On Apr 26, 2:42=A0pm, Mike <Sulfate...@[EMAIL PROTECTED]
> wrote:
> On Apr 25, 11:28=A0am, Dave Seaman <dsea...@[EMAIL PROTECTED]
> wrote:
>
>
>
>
>
> > On Thu, 24 Apr 2008 19:32:55 -0700 (PDT), Mike wrote:
> > > On Apr 24, 9:20=A0pm, Dave Seaman <dsea...@[EMAIL PROTECTED]
> wrote:
> > >> On Thu, 24 Apr 2008 00:38:34 -0700 (PDT), Mike wrote:
> > >> > On Apr 23, 10:31=A0pm, nos...@[EMAIL PROTECTED]
(Richard Maine)
wrote:
> > >> >> Dave Seaman <dsea...@[EMAIL PROTECTED]
> wrote:
> > >> >> > The problem is
> > >> >> > using the same name in two conflicting ways.
>
> > [ ... ]
>
> > >> Perhaps this example will help.
> > >> =A0 module scoping
> > >> =A0 =A0 implicit none
> > >> =A0 =A0 integer :: sz =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 !
s=
z is a module variable
> > >> =A0 contains
> > >> =A0 =A0 subroutine a
> > >> =A0 =A0 =A0 sz =3D 3 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0
=A0 =
=A0 =A0! this changes the module variable sz
> > >> =A0 =A0 end subroutine a
> > >> =A0 =A0 subroutine b
> > >> =A0 =A0 =A0 integer :: sz =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 !
s=
z is a local variable
> > >> =A0 =A0 =A0 sz =3D 5 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0
=A0 =
=A0 =A0! this changes the local variable sz
> > >> =A0 =A0 end subroutine b
> > >> =A0 =A0 subroutine c(sz)
> > >> =A0 =A0 =A0 integer, intent(inout) :: sz =A0 =A0 =A0! sz is a dummy
a=
rgument
> > >> =A0 =A0 =A0 sz =3D sz + 1 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0
=A0=
! this changes the dummy argument sz
> > >> =A0 =A0 end subroutine c
> > >> =A0 end module scoping
> > >> The scope of a local variable or a dummy argument is just the
procedu=
re
> > >> containing that declaration. =A0The scope of a module variable is
the=
> > >> entire module, *excluding* any procedure that has a local variable
or=
> > >> dummy argument of the same name. =A0The scope of the module
variable =
SZ
> > >> here is the entire module, *except* for subroutines B and C, which
ha=
ve
> > >> overridden the name SZ to mean something else.
> > > thank you for your explanation.
> > > If the program or procedure use the module scoping, how to say the
> > > scope of SZ now? =A0Does it mean that SZ extends to program or
> > > procedure?
>
> > If any scoping unit contains a USE statement, the effect is the same
as
> > if all the PUBLIC variables in the USEd module were declared at that
> > point. =A0The scope is the program, module, or procedure that contains
t=
he
> > USE statement, exactly as it would be for any ordinary variable
> > declaration.
>
> > >> The rule is that you can't have a variable declared twice in the
same=
> > >> scope. =A0
>
> > Note carefully the words "in the same scope". =A0That's the whole
point =
of
> > the example. =A0You can have two different variables with the same
name,=
> > provided they are in different scopes.
>
> > > If the program or procedure USE the module scoping and it has
variable=
> > > SZ, does it mean SZ is in the same scope of
> > > program main
> > > USE scoping
> > > SZ=3D10.
> > > !may I say SZ is in the same scope of program main & module scoping?
>
> > I only see one variable SZ in either scope. =A0The rule says you can't
h=
ave
> > two variables named SZ in the same scope, but it's perfectly ok to
have
> > one, which is shared between both. =A0That's exactly what the USE
statem=
ent
> > is designed to do.
>
> > > end program main
> > > The module above does not violate this rule, because the
> > >> different instances of SZ are declared in different scopes. =A0The
ru=
le
> > >> means that you can't declare SZ twice as a module variable in the
sam=
e
> > >> module, or declare it once as a module variable and also im****t a
> > >> variable of the same name from some other module in a USE
statement.
