(Language: D) Filtering an iterable

Writing a basic filtering function template is really simple to do in D. This is akin to a Python's filter() function and will work on anything iterable.

[Source Code] 

  1. import tango.io.Stdout;
  2.  
  3. T[] filter (alias dg, T) (T[] list) {
  4.  
  5.     T[] result;
  6.  
  7.     foreach (T item; list) {
  8.  
  9.         if (dg(item)) {
  10.  
  11.             result ~= item;
  12.  
  13.         }
  14.  
  15.     }
  16.  
  17.     return result;
  18.  
  19. }
  20.  
  21. void main () {
  22.  
  23.     int[] list   = [1,2,3,4,5,6,7,8,9,10];
  24.     int[] result = filter!((int a) {
  25.                        return a % 2 == 0;
  26.                    })(list);
  27.  
  28.     foreach (int item; result) {
  29.  
  30.         Stdout(item).newline();
  31.  
  32.     }
  33.  
  34. }

(Language: C) Swapping case

A very simple example of how to swap character case in an ASCII string. Do not try this on a multi-byte string or you will end up with something possibly resembling goo.

[Source Code] 

  1. #include <stdio.h>
  2. #include <string.h>
  3.  
  4. void swap_case (char* value) {
  5.  
  6.     int i, len;
  7.  
  8.     for (i = 0, len = strlen(value); i < len; i++) {
  9.  
  10.         if (*(&value[i]) >= 97 && *(&value[i]) <= 122) {
  11.  
  12.             *(&value[i]) -= 32;
  13.  
  14.         } else if (*(&value[i]) >= 65 && *(&value[i]) <= 90) {
  15.  
  16.             *(&value[i]) += 32;
  17.  
  18.         }
  19.  
  20.     }
  21.  
  22. }
  23.  
  24. int main (int argc, char** argv) {
  25.  
  26.     char* data = (char*) strdup("A Simple Case Swap Example");
  27.  
  28.     printf("%s\n", data);
  29.  
  30.     swap_case(data);
  31.  
  32.     printf("%s\n", data);
  33.  
  34.     return 0;
  35.  
  36. }