J3/13-208r1

To: J3
From: Van Snyder
Subject: Reduce restrictions on specification functions
Date: 2013 February 11

Title: Reduce restrictions on specification functions

Submitted by: Van Snyder

Status: For consideration

Basic functionality: Allow specification functions to have procedure
dummy arguments, provided the corresponding actual arguments are not
internal.  Allow optional dummy arguments of a procedure to be actual
arguments to specification functions referenced in restricted
expressions, providing the corresponding dummy argument of the
specification function is optional.

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 corresponding actual arguments are not
internal.  Allow optional dummy arguments of a procedure to be actual
arguments to specification functions referenced in restricted
expressions, providing the corresponding dummy argument of the
specification function is optional.

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,

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."