Text editing [Was: Re: #line decoder]

[bearophile]

Sergey Gromov, there's a bug in your code, you don't perform the dup, so the contents of all the string slices are lost. This is a bug-prone feature of the current D, I have done several times similar bugs in the past.

The timings:

Updated timings:
Timings, data2.txt, warm timings, best of 3:
  loader1:    23.05 s
  loader2:     3.00 s
  loader3:    44.79 s
  loader4:    39.28 s
  loader5:    21.31 s
  loader6:     7.20 s
  loader7:     7.51 s
  loader8:     8.45 s
  loader9:     5.46 s
  loader10:    3.73 s
  loader10b:  3.88 s
  loader11:   82.54 s
  loader12:   38.87 s
  loader13:   28.28 s
  loader14:   15.37 s
  loader13:    6.74 s (no GC)
  loader14:    6.94 s (no GC)


Your code I have used:

// loader13
import std.stream: BufferedFile;
import std.string: split;
//import std.gc: enable, disable;

class Rope(T) {
    private {
        T[][] chunks;
        T[] current;
        size_t pool;
    }
    this() {
        current = new T[16];
        pool = 0;
    }
    typeof(this) opCatAssign(T el) {
        if (pool >= current.length) {
            chunks ~= current;
            current = new T[current.length * 2];
            pool = 0;
        }
        current[pool++] = el;
        return this;
    }
    T[] get() {
        T[] result;
        foreach (c; chunks)
            result ~= c;
        return result ~ current[0 .. pool];
    }
}

void main() {
    //disable();
    auto fin = new BufferedFile("data2.txt");
    alias Rope!(string) SRope;
    SRope[] result;
    foreach (el; split(cast(string) fin.readLine())) {
        result ~= new SRope;
        result[$-1] ~= el;
    }

    foreach (char[] line; fin)
        foreach (id, el; split(cast(string) line))
            result[id] ~= el.dup;

    auto month = result[0].get();
    auto day = result[1].get();
    auto num = result[2].get();
    //enable();
}



// loader14
import std.stream: BufferedFile;
import std.string: split;
//import std.gc: enable, disable;

class Array(T) {
    private {
        T[] data;
        size_t pos;
    }
    this() {
        data = new T[16];
    }
    typeof(this) opCatAssign(T el) {
        if (pos == data.length)
            data.length = data.length * 2;
        data[pos++] = el;
        return this;
    }
    T[] get() {
        return data[0 .. pos];
    }
}

void main() {
    //disable();
    auto fin = new BufferedFile("data2.txt");
    alias Array!(string) SArray;
    SArray[] result;
    foreach (el; split(cast(string) fin.readLine())) {
        result ~= new SArray;
        result[$-1] ~= el;
    }

    foreach (char[] line; fin)
        foreach (id, el; line.split())
            result[id] ~= el.dup;

    auto month = result[0].get();
    auto day = result[1].get();
    auto num = result[2].get();
    //enable();
}

Bye,
bearophile