(j3.2006) scope of implicitly declared entities in BLOCK constructs

[Bill Long]

Robert Corbett wrote:
> As the draft Fortran 2008 standard is currently written,
> a data entity that is implicity declared in a BLOCK
> construct has the scope of the outermost scoping unit
> that contains it.  Thus,
>
>        PROGRAM MAIN
>          BLOCK
>            I = 10
>          END BLOCK
>          PRINT *, I
>        END
>
> conforms to the draft standard, but
>
>        PROGRAM MAIN
>          BLOCK
>            INTEGER I
>            I = 10
>          END BLOCK
>          PRINT *, I
>        END
>
> does not.  Is that the intent of the committee?
>
>   
I hope so.  One obvious use of a block construct is to put BLOCK and END 
BLOCK around an existing section of code for the purpose of adding a 
new, local declaration and some additional statements using the new 
variables.  You don't want previously present variables in the section 
of code to suddenly have their scoping change.  If that were to happen, 
you would end up with unexpected, and hard to track-down bugs.

Cheers,
Bill

-- 
Bill Long                                   longb at cray.com
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