Procedure to split words

CREATE OR ALTER PROCEDURE PRO_SEPARA_PALAVRAS (
    APALAVRA VARCHAR(1000),
    AORDEM VARCHAR(4))
RETURNS (
    RESULT VARCHAR(1000))
AS
  DECLARE VARIABLE SUB VARCHAR(1000);
  DECLARE VARIABLE I INTEGER;
BEGIN
  IF (UPPER(:AORDEM) = 'ASC') THEN
  BEGIN
    I = 1;
    RESULT = '';
    SUB = :APALAVRA;

    WHILE (I <= CHARACTER_LENGTH(:APALAVRA)) DO
    BEGIN
      IF (SUBSTRING(:SUB FROM 1 FOR 1) = ' ') THEN
      BEGIN
        SUSPEND;
        RESULT = '';
      END
      ELSE
        RESULT = RESULT || SUBSTRING(:SUB FROM 1 FOR 1);

      SUB = SUBSTRING(:SUB FROM 2 FOR CHARACTER_LENGTH(:SUB));

      I = I + 1;
    END

    SUSPEND;
  END
  ELSE
  IF (UPPER(:AORDEM) = 'DESC') THEN
  BEGIN
    RESULT = '';
    SUB = :APALAVRA;

    WHILE (CHARACTER_LENGTH(:SUB) > 0) DO
    BEGIN
      IF (SUBSTRING(:SUB FROM CHARACTER_LENGTH(:SUB) FOR 1) = ' ') THEN
      BEGIN
        RESULT = REVERSE(RESULT);
        SUSPEND;
        RESULT = '';
      END
      ELSE
        RESULT = RESULT || SUBSTRING(:SUB FROM CHARACTER_LENGTH(:SUB) FOR 1);

      SUB = SUBSTRING(:SUB FROM 1 FOR CHARACTER_LENGTH(:SUB)-1);
    END

    RESULT = REVERSE(RESULT);
    SUSPEND;
  END
END