[texhax] tikz: arrows "in the middle"

[Victor Ivrii]

There are two and a half questions I cannot find in pgf manual:

1) I want to connect two points by a line with an arrow but I want an
arrow to be"in the middle":

\draw [->] (0,0)--(0,2);
\draw (0,2)--(0,4);

seems to be cumbersome; it becomes really bad if the line is curved by
..controls..

2) I want path like


\draw [->] (0,0)--(0,2)--(1,1)--(0,0);

but with arrow tips

\draw [->] (0,0)--(0,2);
\draw [->] (0,2)--(1,1);
\draw [->] (1,1);--(0,0);

also seems to be too cumbersome;

2') I want path like in 2) but with an arrows like in 1)

Are there any shortcuts?

Thanks!

Victor