Why I'm getting this "Range Violation" error?

[Ali Çehreli]

On 7/9/21 12:21 AM, rempas wrote:

 >    while (prompt[i] != '{' && i < len) {

In addition to what others said, you can take advantage of ranges to 
separate concerns of filtering and iteration. Here are two ways:

import core.stdc.stdio;
import std.algorithm;

// Same as your original
void print(T)(string prompt, T args...) {
   prompt
     .filter!(c => c != '{')
     .each!(c => printf("%c", c));

   // If you are not familiar with the shorthand lambda syntax,
   // I read c => foo(c) as "given c, produce foo(c)."
   //
   // Well... 'each' is different because it does not
   // produce anything. It its case: "given c, do this."
}

// This one dispatches filtering to another function but
// still uses a 'foreach' loop
void print2(T)(string prompt, T args...) {
   foreach (c; prompt.sansCurly) {
     printf("%c", c);
   }
}

// I used R instead of 'string' in case it will be more useful
auto sansCurly(R)(R range) {
   return range.filter!(c => c != '{');
}

void main() {
   print("Hello, {world!\n", 10);
   print2("Hello, {world!\n", 10);
}

Ali