Commit 3ba7aa8f1b7cec073c7d8f2bc219d21f7cdc7e05 - Parc - git @ Cat's Eye Technologies

git @ Cat's Eye Technologies Parc / 3ba7aa8

Rename the combinator. Chris Pressey 2 years ago

2 changed file(s) with 5 addition(s) and 5 deletion(s). Raw diff Collapse all Expand all

+2

-2

ParcMerge.hs less more

1	1
2	2	import ParcSt2St
3	3
4		transform :: (ParseState a -> ParseState b) -> (a -> b -> c) -> ParseState a -> ParseState c
5		transform c f =
	4	merge :: (ParseState a -> ParseState b) -> (a -> b -> c) -> ParseState a -> ParseState c
	5	merge c f =
6	6	(\st ->
7	7	case st of
8	8	Failure -> Failure

+3

-3

ParcMergeDemo.hs less more

11	11
12	12	-- Grammar
13	13
14		expr0 = seq (expr1) (many (transform (seq (char '+') expr1) (\v0 v1 -> v0 + v1)))
15		expr1 = seq (expr2) (many (transform (seq (char '') expr2) (\v0 v1 -> v0 v1)))
	14	expr0 = seq (expr1) (many (merge (seq (char '+') expr1) (\v0 v1 -> v0 + v1)))
	15	expr1 = seq (expr2) (many (merge (seq (char '') expr2) (\v0 v1 -> v0 v1)))
16	16	expr2 = alt number parenthesized
17	17	parenthesized = seq (char '(') (seq expr0 (char ')'))
18	18

29	29	'9' -> Just 9
30	30	_ -> Nothing)
31	31
32		accDigit = transform digit (\v0 v1 -> v0 * 10 + v1)
	32	accDigit = merge digit (\v0 v1 -> v0 * 10 + v1)
33	33
34	34	number = seq (update $ \v -> 0) (many1 accDigit)
35	35