To: J3                                                     J3/18-251r1
From:       Jon Steidel
Subject:    Are internal procedures allowed in generic interface blocks
Date: 2018-October-16

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NUMBER: F18/0002
TITLE:  Internal procedures in generic interface blocks
KEYWORDS: Internal procedure, generics interface block
DEFECT TYPE: Erratum
STATUS: New

QUESTION:

An internal procedure is allowed in a GENERIC statement, but
apparently it cannot appear in a generic interface block.

Section 15.4.3.4.1 (12.4.3.4.1 in F2008) Generic identifiers p1 states
  "A generic interface block specifies a generic interface for each
   of the procedures in the interface block.  The PROCEDURE statement
   lists procedure pointers, external procedures, dummy procedures,
   or module procedures that have this generic interface."

Is the apparent prohibition of internal procedures in the PROCEDURE
statement intended?

ANSWER:

No, this was not intended.  An internal procedure should be allowed
in a generic interface body. An edit are provided to correct this
mistake.

DISCUSSION:

In F2003, Section 12.3.2.1 Interface Block has rule R1206

   <procedure-stmt>    is [MODULE] PROCEDURE <procedure-name-list>

with constraint C1270

    "A <procedure-name> shall have an exlicit interface and shall
     refer to an accessible procedure pointer, external procedure,
     dummy-procedure, or module procedure."

Edits in paper 05-202r1 allowed internal procedures to be passed as
actual arguments and to be targets of procedure pointers. This meant
an internal procedure could be the target of a procedure pointer which
was specified in a generic interface body.

Paper 08-178 asked the question "What is the point of excluding
internal procedure in C1207?" and replaced C1207 with

   "A <procedure-name> shall be a nonintrinsic procedure that has an
    explicit interface."

The normative text cited in the question was not modified.
This was an oversight.

EDITS to 18-007r1:

[294:11-12] 15.4.3.4.1 Generic identifiers, p1, second sentence,
            Change "procedure pointers, external procedures, dummy
                    procedures, or module procedures"
            to "nonintrinsic procedures with explicit interfaces".

This makes the sentence read:
  "The PROCEDURE statement lists nonintrinsic procedures with explicit
   interfaces that have this generic interface."

SUBMITTED BY: Jon Steidel

HISTORY: 18-251   m217 Submitted
         18-251r1 m217 Revised

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