Golang go/ast.NotNilFilter() function example

package go/ast

NotNilFilter returns true for field values that are not nil; it returns false otherwise.

Golang go/ast.NotNilFilter() function usage example

 func Print(fset *token.FileSet, x interface{}) error {
  return Fprint(os.Stdout, fset, x, NotNilFilter)
 }

Reference :

http://golang.org/pkg/go/ast/#NotNilFilter