repl history/editing

Since we won’t likely to have a fully functioning VIM mode in the new rusty repl, I propose to add the following repl commands to mitigate that:

\e [N] or \edit [N] to open the system $EDITOR for the last (if N isn’t provided), or the last N-th (if N is negative), or the N-th (if N is positive) command.

\s or \history to open a pager with the history of executed commands (latest to oldest), e.g.

[43]
    SELECT User {
        name
    };

[42]
   SELECT 1 / 0;

The user then can press [ESC], enter \e 42 and edit the SELECT 1 / 0 query.

[elprans]

psql uses \s for history shortcut

[tailhook]

First version of the commands is implemented. They currently only support negative numbers, because that allows seamless integration with history. (I.e. with positive numbers it’s unclear whether 1 is a first item in current session or the first history entry, both options have their downsides).

Let me know if that doesn’t work for you.