To: J3                                                     J3/23-216
From:      Brad Richardson
Subject:   F2023 interp: CHANGE TEAM to INITIAL_TEAM
Date: 2023-September-26

NUMBER: F18/		! /interp assigns number after submission
TITLE: 			CHANGE TEAM to INITIAL_TEAM
KEYWORDS: 		CHANGE TEAM, INITIAL_TEAM, TEAM_TYPE
DEFECT TYPE: 		! /interp assigns
STATUS: J3 consideration in progress

QUESTION:

Is it valid to execute a CHANGE TEAM statement with a team-value
specifying the initial team?

Consider the following example program.

  USE ISO_FORTRAN_ENV
  TYPE(TEAM_TYPE) :: t
  t = GET_TEAM(INITIAL_TEAM)
  CHANGE TEAM (t)
     ! ...
  END TEAM
  END

In Section 11.1.5.2 it states:

> The team-values on the active images that execute the CHANGE TEAM
> statement shall be those of team variables defined by corresponding
> executions of the same FORM TEAM statement (11.7.9). When the
> CHANGE TEAM statement is executed, the current team shall be the
> team that was current when those team variables were defined.

The second sentence leaves it somewhat ambiguous as to whether the
above program is valid. What variable corresponds to the value that
is returned by GET_TEAM(INITIAL_TEAM) and when/how was it defined?

ANSWER 1:

No. It was not intended to be able to CHANGE TEAM to the initial
TEAM. Specifically, the value returned by GET_TEAM(INITIAL_TEAM) was
not defined by execution of a FORM TEAM statement, and thus is not a
valid team-value for a CHANGE TEAM statement. It would be beneficial
to make this clear though.

EDITS to 23-007r1 for ANSWER 1:

[192:31] after "corresponding executions of the same FORM TEAM
        statement (11.7.9)", insert "and it shall not have the value
        returned by the intrinsic function GET_TEAM with argument
        INITIAL_TEAM"

ANSWER 2:

The value returned by GET_TEAM(INITIAL_TEAM) is considered to have
been defined by the initial team, and is a valid team-value for
a CHANGE TEAM statement when the current team is the initial team.

EDITS to 23-007r1 for ANSWER 2:

[192:32] After "when those team variables were defined" insert
        ", or the current team shall be the initial team and the
        team-value shall have the value returned by the intrinsic
        function GET_TEAM with argument INITIAL_TEAM"

ANSWER 3:

The value returned by GET_TEAM(INITIAL_TEAM) is considered to have
been defined by the current team, and is a valid team-value for
any CHANGE TEAM statement.

EDITS to 23-007r1 for ANSWER 3:

[192:32] After "when those team variables were defined" insert
        ", or the team-value shall have the value returned by the
        intrinsic function GET_TEAM with argument INITIAL_TEAM"

SUBMITTED BY: Brad Richardson

HISTORY: yy-nnn    mxxx  F18/nnnn submitted

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