cells(filter?)

Generator function that lazily yields matching cells in the quadrille, each as an object of the form { row, col, value }.

Traversal is row-major (top to bottom, left to right). Returns an IterableIterator—not an array—so values are produced on demand.

Examples

No filter: yield all cells

q.cells();

Function filter: value-based predicate

q.cells(({ value }) => value != null);

Use also Quadrille.isFilled(value), Quadrille.isEmpty(value), or a custom predicate.

Function filter: row and column predicates

// even rows and columns less than 4
q.cells(({ row, col }) => row % 2 === 0 && col < 4);

Function filter: combined value, row, and col predicates

q.cells(({ value, row, col }) =>
  typeof value === 'string' &&
  row % 2 === 0 &&
  col < 4
);

Array / Set filter: whitelist of values

q.cells(['a', 'b', 'c']);
q.cells(new Set([1, 2, 3]));

Yields cells whose value is included.

Advanced: transform or analyze matching cells

// Extract values from filled cells in the top-left 4×4 block
const values = Array.from(q.cells(({ value, row, col }) =>
  Quadrille.isFilled(value) && row < 4 && col < 4
)).map(({ value }) => value);

Use this when:

• you need an array of matching cells,
• you’re chaining with array methods like map or reduce,
• or you’re doing offline processing or analysis.

Syntax

cells() cells(filter)

Parameters