Implement --invert to remove tags matching selector.

parse.go

@@ -19,6 +19,7 @@ var (
 	pupPreformatted  bool          = false
 	pupPrintColor    bool          = false
 	pupEscapeHTML    bool          = true
+	pupInvertSelect  bool          = false
 	pupIndentString  string        = " "
 	pupDisplayer     Displayer     = TreeDisplayer{}
 )
@@ -56,6 +57,7 @@ Flags
     -n --number        print number of elements selected
     -l --limit         restrict number of levels printed
     -p --plain         don't escape html
+    -v --invert        invert selection (remove matching elements)
     --pre              preserve preformatted text
     --charset          specify the charset for pup to use
     --version          display version
@@ -89,6 +91,8 @@ func ProcessFlags(cmds []string) (nonFlagCmds []string, err error) {
 			pupPrintColor = true
 		case "-p", "--plain":
 			pupEscapeHTML = false
+		case "-v", "--invert":
+			pupInvertSelect = true
 		case "--pre":
 			pupPreformatted = true
 		case "-f", "--file":

pup.go

@@ -76,5 +76,33 @@ func main() {
 		}
 	}
 	selectedNodes = append(selectedNodes, currNodes...)
-	pupDisplayer.Display(selectedNodes)
+	if pupInvertSelect {
+		RemoveInverseMatches(root, selectedNodes)
+		pupDisplayer.Display([]*html.Node{root})
+	} else {
+		pupDisplayer.Display(selectedNodes)
+	}
+}
+
+func RemoveInverseMatches(root *html.Node, selectedNodes []*html.Node) {
+	var remove []*html.Node
+	for node := root.FirstChild; node != nil; node = node.NextSibling {
+		if HtmlNodeInList(node, selectedNodes) {
+			remove = append(remove, node)
+		} else {
+			RemoveInverseMatches(node, selectedNodes)
+		}
+	}
+	for _, rm := range remove {
+		root.RemoveChild(rm)
+	}
+}
+
+func HtmlNodeInList(a *html.Node, list []*html.Node) bool {
+	for _, b := range list {
+		if b == a {
+			return true
+		}
+	}
+	return false
 }

tests/cmds.txt

@@ -47,3 +47,4 @@ link , a:parent-of(sup)
 link , a:parent-of(sup) sup
 li	--number
 li	-n
+li a	--invert

tests/expected_output.txt

@@ -47,3 +47,4 @@ b6a3d6cccd305fcc3e8bf2743c443743bdaaa02b link , a:parent-of(sup)
 0d1f66765d1632c70f8608947890524e78459362 link , a:parent-of(sup) sup
 d200756078ef79d77fb17848c5f15b85bcea7e00 li	--number
 d200756078ef79d77fb17848c5f15b85bcea7e00 li	-n
+1fa074385374bcd613394678b5e08ed1ad4d5d9d li a	--invert