> > >> However, you could do something like this:
> > >> =A0 module othermod
> > >> =A0 =A0 use scoping, othersz =3D> sz
> > >> =A0 =A0 implicit none
> > >> =A0 =A0 real :: sz
> > >> =A0 =A0 [ ... ]
> > >> This is not a conflict, because the SZ from module SCOPING has been
> > >> renamed to OTHERSZ in the current scope, allowing SZ in this module
t=
o
> > >> refer to the REAL variable declared here.
> > > Let me add some more statements as following:
> > > module othermod
> > > =A0 =A0 use scoping, othersz =3D> sz
> > > =A0 =A0 implicit none
> > > =A0 =A0 real :: sz
> > > contains
> > > =A0 =A0subroutine app(sz)
> > > =A0 =A0 =A0 integer, intent(inout) :: sz =A0 =A0 =A0! sz is a dummy
ar=
gument
> > > =A0 =A0 =A0 sz =3D sz + 1 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0
=A0 =
! this changes the dummy
> > > argument sz
> > > =A0 =A0end subroutine app
> > > end module othermod
>
> > Ok, so far.
>
> > > program main
> > > =A0 =A0use scoping
> > > =A0 =A0use othermod
>
> > You can't do this, because both modules have a public variable named
SZ,=
> > and this would cause both to be im****ted into the scope of program
MAIN.=
> > You need to modify at least one of those USE statements above to
prevent=
> > this, perhaps by using a rename clause or an ONLY clause, so that the
> > name SZ is im****ted only once.
>
> > > =A0 =A0 implicit none
> > > =A0 =A0sz=3D10.
> > > =A0 =A0print *,sz
> > > =A0 =A0call a
> > > =A0 =A0print *,sz
> > > =A0 =A0call b
> > > =A0 =A0print *,sz
> > > =A0 =A0call c(sz)
> > > =A0 =A0print *,sz
> > > =A0 =A0call app(sz)
> > > =A0 =A0print *,sz
> > > end
> > > It seems in 4th line "real :: sz" needs to be replaced by =A0"real
::
> > > othersz".
>
> > You mean in module OTHERMOD? No, that's not allowed. =A0The name
OTHERSZ=
> > already refers to a variable in module SCOPING (because of the rename
> > clause "othersz =3D> sz"), and therefore you cannot redeclare it in
modu=
le
> > OTHERMOD. =A0However, if you change the name SZ in OTHERMOD to
something=
> > else that doesn't conflict with any other names in that scope, that
will=
> > solve the conflict that arises from USEing both modules in program
MAIN.=
>
> > > In the subroutine app(sz), the dummy argument is sz. =A0It has no
> > > compiled error.
> > > Why? =A0didn't you mean I need to rename SZ to othersz as a dummy
> > > argument?
>
> > No, because the two variables are in different scopes. =A0The one
im****t=
ed
> > from module SCOPING has a scope here that is equal to module OTHERMOD,
> > *excluding* subroutine APP, which has a dummy argument by the same
name
> > that shadows (renders invisible) the one im****ted from SCOPING.
>
> > --
> > Dave Seaman
> > Third Circuit ignores precedent in Mumia Abu-Jamal ruling.
> > <http://www.indybay.org/newsitems/2008/03/29/18489281.php>-
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> Since I have a lot conflict variables with module files in main
> program, to prevent rename so many, I use derived type.
> Declare a derived type in the module like:
>
> module XXX
> type ComboVar
> =A0 =A0real :: sz
> =A0 =A0...... =A0!all of the arguments need to pass to some procedure
> end type ComboVar
> type(ComboVar) :: cVar
>
> Then in main program
> use XXX, cVar1=3D>cVar
Oh, sorry. No need to change name of cVar here.
So simply: use XXX
> cVar1=3DComboVar(sz,.....); =A0<=3D=3D to prevent modifying so many sz
in =
main
> program.
cVar=3DComboVar(sz,.....);
>
> Thank you very much.
>
> Mike- Hide quoted text -
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