ceil static method
Returns the smallest (closest to negative infinity) value that is greater than or equal to the argument a
and is equal to a mathematical integer.
Implementation
static num ceil(num a) {
if (a is int) return a;
if (a is double) {
if (a.isNaN || a.isInfinite) return a;
}
var n = a.toInt();
if (n == a) return n;
return n + 1;
}