abort if only remaining nodes are doomed

[sbp.git] / src / edu / berkeley / sbp / GSS.java

diff --git a/src/edu/berkeley/sbp/GSS.java b/src/edu/berkeley/sbp/GSS.java
index c96ceee..3c6beac 100644 (file)
--- a/src/edu/berkeley/sbp/GSS.java
+++ b/src/edu/berkeley/sbp/GSS.java
@@ -31,6 +31,7 @@ class GSS {
         public Forest.Many finalResult;
         private PriorityQueue<Reduction> reductionQueue = new PriorityQueue<Reduction>();
 
+        Parser parser() { return parser; }
         public void addReduction(Reduction r) {
             //System.out.println("+ " + r);
             parser.spin();
@@ -61,9 +62,9 @@ class GSS {
             newNode(primordealResult, startState, true);
         }
         public Phase(Phase prev, Forest forest) throws ParseFailed, IOException {
-            this.location = input.getLocation();
+            this.prevLocation = input.getLocation();
             this.token = (Tok)input.next();
-            this.prevLocation = prev==null ? location : prev.getLocation();
+            this.location = input.getLocation();
             this.prev = prev;
             this.forest = forest;
             this.pos = prev==null ? 0 : prev.pos+1;
@@ -106,13 +107,14 @@ class GSS {
         public boolean isDone() throws ParseFailed {
             if (token != null) return false;
             if (token==null && finalResult==null)
-                ParseFailed.error("unexpected end of file", this);
+                ParseFailed.error("unexpected end of file", this, null,
+                                  getLocation().createRegion(getLocation()));
             return true;
         }
 
         public Input.Location getPrevLocation() { return prevLocation; }
         public Input.Location getLocation() { return location; }
-        public Input.Region   getRegion() { return getPrevLocation().createRegion(getLocation()); }
+        public Input.Region getRegion() { return prevLocation.createRegion(location); }
         public Input.Location getNextLocation() { return nextLocation; }
         public boolean        isFrontier() { return hash!=null; }
 
@@ -139,8 +141,23 @@ class GSS {
             }
             numNewNodes = next==null ? 0 : next.hash.size();
             viewPos = this.pos;
-            if (!good && token!=null) ParseFailed.error("unexpected character", this);
-            if (token==null && finalResult==null) ParseFailed.error("unexpected end of file", this);
+            if (!good && token!=null) {
+                String toks = token+"";
+                if (toks.length()==1 && toks.charAt(0) == edu.berkeley.sbp.chr.CharAtom.left) {
+                    ParseFailed.error("unexpected increase in indentation", this,
+                                      token, getRegionFromThisToNext());
+                } else if (toks.length()==1 && toks.charAt(0) == edu.berkeley.sbp.chr.CharAtom.right) {
+                    ParseFailed.error("unexpected decrease in indentation", this,
+                                      token, getRegionFromThisToNext());
+                } else {
+                    ParseFailed.error("unexpected character '"+ANSI.cyan(StringUtil.escapify(token+"",
+                                                                                             "\\\'\r\n"))+"'",
+                                      this, token, getRegionFromThisToNext());
+                }
+            }
+            if (token==null && finalResult==null)
+                ParseFailed.error("unexpected end of file", this, null,
+                                  getLocation().createRegion(getLocation()));
             for(Node n : hash) n.check();
         }
 
@@ -168,7 +185,7 @@ class GSS {
          */
         private boolean newNode(Result result, State state, boolean fromEmptyReduction) {
             Node p = hash.get(state, result.phase());
-            if (p != null) { p.addResult(result); return true; }
+            if (p != null) { p.addResult(result); return !state.doomed(); }
             do {
                 if (token != null && state.canShift(token)) break;
                 if (state.isAccepting()) break;
@@ -176,9 +193,9 @@ class GSS {
                 if (!state.canReduce(token)) return false;
             } while(false);
             Node n = new Node(Phase.this, result, state, fromEmptyReduction);  // ALLOC
-            for(Object s : state.also)
+            for(Object s : state.conjunctStates)
                 newNode(new Result(null, n, null), (State)s, fromEmptyReduction);
-            return true;
+            return !n.state().doomed();
         }
 
         public int toInt() { return pos+1; }