RE: emulate readline

[Drew Adams]

> I want to be able to replay all the commands I have typed in, 
> subsetted by their initial string which I have so far typed

Others have given you some info about what comes closest in vanilla Emacs to
what you requested.

In Icicles:

1. `M-h' matches what you've typed so far in the minibuffer against the history
elements.  You can complete to them or cycle among them.

2. `M-pause' filters the current set of matching candidates to ones you've used
previously. Again, you can then complete against or cycle among those.

3. You can use `M-o' at any time (not just during completion) to insert an entry
from the current history into the minibuffer.  Again, you can complete against
or cycle among the candidates.

The difference between #1 and #2 is that #2 narrows the current set of
candidates and #1 matches directly against all history elements.

In all cases, for completion you can match using a prefix, a substring, or a
regexp - au choix.  You can use the up/down arrows to cycle among the current
matches.

There are additional history enhancements.  All are described here:

http://www.emacswiki.org/emacs/Icicles_-_History_Enhancements