Commit a0e541ccf5405c908723a90968c093f9b9bfe127 - Fountain

Implement <, >, and add example showing why locals would be nice. Chris Pressey 1 year, 10 months ago

6 changed file(s) with 48 addition(s) and 3 deletion(s). Raw diff Collapse all Expand all

-0

README.md less more

73	73
74	74	### Semantics
75	75
	76	* Inc, dec, gt, lt, should take either a variable or an integer on the RHS.
	77	Really, the RHS could be some kind of simple expression probably.
76	78	* Require that variables be declared. (Unless maybe operating in some cavalier mode)
77	79	* Check constraints on all branches of an alternation.
78	80	* Allow local variables to be declared.

-0

eg/spaced.fountain less more

	0	Goal ::= ShortSentence;
	1	ShortSentence ::= "Hi" Sp "there" "!";
	2	LongSentence ::=
	3	"The" Sp "quick" Sp "brown" Sp "fox" Sp
	4	"jumped" Sp "over" Sp "the" Sp "lazy" Sp "dog" "."
	5	;
	6	Sp ::= <. n = 0 .> { " " <. n += 1 .> } <. n > 0 .>;

-2

src/Language/Fountain/Constraint.hs less more

8	8	\| Arb Variable
9	9	\| Inc Variable Integer
10	10	\| Dec Variable Integer
11		\| GT Variable Integer
12		\| LT Variable Integer
	11	\| GreaterThan Variable Integer
	12	\| LessThan Variable Integer
13	13	deriving (Show, Ord, Eq)

+12

-0

src/Language/Fountain/Generator.hs less more

91	91	Just $ update (\i -> Just (i + 1)) v st
92	92	applyConstraint (Dec v i) st =
93	93	Just $ update (\i -> Just (i - 1)) v st
	94	applyConstraint (GreaterThan v i) st =
	95	case fetch v st of
	96	Just value ->
	97	if value > i then Just st else Nothing
	98	Nothing ->
	99	Nothing
	100	applyConstraint (LessThan v i) st =
	101	case fetch v st of
	102	Just value ->
	103	if value < i then Just st else Nothing
	104	Nothing ->
	105	Nothing
94	106
95	107
96	108	constructState :: [String] -> GenState

+13

-1

src/Language/Fountain/Loader.hs less more

45	45	keyword ".>"
46	46	return $ Constraint $ c
47	47
48		constrainer = (try arb) <\|> (try unifyConst) <\|> (try unifyVar) <\|> (try inc) <\|> (try dec) -- <\|> (try gt) <\|> (try lt)
	48	constrainer = (try arb) <\|> (try unifyConst) <\|> (try unifyVar) <\|> (try inc) <\|> (try dec) <\|> (try gt) <\|> (try lt)
49	49
50	50	arb = do
51	51	keyword "arb"

75	75	keyword "-="
76	76	n <- intlit
77	77	return $ Dec v n
	78
	79	gt = do
	80	v <- variable
	81	keyword ">"
	82	n <- intlit
	83	return $ GreaterThan v n
	84
	85	lt = do
	86	v <- variable
	87	keyword "<"
	88	n <- intlit
	89	return $ LessThan v n
78	90
79	91	variable = do
80	92	s <- lowWord

+12

-0

src/Language/Fountain/Parser.hs less more

73	73	Just $ update (\i -> Just (i + 1)) v st
74	74	applyConstraint (Dec v i) st =
75	75	Just $ update (\i -> Just (i - 1)) v st
	76	applyConstraint (GreaterThan v i) st =
	77	case fetch v st of
	78	Just value ->
	79	if value > i then Just st else Nothing
	80	Nothing ->
	81	Nothing
	82	applyConstraint (LessThan v i) st =
	83	case fetch v st of
	84	Just value ->
	85	if value < i then Just st else Nothing
	86	Nothing ->
	87	Nothing
76	88
77	89
78	90	parseFrom :: Grammar -> String -> ParseState