J3/13-208

To: J3
From: Van Snyder
Subject: Reduce restrictions on specification functions
Date: 2013 December 19

Title: Reduce restrictions on specification functions

Submitted by: Van Snyder

Status: For consideration

Basic functionality: Allow specification functions to have procedure
arguments.  Allow optional dummy arguments of a procedure to be actual
arguments to specification functions referenced in restricted
expressions.  Prohibit specification functions from being internal only
to a procedure containing a reference to them.

Rationale: Reduces the need for wrappers, and thereby long-term cost.

Markham M6 conformance: Remove simple deficiencies.

Estimated impact: Minor

Detailed specification: Allow a specification function to have procedure
dummy arguments, provided the procedure actual arguments are not
internal to the procedure in which the reference appears.  Allow a
specification function to be an internal procedure, provided it is not
internal to the procedure containing a reference to it.  Allow optional
dummy arguments of a procedure to be actual arguments to specification
functions referenced in restricted expressions.

Draft edits: To estimate scope of project

Replace item (11) in the list in 7.1.11p2 with

  (11) a reference to a specification function where
    (a) each argument corresponding to a dummy data object is a
        restricted expression or a dummy argument that does not have the
        INTENT(OUT) attribute,
    (b) an optional argument of the procedure containing the reference
        that is an actual argument to the specification function
        corresponds to an optional dummy argument of the specification
        function, and
    (c) any procededure corresponding to a dummy procedure is not an
        internal procedure of the scoping unit containing the reference,

Replace 7.1.11p5 with

"A function is a specification function if it is a pure function
\obs{, is not a statement function}, and is not an internal function
in a procedure in which it is referenced."