reorganize the directories under src, and rescue the JavaScript interpreter from deprecated

src/compiler/GF/Data/Graph.hs

@@ -0,0 +1,178 @@
+----------------------------------------------------------------------
+-- |
+-- Module      : Graph
+-- Maintainer  : BB
+-- Stability   : (stable)
+-- Portability : (portable)
+--
+-- > CVS $Date: 2005/11/10 16:43:44 $ 
+-- > CVS $Author: bringert $
+-- > CVS $Revision: 1.2 $
+--
+-- A simple graph module.
+-----------------------------------------------------------------------------
+module GF.Data.Graph ( Graph(..), Node, Edge, NodeInfo
+                        , newGraph, nodes, edges
+                        , nmap, emap, newNode, newNodes, newEdge, newEdges
+                        , insertEdgeWith
+                        , removeNode, removeNodes
+                        , nodeInfo
+                        , getIncoming, getOutgoing, getNodeLabel
+                        , inDegree, outDegree
+                        , nodeLabel
+                        , edgeFrom, edgeTo, edgeLabel
+                        , reverseGraph, mergeGraphs, renameNodes
+                       ) where
+
+import GF.Data.Utilities
+
+import Data.List
+import Data.Maybe
+import Data.Map (Map)
+import qualified Data.Map as Map
+import Data.Set (Set)
+import qualified Data.Set as Set
+
+data Graph n a b = Graph [n] ![Node n a] ![Edge n b]
+		 deriving (Eq,Show)
+
+type Node n a = (n,a)
+type Edge n b = (n,n,b)
+
+type NodeInfo n a b = Map n (a, [Edge n b], [Edge n b])
+
+-- | Create a new empty graph.
+newGraph :: [n] -> Graph n a b
+newGraph ns = Graph ns [] []
+
+-- | Get all the nodes in the graph.
+nodes :: Graph n a b -> [Node n a]
+nodes (Graph _ ns _) = ns
+
+-- | Get all the edges in the graph.
+edges :: Graph n a b -> [Edge n b]
+edges (Graph _ _ es) = es
+
+-- | Map a function over the node labels.
+nmap :: (a -> c) -> Graph n a b -> Graph n c b
+nmap f (Graph c ns es) = Graph c [(n,f l) | (n,l) <- ns] es
+
+-- | Map a function over the edge labels.
+emap :: (b -> c) -> Graph n a b -> Graph n a c
+emap f (Graph c ns es) = Graph c ns [(x,y,f l) | (x,y,l) <- es]
+
+-- | Add a node to the graph.
+newNode :: a               -- ^ Node label
+        -> Graph n a b 
+        -> (Graph n a b,n) -- ^ Node graph and name of new node
+newNode l (Graph (c:cs) ns es) = (Graph cs ((c,l):ns) es, c)
+
+newNodes :: [a] -> Graph n a b -> (Graph n a b,[Node n a])
+newNodes ls g = (g', zip ns ls)
+  where (g',ns) = mapAccumL (flip newNode) g ls
+-- lazy version:
+--newNodes ls (Graph cs ns es) = (Graph cs' (ns'++ns) es, ns')
+--  where (xs,cs') = splitAt (length ls) cs
+--        ns' = zip xs ls
+
+newEdge :: Edge n b -> Graph n a b -> Graph n a b
+newEdge e (Graph c ns es) = Graph c ns (e:es)
+
+newEdges :: [Edge n b] -> Graph n a b -> Graph n a b
+newEdges es g = foldl' (flip newEdge) g es
+-- lazy version:
+-- newEdges es' (Graph c ns es) = Graph c ns (es'++es)
+
+insertEdgeWith :: Eq n => 
+                  (b -> b -> b) -> Edge n b -> Graph n a b -> Graph n a b
+insertEdgeWith f e@(x,y,l) (Graph c ns es) = Graph c ns (h es)
+  where h [] = [e]
+        h (e'@(x',y',l'):es') | x' == x && y' == y = (x',y', f l l'):es'
+                              | otherwise = e':h es'
+
+-- | Remove a node and all edges to and from that node.
+removeNode :: Ord n => n -> Graph n a b -> Graph n a b
+removeNode n = removeNodes (Set.singleton n)
+
+-- | Remove a set of nodes and all edges to and from those nodes.
