[J3] please try running this program

Steve Lionel steve at stevelionel.com
Tue Oct 25 01:01:22 UTC 2022

On 10/24/2022 8:45 PM, Malcolm Cohen via J3 wrote:

> We did not change the scoping rules for this in Fortran 2018. And we 
> know this because we did not list such a change in the compatibility 
> clauses.

I believe this, but I think I understand why Bob thought otherwise. I'll 
admit that sometimes the fine points elude me, but...

A derived type definition is a scoping unit (3.123). The scope of a 
local variable is an inclusive scope (19.4).  Inclusive scope is 
"nonblock scoping unit plus every block scoping unit whose host is that 
scoping unit or that is nested within such a block scoping unit" (3.87). 
References to N2209.

I read this as saying that the scope of a variable whose implicit 
declaration is inside a derived type definition is that type definition. 
If there are words that say otherwise, I haven't found them yet.

Why is a derived type definition a scoping unit? Is it to restrict the 
scope of its named components? If so, it seems to me that has some 
unwanted side-effects.

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