug and non-debug modes (and the teaching languages as well).
> 
> Hope that helps,
> Robby