reading file byLine

[Namal via Digitalmars-d-learn]

On Saturday, 5 September 2015 at 18:57:52 UTC, deed wrote:
> On Saturday, 5 September 2015 at 17:31:39 UTC, Namal wrote:
>> Yeah, I have have been trying this example from wiki books
>>
>> https://en.wikibooks.org/wiki/Learning_D_With_Project_Euler
>>
>> It is not even compiling.
>
> What exactly is not compiling?

the last codesample on the bottom. I think because of the old D? 
Index for the last array.length-1 is now $-1. But also I get

Error: undefined identifier 'file'

for the read line. But even when I fixed those errors the strings 
I got were with those quotation marks and backslashes. However, 
with your help I could solve it now.

I moved to the next problem and wrote the program for it

import std.stdio, std.algorithm, std.array;

bool abundant(int n){
	
	int[] a;
	
	foreach(i;1..n)
		if(!(n%i))
			a~=i;
	auto sum = reduce!((a,b)=>a+b)(0,a);
	
	return sum>n;
}



void main(){
	
	long sum;
	int[] arr;
	int[28123] mark;
	
	foreach(i;1..28124)
		if(abundant(i))
			arr~=i;
	
	foreach(i;arr)
	foreach(j;arr){
		
		if(i+j>28123)
			break;
		mark[i+j-1] = 1;
	}
	for(auto i = 0;i<mark.length;++i)
		if(!mark[i])
			sum+=i+1;
	writeln(sum);
}

How can I generate the array arr the functional way with reduce 
and the function abundant as filter. Tried it on my own but 
failed. Also, if I use reduce on an array, like I did for the 
sum, what does the zero mean in the range?