J3/06-146

Date:    16-Feb-2006
To:      J3
From:    JOR/Stan Whitlock
Subject: Beginning a source line with a semicolon
Ref:     J3-035

Basic Functionality:
  Remove the restriction against beginning a source line with a
  semicolon.

Rationale:
  This restriction is stated in 3.3.1.3 (for free source form)
  and 3.3.2.4 (for fixed source form) of Fortran 2003.

  This restriction was not in the original F90, but was added
  by F90 corrigendum 3.  It remained in F95.

  It is an unnecessary restriction:  removing it simplies the
  standard.

  The line "; A=B" is a valid continuation line in both free-form
  and fixed-form {assuming the ";" is in column 7 but column 6 is
  non-blank and non-zero}.  The line "; A=B" is not a valid non-
  continued line in free-form and is not a valid initial line in
  fixed-form because the null text to the left of the ";" does not
  form valid statement syntax.

Detailed Specification:
  Remove the restriction against beginning a source line with a
  semicolon as stated in section 3.3.1.3 (for free source form)
  and 3.3.2.3 (for fixed source form) of Fortran 2003.

Edits:
  The edits are against 04-007.

  [29:11-12] Delete the sentence in 3.3.1.3;
             'A ";" shall not appear as the first nonblank character
              on a line.'

  [30:7] In 3.3.2.3 change "a line, except in character position 6."
                    to "an initial line."

         The sentence at [30:6-7] would then read:
         'A ";" shall not appear as the first nonblank character
              on an initial line.'

  These edits do not collide with existing edits in 05-014r1.