work on filter.go, needs tests now

filter.go

@@ -5,42 +5,98 @@ import (
 	"exp/html"
 )
 
+// Filter() reduces the set of matched elements to those that match the selector string.
+// It returns a new Selection object for this subset of matching elements.
 func (this *Selection) Filter(selector string) *Selection {
 	return pushStack(this, winnow(this, selector, true))
 }
 
+// Not() removes elements from the Selection that match the selector string.
+// It returns a new Selection object with the matching elements removed.
 func (this *Selection) Not(selector string) *Selection {
 	return pushStack(this, winnow(this, selector, false))
 }
 
+// FilterFunction() reduces the set of matched elements to those that pass the function's test.
+// It returns a new Selection object for this subset of elements.
 func (this *Selection) FilterFunction(f func(int, *Selection) bool) *Selection {
 	return pushStack(this, winnowFunction(this, f, true))
 }
 
+// Not() removes elements from the Selection that pass the function's test.
+// It returns a new Selection object with the matching elements removed.
 func (this *Selection) NotFunction(f func(int, *Selection) bool) *Selection {
 	return pushStack(this, winnowFunction(this, f, false))
 }
 
+// FilterNodes() reduces the set of matched elements to those that match the specified nodes.
+// It returns a new Selection object for this subset of elements.
 func (this *Selection) FilterNodes(nodes ...*html.Node) *Selection {
 	return pushStack(this, winnowNodes(this, nodes, true))
 }
 
+// Not() removes elements from the Selection that match the specified nodes.
+// It returns a new Selection object with the matching elements removed.
 func (this *Selection) NotNodes(nodes ...*html.Node) *Selection {
 	return pushStack(this, winnowNodes(this, nodes, false))
 }
 
+// FilterSelection() reduces the set of matched elements to those that match a node in the specified Selection object.
+// It returns a new Selection object for this subset of elements.
 func (this *Selection) FilterSelection(s *Selection) *Selection {
 	return pushStack(this, winnowNodes(this, s.Nodes, true))
 }
 
+// Not() removes elements from the Selection that match a node in the specified Selection object.
+// It returns a new Selection object with the matching elements removed.
 func (this *Selection) NotSelection(s *Selection) *Selection {
 	return pushStack(this, winnowNodes(this, s.Nodes, false))
 }
 
+// Union() is an alias for FilterSelection().
 func (this *Selection) Union(s *Selection) *Selection {
 	return this.FilterSelection(s)
 }
 
+// Has() reduces the set of matched elements to those that have a descendant that matches the selector.
+// It returns a new Selection object with the matching elements.
+func (this *Selection) Has(selector string) *Selection {
+	sel := this.document.Find(selector)
+	return this.HasSelection(sel)
+}
+
+// HasNodes() reduces the set of matched elements to those that have a descendant that matches one of the nodes.
+// It returns a new Selection object with the matching elements.
+func (this *Selection) HasNodes(nodes ...*html.Node) *Selection {
+	return this.FilterFunction(func(_ int, s *Selection) bool {
+		// Add all nodes that contain one of the specified nodes
+		for _, n := range nodes {
+			if s.Contains(n) {
+				return true
+			}
+		}
+		return false
+	})
+}
+
+// HasSelection() reduces the set of matched elements to those that have a descendant that matches one of
+// the nodes of the specified Selection object.
+// It returns a new Selection object with the matching elements.
+func (this *Selection) HasSelection(sel *Selection) *Selection {
+	return this.HasNodes(sel.Nodes...)
+}
+
+// End() ends the most recent filtering operation in the current chain and returns
+// the set of matched elements to its previous state.
+func (this *Selection) End() *Selection {
+	if this.prevSel != nil {
+		return this.prevSel
+	}
+	return newEmptySelection(this.document)
+}
+
+// Filter based on a selector string, and the indicator to keep (Filter) or
+// to get rid of (Not) the matching elements.
 func winnow(sel *Selection, selector string, keep bool) []*html.Node {
 	cs := cascadia.MustCompile(selector)
 
@@ -50,49 +106,24 @@ func winnow(sel *Selection, selector string, keep bool) []*html.Node {
 	} else {
 		// Use grep
 		return grep(sel, func(i int, s *Selection) bool {
-			return !cs(s.Get(0))
+			return !cs.Match(s.Get(0))
 		})
 	}
 	return nil
 }
 
+// Filter based on an array of nodes, and the indicator to keep (Filter) or
+// to get rid of (Not) the matching elements.
 func winnowNodes(sel *Selection, nodes []*html.Node, keep bool) []*html.Node {
 	return grep(sel, func(i int, s *Selection) bool {
 		return isInSlice(nodes, s.Get(0)) == keep
 	})
 }
 
-// Identical functionality for FilterFunction() and NotFunction(), only keep changes.
+// Filter based on a function test, and the indicator to keep (Filter) or
+// to get rid of (Not) the matching elements.
 func winnowFunction(sel *Selection, f func(int, *Selection) bool, keep bool) []*html.Node {
 	return grep(sel, func(i int, s *Selection) bool {
 		return f(i, s) == keep
 	})
 }
-
-func (this *Selection) Has(selector string) *Selection {
-	sel := this.document.Find(selector)
-
-	return this.HasSelection(sel)
-}
-
-func (this *Selection) HasNode(node *html.Node) *Selection {
-	return this.FilterFunction(func(_ int, s *Selection) bool {
-		// Add all nodes that contain the node specified
-		if s.Contains(node) {
-			return true
-		}
-		return false
-	})
-}
-
-func (this *Selection) HasSelection(sel *Selection) *Selection {
-	return this.FilterFunction(func(_ int, s *Selection) bool {
-		// Add all nodes that contain one of the nodes in the selection
-		for _, n := range sel.Nodes {
-			if s.Contains(n) {
-				return true
-			}
-		}
-		return false
-	})
-}