From ca5b62a4099a7891f23d7d20dec05207b7d4ab06 Mon Sep 17 00:00:00 2001
From: Jed Barber <jjbarber@y7mail.com>
Date: Sun, 7 Dec 2014 19:48:48 +1100
Subject: del instruction added

---
 src/Grasp/Interpreter.hs | 17 ++++++++++++++++-
 src/Grasp/Monad.hs       | 41 +++++++++++++++++++++++++++++++++++++++--
 2 files changed, 55 insertions(+), 3 deletions(-)

diff --git a/src/Grasp/Interpreter.hs b/src/Grasp/Interpreter.hs
index 0d24ce1..bca167a 100644
--- a/src/Grasp/Interpreter.hs
+++ b/src/Grasp/Interpreter.hs
@@ -112,7 +112,22 @@ newI = do
 
 
 delI :: GraspM ()
-delI = GMonad.updateIP
+delI = do
+    curNode <- GMonad.peekIP >>= return . Maybe.fromJust
+
+    tailNodes <- GMonad.nodesOut (EL.mk "tail") curNode
+    headNodes <- GMonad.nodesOut (EL.mk "head") curNode
+    labelNodes <- GMonad.nodesOut (EL.mk "label") curNode
+
+    Monad.when (length tailNodes /= 0) (do
+        input <- mapM GMonad.edgesOut tailNodes >>= return . concat
+        let labels = map (EL.mk . IN.toString . GN.toInst) labelNodes
+            heads = map GN.toNode headNodes
+            result = filter (\x -> (length headNodes == 0 || GE.toDest x `elem` heads) &&
+                                    (length labelNodes == 0 || GE.toLabel x `elem` labels)) input
+        GMonad.delEdges result )
+
+    GMonad.updateIP
 
 
 
diff --git a/src/Grasp/Monad.hs b/src/Grasp/Monad.hs
index e58aa74..ba500af 100644
--- a/src/Grasp/Monad.hs
+++ b/src/Grasp/Monad.hs
@@ -13,9 +13,10 @@ module Grasp.Monad (
     peekIP,
     nextIP,
 
-    nodesOut,
+    nodesOut, edgesOut,
     reLabel,
-    insEdge
+    insEdge, insEdges,
+    delEdge, delEdges
     ) where
 
 
@@ -313,6 +314,18 @@ nodesOut s n = do
 
 
 
+edgesOut :: GNode -> GraspM [GEdge]
+edgesOut n = do
+    (gr, ips, fh) <- State.get
+    curNode <- peekIP
+
+    let eout = Graph.out gr (GN.toNode (Maybe.fromJust curNode))
+        result = map GE.mk eout
+
+    if (Maybe.isNothing curNode) then return [] else return result
+
+
+
 reLabel :: Instruction -> GNode -> GraspM ()
 reLabel i n = do
     (gr, ips, fh) <- State.get
@@ -331,3 +344,27 @@ insEdge e = do
     let gr' = Graph.insEdge (GE.toLEdge e) gr
     State.put (gr', ips, fh)
 
+
+
+insEdges :: [GEdge] -> GraspM ()
+insEdges es = do
+    (gr, ips, fh) <- State.get
+    let gr' = Graph.insEdges (map GE.toLEdge es) gr
+    State.put (gr', ips, fh)
+
+
+
+delEdge :: GEdge -> GraspM ()
+delEdge e = do
+    (gr, ips, fh) <- State.get
+    let gr' = Graph.delLEdge (GE.toLEdge e) gr
+    State.put (gr', ips, fh)
+
+
+
+delEdges :: [GEdge] -> GraspM ()
+delEdges es = do
+    (gr, ips, fh) <- State.get
+    let gr' = List.foldl' (flip Graph.delLEdge) gr (map GE.toLEdge es)
+    State.put (gr', ips, fh)
+
-- 
cgit