mirror of
https://github.com/GrammaticalFramework/gf-core.git
synced 2026-04-09 04:59:31 -06:00
Parametrized the type of FAs over the state type.
This commit is contained in:
@@ -5,9 +5,9 @@
|
||||
-- Stability : (stable)
|
||||
-- Portability : (portable)
|
||||
--
|
||||
-- > CVS $Date: 2005/09/14 15:17:29 $
|
||||
-- > CVS $Date: 2005/09/14 16:08:35 $
|
||||
-- > CVS $Author: bringert $
|
||||
-- > CVS $Revision: 1.3 $
|
||||
-- > CVS $Revision: 1.4 $
|
||||
--
|
||||
-- Approximates CFGs with finite state networks.
|
||||
-----------------------------------------------------------------------------
|
||||
@@ -27,7 +27,7 @@ import GF.Speech.FiniteState
|
||||
import GF.Speech.TransformCFG
|
||||
|
||||
cfgToFA :: Ident -- ^ Grammar name
|
||||
-> Options -> CGrammar -> FA () (Maybe String)
|
||||
-> Options -> CGrammar -> NFA String
|
||||
cfgToFA name opts = minimize . compileAutomaton start . makeSimpleRegular
|
||||
where start = getStartCat opts
|
||||
|
||||
@@ -67,7 +67,7 @@ mutRecCats incAll g = equivalenceClasses $ symmetricSubrelation $ transitiveClos
|
||||
-- Convert a strongly regular grammar to a finite automaton.
|
||||
compileAutomaton :: Cat_ -- ^ Start category
|
||||
-> CFRules
|
||||
-> FA () (Maybe Token)
|
||||
-> NFA Token
|
||||
compileAutomaton start g = make_fa s [Cat start] f fa''
|
||||
where fa = newFA ()
|
||||
s = startState fa
|
||||
@@ -77,7 +77,7 @@ compileAutomaton start g = make_fa s [Cat start] f fa''
|
||||
-- | The make_fa algorithm from \"Regular approximation of CFLs: a grammatical view\",
|
||||
-- Mark-Jan Nederhof. International Workshop on Parsing Technologies, 1997.
|
||||
make_fa :: State -> [Symbol Cat_ Token] -> State
|
||||
-> FA () (Maybe Token) -> FA () (Maybe Token)
|
||||
-> NFA Token -> NFA Token
|
||||
make_fa q0 alpha q1 fa =
|
||||
case alpha of
|
||||
[] -> newTransition q0 q1 Nothing fa
|
||||
|
||||
@@ -5,13 +5,13 @@
|
||||
-- Stability : (stable)
|
||||
-- Portability : (portable)
|
||||
--
|
||||
-- > CVS $Date: 2005/09/14 15:29:53 $
|
||||
-- > CVS $Date: 2005/09/14 16:08:35 $
|
||||
-- > CVS $Author: bringert $
|
||||
-- > CVS $Revision: 1.8 $
|
||||
-- > CVS $Revision: 1.9 $
|
||||
--
|
||||
-- A simple finite state network module.
