User Story

As an end-user, I want to use formula autocomplete and argument hints to minimize typing and syntax errors.

Acceptance Criteria

1. After typing an = followed by a few letters, display a drop-down list of built-in functions that match the typed letters below the formula bar or in line editor. (This is the most basic case, but should work in any position within the formula.)
2. Use the mouse or keyboard (up and down arrow keys followed by tab or enter keys) to select a function from the drop-down list and insert into the formula. Or use the escape key to close the drop-down list.
3. After inserting a function, display its list of required and [optional] arguments. (This is the most basic case, but should also work when navigating through the formula using the mouse or left and right arrow keys).

Details