formattedRead whitespace quirks (compared to scanf)

[Ali Çehreli]

On 12/25/2013 12:43 PM, Gordon wrote:

 > -- in C --
 > char a[100] = {0};
 > chat *input = "hello world 42";
 > sscanf(input, "%s", &a);
 > -- in D --
 > string a;
 > string input = "hello world 42";
 > formattedRead(input,"%s", &a);
 > -----------
 >
 > In "C", the variable "a" would contain only "hello";
 > In "D", the variable "a" would contain "hello world 42";
 >
 > BUT,
 > If the format string would be "%s %s %d" (and we had three variables),
 > then "formattedRead()" would behave exactly like "sscanf()".

That is by design. Since a string can contain space characters, the 
normal behavior is to read everything as a part of the the string. scanf 
is defined differently.

However, just like scanf, a space character in the format string matches 
zero or more whitespace characters in the input and ignores them. So, 
"%s %s %d" means to read and ignore the spaces between the three data 
that you are reading.

By the way, you almost never need anything but %s in D; unlike scanf, 
formattedRead() actually knows the exact types of its parameters, so %s 
works for integers as well.

Ali