News
If it seems to have gone quiet around here recently, that's only partly because it's summer, and the lure of the outdoors is stronger than staying in with my head in a chunk of code. I have been gnawing away at a major subproject: converting a real language based on yacc over to pacc. This has been quite an eye-opener! Read More...
That was almost too easy. It took just a few minutes to implement $ as new syntax to indicate feeding points (the new node type in the AST is called cafe), then update the cooker, eat a few test cases, and wash up by removing the -r option. Read More...
I thought I'd cracked it. Following Bryan Ford, I have always written my spacing at the end of “lexical” rules, with an additional call at the beginning of the start rule. For example, picking up again a slightly improved version of our trivial digit adder, and again ignoring feeding for the moment I would have written: Read More...
I've always been very proud of feeding. It solves a problem which Bryan Ford highlights in his original thesis, and as far as I know nobody else has solved this problem. (If anybody would like to award me a PhD for this, please get in touch at the usual address.) Life has taught me that ideas are cheap. To implement an idea, well, that's... Read More...
This has got out of hand. I really like the work that I've been doing, and I'm certain that I will incorporate it into pacc. But not this release. Read More...
It's so long since I've done any serious work on the parser engine that I've more or less completely forgotten how it works. So I've begun a side-project of documenting the internals. I've covered a significant amount of ground, which has refreshed my memory. (And also given me a few things to tidy up at a later date.) Read More...
I'm starting to implement what I'm calling “new-rep”. To begin with, we can gloss over the details of exactly how it will be expressed in pacc, but we will need to decide how it will look in the AST. My first test case will be the unary counting grammar, which might look a bit like this: Read More...
