Reading Order II

Requirements

• Export sortReadingOrder(items, rowTolerance = 10) as named and default. Each item has finite numeric x and y coordinates and may contain extra fields. Return a new array containing the original item references; do not mutate the input or item objects. TypeScript preserves the item’s extra fields.
• Sort items by y, then x, then original input position. Start a row at the first remaining item’s y. Include subsequent sorted items while their y minus this fixed row anchor is at most rowTolerance. Start a new row when that inclusive tolerance is exceeded.
• The row anchor never changes. Nearby items must not chain together into a row whose total vertical spread exceeds rowTolerance. Order rows by their anchors, and order items inside each row by x, then y, then original input position.
• Negative and fractional coordinates are allowed. Tolerance must be finite and nonnegative; invalid tolerance throws RangeError. Invalid coordinate values throw TypeError. An empty input returns a new empty array. No DOM access, drawing, bounding-box overlap, right-to-left text, or font measurement is required.

Examples

Input: sortReadingOrder([{ id:"b", x:20, y:1 }, { id:"c", x:5, y:20 }, { id:"a", x:0, y:4 }], 5).map(p => p.id);
Output: ["a", "b", "c"]

Input: sortReadingOrder([{x:30,y:0},{x:20,y:8},{x:10,y:16}],10).map(p=>p.y);
Output: [8, 0, 16]; y=16 does not join the row anchored at 0.