Using regular expressions when reading a file

[Ali Çehreli]

On 5/5/22 12:05, Alexander Zhirov wrote:
> On Thursday, 5 May 2022 at 18:58:41 UTC, H. S. Teoh wrote:
>> You don't have to. Just add a `$` to the end of your regex, and it 
>> should match the newline. If you put it outside the capture 
>> parentheses, it will not be included in the value.
> 
> In fact, it turned out to be much easier. It was just necessary to use 
> the `m` flag instead of the `s` flag:
> 
> ```d
> auto p_property = regex(r"^(\w+) *= *(.+)", "m");
> ```
> 

Couldn't help myself from improving. :) The following regex works in my 
Linux console. No issues with '\n'. (?) It also allows for leading and 
trailing spaces:

import std.regex;
import std.stdio;
import std.algorithm;
import std.array;
import std.typecons;
import std.functional;

void main() {
   auto p_property = regex(r"^ *(\w+) *= *(\w+) *$");
   const properties = File("settings.conf")
                      .byLineCopy
                      .map!(line => matchFirst(line, p_property))
                      .filter!(not!empty) // OR: .filter!(m => !m.empty)
                      .map!(m => tuple(m[1], m[2]))
                      .assocArray;

   writeln(properties);
}

Ali