|
||||
-----------------------------------------------------------------------------
|
||||
module GF.Speech.FiniteState (FA, State,
|
||||
module GF.Speech.FiniteState (FA, State, NFA, DFA,
|
||||
startState, finalStates,
|
||||
states, transitions,
|
||||
newFA,
|
||||
@@ -22,71 +22,106 @@ module GF.Speech.FiniteState (FA, State,
|
||||
prFAGraphviz) where
|
||||
|
||||
import Data.List
|
||||
import Data.Maybe (fromJust)
|
||||
import Data.Maybe (catMaybes,fromJust)
|
||||
|
||||
import GF.Data.Utilities
|
||||
import qualified GF.Visualization.Graphviz as Dot
|
||||
|
||||
type State = Int
|
||||
|
||||
data FA a b = FA (Graph State a b) State [State]
|
||||
data FA n a b = FA (Graph n a b) n [n]
|
||||
|
||||
type State = Node
|
||||
type NFA a = FA State () (Maybe a)
|
||||
|
||||
startState :: FA a b -> State
|
||||
type DFA a = FA [State] () a
|
||||
|
||||
|
||||
startState :: FA n a b -> n
|
||||
startState (FA _ s _) = s
|
||||
|
||||
finalStates :: FA a b -> [State]
|
||||
finalStates :: FA n a b -> [n]
|
||||
finalStates (FA _ _ ss) = ss
|
||||
|
||||
states :: FA a b -> [(State,a)]
|
||||
states :: FA n a b -> [(n,a)]
|
||||
states (FA g _ _) = nodes g
|
||||
|
||||
transitions :: FA a b -> [(State,State,b)]
|
||||
transitions :: FA n a b -> [(n,n,b)]
|
||||
transitions (FA g _ _) = edges g
|
||||
|
||||
newFA :: a -- ^ Start node label
|
||||
-> FA a b
|
||||
newFA :: Enum n => a -- ^ Start node label
|
||||
-> FA n a b
|
||||
newFA l = FA g s []
|
||||
where (g,s) = newNode l (newGraph [0..])
|
||||
where (g,s) = newNode l (newGraph [toEnum 0..])
|
||||
|
||||
addFinalState :: State -> FA a b -> FA a b
|
||||
addFinalState :: n -> FA n a b -> FA n a b
|
||||
addFinalState f (FA g s ss) = FA g s (f:ss)
|
||||
|
||||
newState :: a -> FA a b -> (FA a b, State)
|
||||
newState :: a -> FA n a b -> (FA n a b, n)
|
||||
newState x (FA g s ss) = (FA g' s ss, n)
|
||||
where (g',n) = newNode x g
|
||||
|
||||
newTransition :: State -> State -> b -> FA a b -> FA a b
|
||||
newTransition :: n -> n -> b -> FA n a b -> FA n a b
|
||||
newTransition f t l = onGraph (newEdge f t l)
|
||||
|
||||
mapStates :: (a -> c) -> FA a b -> FA c b
|
||||
mapStates :: (a -> c) -> FA n a b -> FA n c b
|
||||
mapStates f = onGraph (nmap f)
|
||||
|
||||
mapTransitions :: (b -> c) -> FA a b -> FA a c
|
||||
mapTransitions :: (b -> c) -> FA n a b -> FA n a c
|
||||
mapTransitions f = onGraph (emap f)
|
||||
|
||||
minimize :: FA () (Maybe a) -> FA () (Maybe a)
|
||||
minimize = onGraph mimimizeGr1
|
||||
minimize :: NFA a -> NFA a
|
||||
minimize = onGraph id
|
||||
|
||||
onGraph :: (Graph State a b -> Graph State c d) -> FA a b -> FA c d
|
||||
onGraph :: (Graph n a b -> Graph n c d) -> FA n a b -> FA n c d
|
||||
onGraph f (FA g s ss) = FA (f g) s ss
|
||||
|
||||
-- | Transform a standard finite automaton with labelled edges
|
||||
-- to one where the labels are on the nodes instead. This can add
|
||||
-- up to one extra node per edge.
