Re: widget special PREFIX variable and cursor position with complete_in_word

[Bart Schaefer <schaefer@xxxxxxxxxxxxxxxx>]

On Feb 12, 10:02pm, Yuri D'Elia wrote:
}
} I was writing a zstyle widget

I'm not understading what you mean by this.  Are you writing an actual
completion widget, or are you writing a function that will be used as
an argument to compdef, or are you writing a function whose name will
be used as the value of a zstyle?  If the last, which zstyle?

(By "an actual completion widget" I mean it's name will be the third
argument to a "zle -C" command.)

} Without complete_in_word it works fine, PREFIX contains the word up to
} the cursor indeed. However, with complete_in_word, the following:
} 
} $ ls //x<TAB>
} dev/ etc/ lib/ sbin/
} 
} moves the cursor to the first slash (/):
} 
} $ ls //x
}       ^
} dev/ etc/ lib/ sbin/
} 
} In this case, PREFIX contains //x, and not '/' as I would expect.

I'm going to guess that you mean you hit TAB a second time immediately
after the cursor is moved to that spot.

I believe you'll find that the behavior is different depending on
whether you have hit TAB twice in succession or whether you moved the
cursor there yourself before you hit TAB.

Whether what I'm about to describe is what happens may be changed by
some of the setopts and styles, but the default behavior is:

The first time you press TAB, if the result is ambiguous (in your
example, four possible results) a completion listing and the cursor
is moved to the first disambiguating location.  At this point you
have a choice:  Enter a character that will remove the ambiguity,
or hit TAB again to enter menu completion.

If you hit TAB again, the same completion that created the listing
is repeated in order to populate the menu.  If you were to replay it
in slow motion, you'd see the cursor return to the end of the word
before the completion is begun, and then jump back to the point of
disambiguation to insert the first choice from the menu.

Because the original completion is being repeated, PREFIX="//x" as
it was before.  You can detect this by examining $compstate[old_list].
The _oldlist completer takes explicit advantage of this behavior to
avoid calling all the other completers when a list has already been
created.

If instead you were to move the cursor yourself and press TAB, or
press TAB e TAB to explicitly select "etc", *then* the second tab
is beginning a brand new completion with a new PREFIX value.

} Fine with that as long as I can know where the cursor is, but I was
} looking into the $compstate hash and found nothing. I was hoping for
} some offset.

$CURSOR won't lie to you, but you'll find that it reflects what I
described above, i.e., that the cursor returns to the end of the word
before resuming the completion.