Language-oriented programming

Oddly, following the Wikipedia list of different programming paradigms to "language-oriented programming" led me right back to MPS, and a raft of fascinating articles by Martin Fowler about the notion of a "language workbench". [Here], [here], and [here].

Chief among the things that people seem iffy about in LOP is the idea that the stored representation is in fact no longer text (and what that does to version control) - but you know what? Decl is probably an ideal representation language for a DSL-oriented approach (one of the things I was struggling towards in the first iteration) and is entirely text-based.

So that begs further exploration.

Eco

Holier Toledo! Eco is a text editor that parses arbitrary languages on the fly and allows you to insert "language boxes" to embed other languages within them. The data structure actually saved is the composite parse tree, not the text, which is mildly alarming given the reliance of the existing programming infrastructure on text source code (although Laurence Tratt, the editor's promulgator, notes that Smalltalk has solved many of these problems).

This is really quite attractive. I can't think of a good reason it couldn't be duplicated in something along the lines of Padre, using Marpa.

JetBrains MPS

Holy Toledo - this is amazing! It's an editor/DSL integrated environment that allows you to compose your own DSLs into code in the editor, then autogenerate the output language when needed - through multiple levels of abstraction if necessary. Just watching the demo screencasts is making me smarter.

Anyway, this is kind of what I want to do, except, like the emperor in Amadeus, I find there are "too many notes". I need more simplicity. Maybe. Although damn. It sure is pretty. There's one embedded decision table - right in the C code - that gets translated into a C-like language with a "gswitch" statement and then further into straight C. That is tasty.

I probably ought to look at Haskell

Haskell seems like it's maybe not 100% ready for prime time as a production language through the whole stack [previously], but the Haskell community is looking at some really, really neat stuff.  (Quite aside from factorization diagrams.)

Case in point, and discovered while writing about factorization diagrams: embedded domain-specific languages.  (Like their Workflow module.)

Infunl query language for clickpaths

This is really, really neat. (examples here) I want to see more of this kind of thing.