Iterator: new function Count()

data-cursor.go

@@ -13,25 +13,25 @@ type dataCursor struct {
 	ds        map[string]Functor
 	ctx       ExprContext
 	index     int
+	count     int
 	current   any
 	lastErr   error
 	resource  any
 	nextFunc  Functor
 	cleanFunc Functor
 	resetFunc Functor
-//	currentFunc Functor
 }
 
 func NewDataCursor(ctx ExprContext, ds map[string]Functor, resource any) (dc *dataCursor) {
 	dc = &dataCursor{
 		ds:       ds,
 		index:    -1,
+		count:    0,
 		current:  nil,
 		lastErr:  nil,
 		resource: resource,
 		ctx:      ctx.Clone(),
 		nextFunc: ds[NextName],
-//		currentFunc: ds[CurrentName],
 		cleanFunc: ds[CleanName],
 		resetFunc: ds[ResetName],
 	}
@@ -109,6 +109,7 @@ func (dc *dataCursor) Reset() (success bool, err error) {
 			ctx := cloneContext(dc.ctx)
 			if _, err = dc.resetFunc.Invoke(ctx, ResetName, []any{dc.resource}); err == nil {
 				dc.index = -1
+				dc.count = 0
 			}
 			exportObjects(dc.ctx, ctx)
 			dc.Next()
@@ -167,7 +168,6 @@ func (dc *dataCursor) mapItem(mapper Functor, item any) (mappedItem any, err err
 }
 
 func (dc *dataCursor) Next() (current any, err error) { // must return io.EOF after the last item
-	var accepted bool
 	if err = dc.lastErr; err != nil {
 		return
 	}
@@ -183,11 +183,15 @@ func (dc *dataCursor) Next() (current any, err error) { // must return io.EOF af
 				if item == nil {
 					dc.lastErr = io.EOF
 				} else {
+					accepted := true
 					if filter != nil {
 						if accepted, dc.lastErr = dc.checkFilter(filter, item); dc.lastErr != nil || !accepted {
 							item = nil
 						}
 					}
+					if accepted {
+						dc.count++
+					}
 					if item != nil && mapper != nil {
 						item, dc.lastErr = dc.mapItem(mapper, item)
 					}
@@ -197,6 +201,7 @@ func (dc *dataCursor) Next() (current any, err error) { // must return io.EOF af
 		}
 		dc.current = item
 		if dc.lastErr != nil {
+			dc.index--
 			dc.Clean()
 		}
 	} else {
@@ -206,5 +211,10 @@ func (dc *dataCursor) Next() (current any, err error) { // must return io.EOF af
 }
 
 func (dc *dataCursor) Index() int {
-	return dc.index-1
+	return dc.index - 1
+}
+
+
+func (dc *dataCursor) Count() int {
+	return dc.count
 }

iterator.go

@@ -28,6 +28,7 @@ type Iterator interface {
 	Next() (item any, err error) // must return io.EOF after the last item
 	Current() (item any, err error)
 	Index() int
+	Count() int
 }
 
 type ExtIterator interface {

list-iterator.go

@@ -143,7 +143,12 @@ func (it *ListIterator) Index() int {
 	return it.index
 }
 
+func (it *ListIterator) Count() int {
+	return it.count
+}
+
 func (it *ListIterator) Reset() (bool, error) {
 	it.index = it.start - it.step
+	it.count = 0
 	return true, nil
 }

operator-length.go

@@ -30,16 +30,16 @@ func evalLength(ctx ExprContext, opTerm *term) (v any, err error) {
 		s, _ := childValue.(string)
 		v = int64(len(s))
 	} else if IsDict(childValue) {
-		// m, _ := childValue.(map[any]any)
 		m, _ := childValue.(*DictType)
 		v = int64(len(*m))
 	} else if it, ok := childValue.(Iterator); ok {
-		if extIt, ok := childValue.(ExtIterator); ok && extIt.HasOperation(CountName) {
+		v = int64(it.Count())
-			count, _ := extIt.CallOperation(CountName, nil)
+		// if extIt, ok := childValue.(ExtIterator); ok && extIt.HasOperation(CountName) {
-			v, _ = ToGoInt(count, "")
+		// 	count, _ := extIt.CallOperation(CountName, nil)
-		} else {
+		// 	v, _ = ToGoInt(count, "")
-			v = int64(it.Index() + 1)
+		// } else {
-		}
+		// 	v = int64(it.Index() + 1)
+		// }
 	} else {
 		err = opTerm.errIncompatibleType(childValue)
 	}

t_iterator_test.go

@@ -11,7 +11,7 @@ func TestIteratorParser(t *testing.T) {
 	inputs := []inputType{
 		/*   1 */ {`include "test-resources/iterator.expr"; it=$(ds,3); ^it`, int64(0), nil},
 		/*   2 */ {`include "test-resources/iterator.expr"; it=$(ds,3); it++; it++`, int64(1), nil},
-		/*   3 */ {`include "test-resources/iterator.expr"; it=$(ds,3); it++; it++; #it`, int64(2), nil},
+		/*   3 */ {`include "test-resources/iterator.expr"; it=$(ds,3); it++; it++; #it`, int64(3), nil},
 		/*   4 */ {`include "test-resources/iterator.expr"; it=$(ds,3); it++; it++; it.reset; ^it`, int64(0), nil},
 		/*   5 */ {`builtin "math.arith"; include "test-resources/iterator.expr"; it=$(ds,3); add(it)`, int64(6), nil},
 		/*   6 */ {`builtin "math.arith"; include "test-resources/iterator.expr"; it=$(ds,3); mul(it)`, int64(0), nil},
@@ -27,6 +27,6 @@ func TestIteratorParser(t *testing.T) {
 		/*  16 */ {`include "test-resources/filter.expr"; it=$(ds,10); it++`, int64(2), nil},
 	}
 
-	//runTestSuiteSpec(t, section, inputs, 4)
+	//runTestSuiteSpec(t, section, inputs, 3)
 	runTestSuite(t, section, inputs)
 }