Stride

[Ali Çehreli]

On 02/12/2012 09:37 AM, RenatoL wrote:
 > Loosing my time on skittles...
 >
 > input "abcd"
 > desired output "arcd"
 > i want to use stride
 >
 > snippet, where x and y are integer in real code:
 >
 >      string s1 = "abcd";
 >      s1 = s1[stride(s1,x)..y] ~ 'r' ~ s1[2..$];
 >
 > if x = 0 and y = 0 ->  run time error. ok
 > if x = 0 and y = 1 ->  "rcd" (??)
 > if x = 1 and y = 0 ->  run time error. ok
 > if x = 1 and y = 1 ->  "rcd"
 > if x = 0 and y = 2 ->  "brcd" (WTF?)
 > if x = 1 and y = 2 ->  "brcd" (...)
 >
 > what the hell of parameters have i to put to achieve "arcd"?

This is yet another problem caused by the dual nature of narrow strings. 
When used with algorithms like stride(), a char[] is *not* a 
RandomAccessRange but when used with the [] operator it is.

According the stride()'s documentation, s1 will lose elements through 
popFront() because of not being a RandomAccessRange.

Related question: Does D define the order of evaluation in an expression 
like

   foo() ~ bar()

Or is it unspecified as in C and C++?

Ali