• Manfred_Nowak (7/7) Dec 10 2010 What is the rationale for having both: normal and square brackets?
• Simen kjaeraas (9/15) Dec 10 2010 Mostly that C has both. Changing this would make the language feel rathe...
• Steven Schveighoffer (4/8) Dec 10 2010 er.. make that O(lg(n)) :) Essentially sub-linear.
• Simen kjaeraas (4/13) Dec 10 2010 Ah, yes. Sorry.
• Manfred_Nowak (6/7) Dec 10 2010 ... and I meant "_constant_ runtime in case of arrays".

"Manfred_Nowak" <svv1999 hotmail.com> writes:

What is the rationale for having both: normal and square brackets?

I ask because in plain old C I interpreted the lexical difference of 
funtion calls and accesses to elements of arrays as a permanent hint for 
linear runtime in case of arrays. But because of `opIndex' this assumption 
has been invalidated a long time ago.
 
-manfred 

"Simen kjaeraas" <simen.kjaras gmail.com> writes:

Manfred_Nowak <svv1999 hotmail.com> wrote:

 What is the rationale for having both: normal and square brackets?

Mostly that C has both. Changing this would make the language feel rather
more different from C/C++ than it already does.

It is also syntactic sugar for element lookup. Rather than having to
write some function name (that may or may not be the same for all
collections), you can use [].


 I ask because in plain old C I interpreted the lexical difference of
 funtion calls and accesses to elements of arrays as a permanent hint for
 linear runtime in case of arrays.

 But because of `opIndex' this assumption has been invalidated a long
 time ago.

No it hasn't. opIndex should still  be O(1), it just can't be enforced.

-- 
Simen

"Steven Schveighoffer" <schveiguy yahoo.com> writes:

On Fri, 10 Dec 2010 09:42:51 -0500, Simen kjaeraas  
<simen.kjaras gmail.com> wrote:

 Manfred_Nowak <svv1999 hotmail.com> wrote:

 But because of `opIndex' this assumption has been invalidated a long
 time ago.

 No it hasn't. opIndex should still  be O(1), it just can't be enforced.

er.. make that O(lg(n)) :)  Essentially sub-linear.

-Steve

"Simen kjaeraas" <simen.kjaras gmail.com> writes:

Steven Schveighoffer <schveiguy yahoo.com> wrote:

 On Fri, 10 Dec 2010 09:42:51 -0500, Simen kjaeraas  
 <simen.kjaras gmail.com> wrote:

 Manfred_Nowak <svv1999 hotmail.com> wrote:

 But because of `opIndex' this assumption has been invalidated a long
 time ago.

 No it hasn't. opIndex should still  be O(1), it just can't be enforced.

 er.. make that O(lg(n)) :)  Essentially sub-linear.

Ah, yes. Sorry.


-- 
Simen

"Manfred_Nowak" <svv1999 hotmail.com> writes:

Steven Schveighoffer wrote:

 Essentially sub-linear.

... and I meant "_constant_ runtime in case of arrays".

BTW: did you notice, that the modell assumption of an access time 
independent from the total length of a used slice of memory seems to become 
wrong?

-manfred