Thoughts on Rule-Based Programming | Hacker News Reader

Thoughts on Rule-Based Programming

eblong.com

43 pointslazugod9 comments

The backward subject-verb semantics in the OO examples are typical anti-OOP straw men. It doesn't have to be Room.look() and Object.examine(), when it could simply be Player.look(Room), Player.examine(Object), Player.put(Meat, Basket), etc. Don't begin with a design pattern then write code around that poorly choosen pattern. Instead write your core logic expressions first then it becomes obvious what the structure of each object ought to be.

Prolog isn't all that weird and a pretty good language for adventure ages, see: http://www.csc.villanova.edu/~dmatusze/resources/prolog/slee... http://www.csc.villanova.edu/~dmatusze/resources/prolog/spid...

Speaking of Prolog, I often run into situations where I would love to have some semi-dialect of prolog available at runtime (ie: use regexes for simple string problems, use prologexes for simple logic problems).

Are you aware of any prolog-like languages that integrate well with other programming languages?

I don't know of any (outside of semi-toy Prologs in _On Lisp_ and PAIP), but writing a Prolog dialect designed for embedding (in a similar manner to Lua) is near the top of my list of future projects. Prolog can be really awkward for some things (most notably IO / side effects), but for certain problems, its approach is an excellent fit.

Constraint programming (often bundled with Prolog) also deserve far more attention, IMHO.

For CP, GECODE is C++, which makes it very easy to bundle /if/ you're writing in that language.

SWI-Prolog can be used embedded - but I haven't any experience with the results.

I'm reading Guido Tack's thesis now, actually, trying to get a better sense of how constraint systems are implemented.

SWI is my usual Prolog runtime, but I haven't tried running it embedded. I really like Lua's design principle of, "The language doesn't handle this particular thing well, but since it's embedded, it doesn't need to - keep the language small". A mini-Prolog could focus on what it does best, have a simple C API, and leave the rest to the surrounding language.

TuProlog (http://alice.unibo.it/xwiki/bin/view/Tuprolog/) is a lightweight Prolog engine, written in Java, that's really easy to embed in Java apps.

Thanks so much for posting this, it brings back fond memories of playing IF games as a kid (wish I still had that much free time on my hands). Saved to InstaPaper for later reading.

This sounds exactly like the semi-secret language that's been floating around in my head for months!

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