|
||||
moveLabelsToNodes :: Eq a => FA () (Maybe a) -> FA (Maybe a) ()
|
||||
moveLabelsToNodes :: (Ord n,Eq a) => FA n () (Maybe a) -> FA n (Maybe a) ()
|
||||
moveLabelsToNodes = onGraph moveLabelsToNodes_
|
||||
where moveLabelsToNodes_ gr@(Graph c _ _) = Graph c' (zip ns ls) (concat ess)
|
||||
where is = incoming gr
|
||||
(c',is') = mapAccumL fixIncoming c is
|
||||
(ns,ls,ess) = unzip3 (concat is')
|
||||
|
||||
prFAGraphviz :: FA String String -> String
|
||||
prFAGraphviz = Dot.prGraphviz . mkGraphviz
|
||||
where
|
||||
mkGraphviz (FA (Graph _ ns es) s f) = Dot.Graph Dot.Directed [] (map mkNode ns) (map mkEdge es)
|
||||
fixIncoming :: (Eq n, Eq a) => [n] -> (n,(),[(n,n,Maybe a)]) -> ([n],[(n,Maybe a,[(n,n,())])])
|
||||
fixIncoming cs c@(n,(),es) = (cs'', (n,Nothing,es'):newContexts)
|
||||
where ls = nub $ map getLabel es
|
||||
(cs',cs'') = splitAt (length ls) cs
|
||||
newNodes = zip cs' ls
|
||||
es' = [ (x,n,()) | x <- map fst newNodes ]
|
||||
-- separate cyclic and non-cyclic edges
|
||||
(cyc,ncyc) = partition (\ (f,_,_) -> f == n) es
|
||||
-- keep all incoming non-cyclic edges with the right label
|
||||
to x l = [ (f,x,()) | (f,_,l') <- ncyc, l == l']
|
||||
-- for each cyclic edge with the right label,
|
||||
-- add an edge from each of the new nodes (including this one)
|
||||
++ [ (y,x,()) | (f,_,l') <- cyc, l == l', (y,_) <- newNodes]
|
||||
newContexts = [ (x, l, to x l) | (x,l) <- newNodes ]
|
||||
|
||||
alphabet :: Eq b => Graph n a (Maybe b) -> [b]
|
||||
alphabet = nub . catMaybes . map getLabel . edges
|
||||
|
||||
reachable :: (Eq b, Eq n) => Graph n a (Maybe b) -> n -> b -> [n]
|
||||
reachable = undefined
|
||||
|
||||
determinize :: NFA a -> DFA a
|
||||
determinize (FA g s f) = undefined
|
||||
|
||||
|
||||
prFAGraphviz :: (Eq n,Show n) => FA n String String -> String
|
||||
prFAGraphviz = Dot.prGraphviz . toGraphviz
|
||||
|
||||
toGraphviz :: (Eq n,Show n) => FA n String String -> Dot.Graph
|
||||
toGraphviz (FA (Graph _ ns es) s f) = Dot.Graph Dot.Directed [] (map mkNode ns) (map mkEdge es)
|
||||
where mkNode (n,l) = Dot.Node (show n) attrs
|
||||
where attrs = [("label",l)]
|
||||
++ if n == s then [("shape","box")] else []
|
||||
++ if n `elem` f then [("style","bold")] else []
|
||||
mkEdge (x,y,l) = Dot.Edge (show x) (show y) [("label",l)]
|
||||
|
||||
|
||||
--
|
||||
-- * Graphs
|
||||
--
|
||||
@@ -94,8 +129,6 @@ prFAGraphviz = Dot.prGraphviz . mkGraphviz
|
||||
data Graph n a b = Graph [n] [(n,a)] [(n,n,b)]
|
||||
deriving (Eq,Show)
|
||||
|
||||
type Node = Int
|
||||
|
||||
newGraph :: [n] -> Graph n a b
|
||||
newGraph ns = Graph ns [] []
|
||||
|
||||
@@ -124,43 +157,9 @@ incoming (Graph _ ns es) = snd $ mapAccumL f (sortBy compareDest es) (sortBy com
|
||||
compareFst p1 p2 = compare (fst p1) (fst p2)
|
||||
f es' (n,l) = let (nes,es'') = span (destIs n) es' in (es'',(n,l,nes))
