J3/99-146r1

Date:    27th May 1999
To:      J3
From:    Malcolm Cohen
Subject: Unresolved issue 9


1. Introduction

In issue 9 Richard Maine makes 2 suggestions:
(1) allowing initialisation of objects containing allocatable components
    (at least to NULL()) and
(2) allowing PARAMETERs of these types.

I concur.

Since this makes

  TYPE T2
    REAL,ALLOCATABLE :: X
  END TYPE
  TYPE(T2) :: V => T(NULL())

legal, perhaps

  TYPE T
    REAL,ALLOCATABLE :: X => NULL()
  END TYPE

should be legal also (for consistency)?  On the other hand, this adds no
functionality at all and is an entirely redundant initialization, so I
propose
NOT adding it.  If it is required, edits are required to [43:30-34] at
least.

2. A related issue

This was just unresolved issue 10, so it is already in the document.

3. Edits

Comments on each edit appear in {}.

{Allow intrinsic structure constructors for things with alloc comps}
[62:37-39] Delete.

{Alter constraint to allow parameters of d.t.s with alloc comps}
[70:32-33] Delete "a derived-type ... allocatable,"

{Alter constraint to allow d.t.s with alloc comps to be initialised}
[71:18-19] Delete "a derived-type ... allocatable,"

{Delete J3 note}
[71:21-41] Delete.

{Alter constraint to allow <initialization> for allocatables}
[71:18] Delete "an allocatable variable,".

{Alter another constraint to allow <initialization> for allocatables}
[71:42-43] After "shall have the" insert "ALLOCATABLE or".
           After "shall not have the" insert insert "ALLOCATABLE or".

{Fix text to allow, and provide semantics for, initialization of
allocatables}
[73:29-30] Replace first sentence with
           "If <object-name> is a pointer and <initialization> is =>NULL(),
            the initial association status of the pointer is disassociated.
            If <object-name> is allocatable and <initialization> is
=>NULL(),
            the initial allocation status of the allocatable object is
            confirmed to be not allocated.".
{Note that the previous text had a requirement duplicating part of the
 constraint 71:42-43; I have removed this duplicate requirement.}

{Allow d.t.s with alloc comps to be init'ed in DATA}
[93:43-44] Delete.

{Require structure constructors for such things to have NULL() for the alloc
comps}
[94:31-32] Change "each component shall be an initialization expression" to
           "it shall be an initialization expression".

{Allow NULL() for allocatable components in structure constructors to be
 considered to be "constant" expressions.}
[141:37] After "each" insert "nonallocatable".
         Replace "no component ... attribute" with
            "each <component-spec> corresponding to an allocatable component
is
             a reference to the transformational intrinsic function NULL".

{The same for initialization expressions.}
[143:1-2] After "each" insert "nonallocatable".
          Replace "no component ... attribute" with
          "each <component-spec> corresponding to an allocatable component
is
           a reference to the transformational intrinsic function NULL".