User Story

As an end-user, I want keikai can auto-complete a formula missing the last parenthesis like =SUM(A1:A5 , so that it will be more convenient and user-friendly.

Acceptance Criteria

When a user enters a formula without the last ending parentheses and presses TAB, arrow key, or Enter key, Keikai can auto-complete the formula without producing an error.

Details

• Excel supports this feature
• just consider the simplest case, missing ')' in the end.
• Doesn't handle the case when a formula needs 2 or more ending parentheses e.g. =SUM(SUM(B2). For this case, the formula needs 2 parentheses and is missing 1. Excel also doesn't auto-complete this case.

proposed spec

• If a formula doesn't end with a parenthesis, append 1 before sending to a server.
• If a formula ends with a parenthesis, do nothing. Even the whole formula could be wrong.