|
||||
|
||||
moveLabelsToNodes_ :: (Ord n, Eq a) => Graph n () (Maybe a) -> Graph n (Maybe a) ()
|
||||
moveLabelsToNodes_ gr@(Graph c _ _) = mimimizeGr2 $ Graph c' (zip ns ls) (concat ess)
|
||||
where is = incoming gr
|
||||
(c',is') = mapAccumL fixIncoming c is
|
||||
(ns,ls,ess) = unzip3 (concat is')
|
||||
|
||||
fixIncoming :: (Eq n, Eq a) => [n] -> (n,(),[(n,n,Maybe a)]) -> ([n],[(n,Maybe a,[(n,n,())])])
|
||||
fixIncoming cs c@(n,(),es) = (cs'', (n,Nothing,es'):newContexts)
|
||||
where ls = nub $ map getLabel es
|
||||
(cs',cs'') = splitAt (length ls) cs
|
||||
newNodes = zip cs' ls
|
||||
es' = [ (x,n,()) | x <- map fst newNodes ]
|
||||
-- separate cyclic and non-cyclic edges
|
||||
(cyc,ncyc) = partition (\ (f,_,_) -> f == n) es
|
||||
-- keep all incoming non-cyclic edges with the right label
|
||||
to x l = [ (f,x,()) | (f,_,l') <- ncyc, l == l']
|
||||
-- for each cyclic edge with the right label,
|
||||
-- add an edge from each of the new nodes (including this one)
|
||||
++ [ (y,x,()) | (f,_,l') <- cyc, l == l', (y,_) <- newNodes]
|
||||
newContexts = [ (x, l, to x l) | (x,l) <- newNodes ]
|
||||
|
||||
getLabel :: (n,n,b) -> b
|
||||
getLabel (_,_,l) = l
|
||||
|
||||
mimimizeGr1 :: Eq n => Graph n () (Maybe a) -> Graph n () (Maybe a)
|
||||
mimimizeGr1 = removeEmptyLoops1
|
||||
|
||||
removeEmptyLoops1 :: Eq n => Graph n () (Maybe a) -> Graph n () (Maybe a)
|
||||
removeEmptyLoops1 (Graph c ns es) = Graph c ns (filter (not . isEmptyLoop) es)
|
||||
where isEmptyLoop (f,t,Nothing) | f == t = True
|
||||
isEmptyLoop _ = False
|
||||
|
||||
mimimizeGr2 :: Graph n (Maybe a) () -> Graph n (Maybe a) ()
|
||||
mimimizeGr2 = id
|
||||
|
||||
removeDuplicateEdges :: (Eq n, Ord b) => Graph n a b -> Graph n a b
|
||||
removeDuplicateEdges (Graph c ns es) = Graph c ns (nub es)
|
||||
|
||||
reverseGraph :: Graph n a b -> Graph n a b
|
||||
reverseGraph (Graph c ns es) = Graph c ns [ (t,f,l) | (f,t,l) <- es ]
|
||||
|
||||
|
||||
@@ -5,9 +5,9 @@
|
||||
-- Stability : (stable)
|
||||
-- Portability : (portable)
|
||||
--
|
||||
-- > CVS $Date: 2005/09/14 15:17:30 $
|
||||
-- > CVS $Date: 2005/09/14 16:08:35 $
|
||||
-- > CVS $Author: bringert $
|
||||
-- > CVS $Revision: 1.9 $
|
||||
-- > CVS $Revision: 1.10 $
|
||||
--
|
||||
-- This module converts a CFG to an SLF finite-state network
|
||||
-- for use with the ATK recognizer. The SLF format is described
|
||||
@@ -71,7 +71,7 @@ regularPrinter = prCFRules . makeSimpleRegular
|
||||
join g = concat . intersperse g
|
||||
showRhs = unwords . map (symbol id show)
|
||||
|
||||
automatonToSLF :: FA (Maybe String) () -> SLF
|
||||
automatonToSLF :: FA State (Maybe String) () -> SLF
|
||||
automatonToSLF fa =
|
||||
SLF { slfNodes = map mkSLFNode (states fa),
|
||||
slfEdges = zipWith mkSLFEdge [0..] (transitions fa) }
|
||||
|
||||
Reference in New Issue
Block a user