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digitalmars.D.learn - Clearing associative array.

reply ciechowoj <keepitsimplesirius gmail.com> writes:
Could someone explain to me, why following code does not compile?

int main()
{
	string[string] x = [ "foo" : "bar" ];
	x.clear();
	x = [];

	return 0;
}

Errors:
main.d(7): Error: no property 'clear' for type 'string[string]'
main.d(8): Error: cannot implicitly convert expression ([]) of 
type void[] to string[string]
Failed: ["dmd", "-v", "-o-", "main.d", "-I."]

If above doesn't work how am I supposed to clear the array? `x = 
string[string].init;` is somewhat ugly.

dmd --version
DMD64 D Compiler v2.070.0
Copyright (c) 1999-2015 by Digital Mars written by Walter Bright
Mar 12 2016
parent reply Adam D. Ruppe <destructionator gmail.com> writes:
On Saturday, 12 March 2016 at 12:34:16 UTC, ciechowoj wrote:

 If above doesn't work how am I supposed to clear the array? `x 
 = string[string].init;` is somewhat ugly.


Read the Tip of the Week section here:

http://arsdnet.net/this-week-in-d/dec-13.html

Short answer: use `= null` to clear the AA. [] doesn't work just 
because the compiler is a bit stupid about the type you intend it 
to be, but null works fine.

BTW you might want to glance through more of the issues for the 
tip section too and see if there's more that interest you.
Mar 12 2016
parent reply ciechowoj <keepitsimplesirius gmail.com> writes:
On Saturday, 12 March 2016 at 12:42:04 UTC, Adam D. Ruppe wrote:

 On Saturday, 12 March 2016 at 12:34:16 UTC, ciechowoj wrote:

 If above doesn't work how am I supposed to clear the array? `x 
 = string[string].init;` is somewhat ugly.


 Read the Tip of the Week section here:

 http://arsdnet.net/this-week-in-d/dec-13.html

 Short answer: use `= null` to clear the AA. [] doesn't work 
 just because the compiler is a bit stupid about the type you 
 intend it to be, but null works fine.

 BTW you might want to glance through more of the issues for the 
 tip section too and see if there's more that interest you.


Nice article :), thanks. But still, what about clear()? In the 
documentation https://dlang.org/spec/hash-map.html#properties 
there is written that associative arrays have clear property.
Mar 12 2016
next sibling parent reply Adam D. Ruppe <destructionator gmail.com> writes:
On Saturday, 12 March 2016 at 12:59:02 UTC, ciechowoj wrote:

 Nice article :), thanks. But still, what about clear()? In the 
 documentation https://dlang.org/spec/hash-map.html#properties 
 there is written that associative arrays have clear property.


I don't think that actually works... might be out of date 
documentation, I'm not sure.
Mar 12 2016
parent Steven Schveighoffer <schveiguy yahoo.com> writes:
On 3/12/16 8:09 AM, Adam D. Ruppe wrote:

 On Saturday, 12 March 2016 at 12:59:02 UTC, ciechowoj wrote:

 Nice article :), thanks. But still, what about clear()? In the
 documentation https://dlang.org/spec/hash-map.html#properties there is
 written that associative arrays have clear property.


 I don't think that actually works... might be out of date documentation,
 I'm not sure.


Opposite. The next version of dmd will have a clear property.

Apparently, we don't have a good system to merge doc changes in concert 
with future master releases. Whatever gets pulled apparently gets built 
as the current docs.

See PR: https://github.com/D-Programming-Language/dlang.org/pull/1217

-Steve
Mar 15 2016
prev sibling parent reply cym13 <cpicard openmailbox.org> writes:
On Saturday, 12 March 2016 at 12:59:02 UTC, ciechowoj wrote:

 On Saturday, 12 March 2016 at 12:42:04 UTC, Adam D. Ruppe wrote:

 On Saturday, 12 March 2016 at 12:34:16 UTC, ciechowoj wrote:

 If above doesn't work how am I supposed to clear the array? 
 `x = string[string].init;` is somewhat ugly.


 Read the Tip of the Week section here:

 http://arsdnet.net/this-week-in-d/dec-13.html

 Short answer: use `= null` to clear the AA. [] doesn't work 
 just because the compiler is a bit stupid about the type you 
 intend it to be, but null works fine.

 BTW you might want to glance through more of the issues for 
 the tip section too and see if there's more that interest you.


 Nice article :), thanks. But still, what about clear()? In the 
 documentation https://dlang.org/spec/hash-map.html#properties 
 there is written that associative arrays have clear property.


The problem was brought up a few days ago (can't remember where) 
and it happens to be a documentation mistake: there is a clear() 
method planned but for a future release (the next one?).
Mar 13 2016
parent ciechowoj <keepitsimplesirius gmail.com> writes:
On Sunday, 13 March 2016 at 13:42:02 UTC, cym13 wrote:

 The problem was brought up a few days ago (can't remember 
 where) and it happens to be a documentation mistake: there is a 
 clear() method planned but for a future release (the next one?).


That would be great : )
Mar 13 2016