gistfile1.js

a = m.map(e => m.vector.apply(null, e), a_poly.vertices)
b = m.map(e => m.vector.apply(null, e), b_poly.vertices)

m.equals(m.set(a),
         m.set(b))

// you could cache the hash, so whenever and area (or polygon) is created/updated
// you would store the hash on it; inside the poly class (or Area)

v = m.map(e => m.vector.apply(null, e), this.vertices)
this._hash = m.hash(m.set(v))