9f4c82cf36
function that does the adaptation for optional location information (is optional location information even worth it, or should we just default to `()`)?
LALRPop
LALRPop is a parser generator framework. Despite its name, it does not implement the LALR(1) algorithm, but rather LR(1). In fact, it has grand ambitions of eventually supporting all manner of parser generation algorithms (including more general variants like LL(*), GLR, etc), but those may or may not ever come to fruitition. :)
LALRPop has usability as a primary goal. You should be able to write compact, DRY, readable grammars. You shouldn't have to stres about writing action code or types if you don't want to. To this end, LALRPop has a number of nifty features:
- Macros that let you extract common parts of your grammar. This
means you can go beyond simple repetition like
Id*and define things likeComma<Id>for a comma-separated list of identifiers. - Macros can also create subsets, so that you easily do something
like
Expr<"all">to represent the full range of expressions, butExpr<"if">to represent the subset of expressions that can appear in anifexpression. - Compact defaults so that you can avoid writing action code much of the time.
- Type inference so you can often omit the types of nonterminals etc.
To be clear, LALRPop is barely functional. It's kind of spare time project. But it's coming along pretty quickly, now that a lot of the tricky stuff is out of the way. I'll update this README more with better instructions soon.