trackLineLocation

import std.array;
import std.range;

enum testDocLines = [
    "line 1",
    "line 2",
    "line 3",
    "line 4",
];
auto testDoc = testDocLines.join('\n') ~ '\n';

auto tracker = trackLineLocation(refRange(&testDoc));
// default tracker starts at line 1 column 1
assert(tracker.line == 1);
assert(tracker.column == 1);

// read to end of first line
tracker.popFrontExactly(testDocLines[0].length);
// still on first line but column changed to last column in the line
// which is the newline itself
assert(tracker.line == 1);
assert(tracker.column == testDocLines[0].length + 1);

// pop the newline
tracker.popFront();
// now we are on line 2 column 1
assert(tracker.line == 2);
assert(tracker.column == 1);

// read until the end
tracker.popFrontN(testDoc.length);
assert(tracker.line == 5);
assert(tracker.column == 1);