On 2020-12-16 12:25, Blaise--- via fpc-devel wrote:
On 16.12.2020 12:24, Michael Van Canneyt via fpc-devel wrote:
To be correct: Result is not the name of the result value, it is an
alias.
I did not dispute that. The important point here is: "an alias" to
/what/?
You can still use the function name for the result, so "Result" is in
fact an alias for the function name
Result is not "an alias for the function name" because you cannot use
Result to refer to the function:
-------8<-------
function Foo: Integer;
var X: function : Integer;
begin
Result(); // ERROR
X := Result; // ERROR
end;
-------8<-------
It is a _local_ alias for the name of the _currently_executed_ function
which is valid just within the scope of that function. When invoking the
function recursively, you refer to _another_ instance of that function
and thus the alias is not valid at that point in time, because it
becomes an alias again only when the recurrently called function starts.
Thus it's equivalent to the following example (it compiles due to {$MODE
TP}; in other modes the local can be replaced with another name with the
same effects):
{$MODE TP}
function Foo: Integer;
var
X: Integer absolute Foo;
begin
X := 123;
end;
begin
WriteLn (Foo);
end.
the function name, which is the actual name for the result value.
I can get behind this notion; however, within the function, that name
is overloaded. Thus, we should not say, like Sven did, that Result
aliases the function (name); we should say, like I did, that it
aliases the return value (name).
But, conceptually, I would rather look at the function name resolving
to the return value as a backward-compatible alias, and say that
Result is the true (default) name for the return value. Such notion
fits modern usage.
Modern or not - use of the function name for assignment of the return
value is part of Pascal definition, isn't it? What's the point of
changing the "true name"?
Tomas
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