SQL & PL/SQL

I Have this procedure that I want to convert to a pipeline function.

Its from this discussion:

sql - recursive permutation algorithm in plsql - Stack Overflow

The original solution from stackflow works but once I try to convert it to pipeline function it fails. I am on oracle12c

The compile error is

Compilation failed,line 16 (21:41:43)
PLS-00221: 'PRINT_ANAGRAMS2' is not a procedure or is undefinedCompilation failed,line 16 (21:41:43)
PL/SQL: Statement ignored

My code is

CREATE OR REPLACE EDITIONABLE TYPE "T_TF_ROW" AS OBJECT (
  --id NUMBER,
  description VARCHAR2(500)
)
/
CREATE OR REPLACE EDITIONABLE TYPE "T_TF_TAB" IS TABLE OF t_tf_row
/
create or replace function print_anagrams2
  (pre in varchar2, str in varchar2) RETURN t_tf_tab PIPELINED AS
    prefix varchar2(30);
    stringg varchar2(30);
    strlen number;
  begin
    strlen := length(str);
    if NVL(strlen, 0) = 0 then
     --dbms_output.put_line(pre);
--PIPE ROW(t_tf_row(i, 'Description for ' || i));
PIPE ROW(t_tf_row(pre));
    else
      for i in 1..strlen loop
        prefix := pre || SUBSTR(str,i,1);
        stringg := SUBSTR(str,1,i - 1) || SUBSTR(str,i+1,strlen);
        print_anagrams2(prefix,stringg);
      end loop;
    end if;
  end;

Message was edited by: kayaman808