• Alexei Averchenko (5/5) Jan 18 2007 I discovered an issue with nested functions: they must be declared
• Frits van Bommel (24/29) Jan 18 2007 http://www.digitalmars.com/d/function.html#nested (at the end of the
• Alexei Averchenko (2/5) Jan 18 2007 I understand. But the thing is I can't call nested function even from th...
• Frits van Bommel (3/10) Jan 18 2007 I think that's the *entire* limitation. Not being able to call it from a...

Alexei Averchenko <lex.aver mail.ru> writes:

I discovered an issue with nested functions: they must be declared
before used. Is this a bug or a lenguage limitation. Whatever it is,
please resolve this issue, because it screwes the very idea of nested
functions, making it hard to read and maintain the code. Thanks in
advance.

Frits van Bommel <fvbommel REMwOVExCAPSs.nl> writes:

Alexei Averchenko wrote:
 I discovered an issue with nested functions: they must be declared
 before used. Is this a bug or a lenguage limitation. Whatever it is,
 please resolve this issue, because it screwes the very idea of nested
 functions, making it hard to read and maintain the code. Thanks in
 advance.

http://www.digitalmars.com/d/function.html#nested (at the end of the 
section):

*****
Unlike module level declarations, declarations within function scope are 
processed in order. This means that two nested functions cannot mutually 
call each other:

void test()
{
     void foo() { bar(); }	// error, bar not defined
     void bar() { foo(); }	// ok
}

The solution is to use a delegate:

void test()
{
     void delegate() fp;
     void foo() { fp(); }
     void bar() { foo(); }
     fp = &bar;
}

Future directions: This restriction may be removed.
*****

So it's a limitation. Someday it may be removed, but until then there's 
a workaround available.

Alexei Averchenko <lex.aver mail.ru> writes:

Frits van Bommel Wrote:

 Unlike module level declarations, declarations within function scope are 
 processed in order. This means that two nested functions cannot mutually 
 call each other:

I understand. But the thing is I can't call nested function even from the
function in which it was declared before the declaration. Is this the
limitation too?

Frits van Bommel <fvbommel REMwOVExCAPSs.nl> writes:

Alexei Averchenko wrote:
 Frits van Bommel Wrote:
 
 Unlike module level declarations, declarations within function scope are 
 processed in order. This means that two nested functions cannot mutually 
 call each other:

 
 I understand. But the thing is I can't call nested function even from the
function in which it was declared before the declaration. Is this the
limitation too?

I think that's the *entire* limitation. Not being able to call it from a 
nested function defined before it is just one manifestation of it.