Digraphs

In 1994 more readable alternatives to five of the trigraphs were supplied. These use only two characters and are known as digraphs. Unlike trigraphs, digraphs are tokens. If a digraph occurs in another token (e.g. string literals or character constants) then it will not be treated as a digraph, but remain as it is.

The following shows the difference before and after processing the digraphs sequence.

#include <stdio.h>

int main()
<%
    printf("Hello %> World!\n"); /* Note that the string contains a digraph */
%>

Which will be treated the same as:

#include <stdio.h>

int main()
{
    printf("Hello %> World!\n"); /* Note the unchanged digraph within the string. */
}

Digraph | Equivalent | :—–: | :—––: | <: | [ | :> | ] | <% | { | %> | } | %: | # |