Crashing CSV

csv.d

module csv;

import std.algorithm;
import std.array;
import std.range;
import std.conv;
import std.traits;
import std.stdio;

void main() {
    string str = "Hello,World\nsimple,test";

    auto records = csvText(str);
    
    auto record = records.front;
    assert(record.front == "Hello");
    record.popFront();
    assert(record.front == "World");

    foreach(r; csvText(str)) {
        foreach(cell; r) {
            writeln(cell);
        }
    }
}

RecordList csvText(string data) {
    return RecordList(data);
}

/**
 * Range which provides access to CSV Records and Tokens.
 */
struct RecordList
{
private:
    string _input;
    bool _empty;
    Record recordRange;
public:
    this(string input)
    {
        _input = input;
        prime();
    }

    this(this)
    {
        recordRange._input = &_input;
    }

    @property auto front()
    {
        return recordRange;
    }

    @property bool empty()
    {
        return _input.empty;
    }

    void popFront()
    {
        prime();
    }

    void prime()
    {
        recordRange = typeof(recordRange)(&_input);
    }
}

struct Record {
private:
    string* _input;
    string curContentsoken;
    bool _empty;
public:
    this(string* input)
    {
        _input = input;
        prime();
    }

    @property string front()
    {
        assert(!empty);
        return curContentsoken;
    }

    @property bool empty()
    {
        return (*_input).empty;
    }

    void popFront()
    {
        prime();
    }

    void prime() {
        auto count = countUntil(*_input, ',');
        string ans;
        if(count != -1) {
            ans = (*_input)[0..count];
            *_input = (*_input)[count+1..$];
            curContentsoken = ans;
            return;
        }

        ans = *_input;
        *_input = null;
        curContentsoken = ans;
    }
}