read a file into an array of lines in d
arrays, d, file-io
Solution
Actually, D will double the array's reserved space whenever it runs out of room, so you don't need to do it by hand. There is a lot of information about D's arrays here
Problem
What is the proper way to read a text file into an array of lines? I found the following on Rosetta Stone: ``` string[] readLines(string filename) { auto f = File(filename); scope(exit) f.close(); string[] lines; foreach (str; f.byLine) { lines ~= str.idup; } return lines; } ``` but it looks like it's doing one array resize per line, which is pretty inefficient. I could keep track of the number of lines read in and resize the array via the standard doubling method ``` int i = 0; foreach (str; f.byLine) { if (lines.length <= i + 1) { lines.length = lines.length * 2 + 1; } lines[i] = str.idup; i++; } lines.length = i; ``` but that's enough boilerplate code that I have to wonder if I'm not just overlooking something in the standard library that already does this for me. Edit: giving fwend's comment more visibility: this article describes in detail how the array allocator works, and why appending is handled efficiently by the runtime