Commit d4457d2e0cee2baeee5740b72567e86e608fbd4d - Parc

Mention ordered vs. non-deterministic choice. Chris Pressey 5 months ago

1 changed file(s) with 7 addition(s) and 1 deletion(s). Raw diff Collapse all Expand all

-1

README.md less more

15	15	Generally, you want to do more with the input string than say whether it
16	16	is or is not in the language, yes? So, there are more extended
17	17	versions here too.
	18
	19	(Before getting to the extended versions, I want to highlight one thing,
	20	which is that the choice operator in Parc is _ordered choice_, as used in
	21	e.g. PEG parsers. This is arguably less mathematically nice than
	22	the _non-deterministic choice_ used in e.g. context-free grammars,
	23	but it is unarguably simpler to implement.)
18	24
19	25	### `ParcSt`
20	26

59	65	with an extra combinator. We can't build this combinator out of existing
60	66	combinators; it needs to access the parse state directly. Also, its
61	67	definition turns out to be somewhat more complicated. So, this is where
62		we start leaving "fits on a page" territory
	68	we start leaving "fits on a page" territory.
63	69
64	70	The [`ParcMerge.hs`](ParcMerge.hs) module extends `ParcSt2St.hs` with a
65	71	combinator called `merge`. `merge` takes a parser P and a function F which