add marks.RemoveAll

RemoveAll filters marks from a set of cty.PathValueMarks, removing all
instances of the remove parameter in all paths. If a path has no
remaining marks, it is removed entirely.

Author: jbardin

internal/lang/marks/paths.go

@@ -41,6 +41,28 @@ func PathsWithMark(pvms []cty.PathValueMarks, wantMark any) (withWanted []cty.Pa
 	return withWanted, withOthers
 }
 
+// RemoveAll take a series of PathValueMarks and removes the unwanted mark from
+// all paths. Paths with no remaining marks will be removed entirely. The
+// PathValuesMarks passed in are not cloned, and RemoveAll will modify the
+// original values, so the prior set of marks should not be retained for use.
+func RemoveAll(pvms []cty.PathValueMarks, remove any) []cty.PathValueMarks {
+	if len(pvms) == 0 {
+		// No-allocations path for the common case where there are no marks at all.
+		return nil
+	}
+
+	var res []cty.PathValueMarks
+
+	for _, pvm := range pvms {
+		delete(pvm.Marks, remove)
+		if len(pvm.Marks) > 0 {
+			res = append(res, pvm)
+		}
+	}
+
+	return res
+}
+
 // MarkPaths transforms the given value by marking each of the given paths
 // with the given mark value.
 func MarkPaths(val cty.Value, mark any, paths []cty.Path) cty.Value {

internal/lang/marks/paths_test.go

@@ -58,6 +58,40 @@ func TestPathsWithMark(t *testing.T) {
 	}
 }
 
+func TestRemoveAll(t *testing.T) {
+	input := []cty.PathValueMarks{
+		{
+			Path:  cty.GetAttrPath("sensitive"),
+			Marks: cty.NewValueMarks("sensitive"),
+		},
+		{
+			Path:  cty.GetAttrPath("other"),
+			Marks: cty.NewValueMarks("other"),
+		},
+		{
+			Path:  cty.GetAttrPath("both"),
+			Marks: cty.NewValueMarks("sensitive", "other"),
+		},
+	}
+
+	want := []cty.PathValueMarks{
+		{
+			Path:  cty.GetAttrPath("sensitive"),
+			Marks: cty.NewValueMarks("sensitive"),
+		},
+		{
+			Path:  cty.GetAttrPath("both"),
+			Marks: cty.NewValueMarks("sensitive"),
+		},
+	}
+
+	got := RemoveAll(input, "other")
+
+	if diff := cmp.Diff(want, got, ctydebug.CmpOptions); diff != "" {
+		t.Errorf("wrong matched paths\n%s", diff)
+	}
+}
+
 func TestMarkPaths(t *testing.T) {
 	value := cty.ObjectVal(map[string]cty.Value{
 		"s": cty.StringVal(".s"),