Either-or Packages

If a function does not throw, return the function return value; otherwise, return `y`.

If a function does not throw, return the function return value; otherwise, return the return value of a second function.

If a function does not return an error, invoke a callback with the function result; otherwise, invoke a callback with a value `y`.

If a function does not return an error, invoke a callback with the function result; otherwise, invoke a second function.

If a predicate function returns a truthy value, return `x`; otherwise, return `y`.

If a predicate function returns a truthy value, invoke `x`; otherwise, invoke `y`.

If a condition is truthy, return `x`; otherwise, return `y`.

If a condition is truthy, invoke `x`; otherwise, invoke `y`.