+removeNodes :: Ord n => Set n -> Graph n a b -> Graph n a b
+removeNodes xs (Graph c ns es) = Graph c ns' es'
+  where 
+  keepNode n = not (Set.member n xs)
+  ns' = [ x | x@(n,_) <- ns, keepNode n ]
+  es' = [ e | e@(f,t,_) <- es, keepNode f && keepNode t ]
+
+-- | Get a map of node names to info about each node.
+nodeInfo :: Ord n => Graph n a b -> NodeInfo n a b
+nodeInfo g = Map.fromList [ (n, (x, fn inc n, fn out n)) | (n,x) <- nodes g ]
+  where 
+  inc = groupEdgesBy edgeTo g
+  out = groupEdgesBy edgeFrom g
+  fn m n = fromMaybe [] (Map.lookup n m)
+
+groupEdgesBy :: (Ord n) => (Edge n b -> n) -- ^ Gets the node to group by
+             -> Graph n a b -> Map n [Edge n b]
+groupEdgesBy f g = Map.fromListWith (++) [(f e, [e]) | e <- edges g]
+
+lookupNode :: Ord n => NodeInfo n a b -> n -> (a, [Edge n b], [Edge n b])
+lookupNode i n = fromJust $ Map.lookup n i
+
+getIncoming :: Ord n => NodeInfo n a b -> n -> [Edge n b]
+getIncoming i n = let (_,inc,_) = lookupNode i n in inc
+
+getOutgoing :: Ord n => NodeInfo n a b -> n -> [Edge n b]
+getOutgoing i n = let (_,_,out) = lookupNode i n in out
+
+inDegree :: Ord n => NodeInfo n a b -> n -> Int
+inDegree i n = length $ getIncoming i n
+
+outDegree :: Ord n => NodeInfo n a b -> n -> Int
+outDegree i n = length $ getOutgoing i n
+
+getNodeLabel :: Ord n => NodeInfo n a b -> n -> a
+getNodeLabel i n = let (l,_,_) = lookupNode i n in l
+
+nodeLabel :: Node n a -> a
+nodeLabel = snd
+
+edgeFrom :: Edge n b -> n
+edgeFrom (f,_,_) = f
+
+edgeTo :: Edge n b -> n
+edgeTo (_,t,_) = t
+
+edgeLabel :: Edge n b -> b
+edgeLabel (_,_,l) = l
+
+reverseGraph :: Graph n a b -> Graph n a b
+reverseGraph (Graph c ns es) = Graph c ns [ (t,f,l) | (f,t,l) <- es ]
+
+-- | Add the nodes from the second graph to the first graph.
+--   The nodes in the second graph will be renamed using the name 
+--   supply in the first graph.
+--   This function is more efficient when the second graph
+--   is smaller than the first.
+mergeGraphs :: Ord m => Graph n a b -> Graph m a b 
+            -> (Graph n a b, m -> n) -- ^ The new graph and a function translating
+                                      --  the old names of nodes in the second graph
+                                      --  to names in the new graph.
+mergeGraphs (Graph c ns1 es1) g2 = (Graph c' (ns2++ns1) (es2++es1), newName)
+  where 
+  (xs,c') = splitAt (length (nodes g2)) c
+  newNames = Map.fromList (zip (map fst (nodes g2)) xs)
+  newName n = fromJust $ Map.lookup n newNames
+  Graph _ ns2 es2 = renameNodes newName undefined g2
+
+-- | Rename the nodes in the graph.
+renameNodes :: (n -> m) -- ^ renaming function
+            -> [m] -- ^ infinite supply of fresh node names, to
+                   --   use when adding nodes in the future.
+            -> Graph n a b -> Graph m a b
+renameNodes newName c (Graph _ ns es) = Graph c ns' es'
+    where ns' = map' (\ (n,x) -> (newName n,x)) ns
+	  es' = map' (\ (f,t,l) -> (newName f, newName t, l)) es
+
+-- | A strict 'map'
+map' :: (a -> b) -> [a] -> [b]
+map' _ [] = []
+map' f (x:xs) = ((:) $! f x) $! map' f xs