#236: Keep track of the last iterable instead of the last iteration a…

…nd count the iterations of the iterable afterwards.

core/src/main/java/io/parsingdata/metal/expression/value/reference/CurrentIteration.java

@@ -46,20 +46,21 @@ public class CurrentIteration implements ValueExpression {
 
     @Override
     public ImmutableList<Optional<Value>> eval(final ParseState parseState, final Encoding encoding) {
-        final BigInteger currentIndex = findCurrentIteration(parseState.order, ZERO).computeResult();
-        return ImmutableList.create(Optional.of(createFromNumeric(currentIndex, new Encoding())));
+        final ParseGraph iterable = findIterable(parseState.order, ParseGraph.EMPTY).computeResult();
+        final BigInteger iteration = countIterable(iterable, ZERO).computeResult().max(ZERO);
+        return ImmutableList.create(Optional.of(createFromNumeric(iteration, new Encoding())));
     }
 
-    private Trampoline<BigInteger> findCurrentIteration(final ParseItem item, final BigInteger currentIndex) {
-        if (!item.isGraph()) { return complete(() -> currentIndex); }
+    private Trampoline<ParseGraph> findIterable(final ParseItem item, final ParseGraph iterableCandidate) {
+        if (!item.isGraph()) { return complete(() -> iterableCandidate); }
         if (item.getDefinition().isIterable()) {
-            return intermediate(() -> findCurrentIteration(item.asGraph().head, countIterables(item.asGraph(), ZERO).computeResult()));
+            return intermediate(() -> findIterable(item.asGraph().head, item.asGraph()));
         }
-        return intermediate(() -> findCurrentIteration(item.asGraph().head, currentIndex));
+        return intermediate(() -> findIterable(item.asGraph().head, iterableCandidate));
     }
 
-    private Trampoline<BigInteger> countIterables(final ParseGraph graph, final BigInteger count) {
-        if (!graph.isEmpty()) { return intermediate(() -> countIterables(graph.tail, count.add(ONE))); }
+    private Trampoline<BigInteger> countIterable(final ParseGraph graph, final BigInteger count) {
+        if (!graph.isEmpty()) { return intermediate(() -> countIterable(graph.tail, count.add(ONE))); }
         return complete(() -> count.subtract(ONE));
     }