IFS, set, and positional parameters not doing what I expect

[jason@xxxxxxx]

Howdy

In bash and ksh, I do this a lot:

f="a:b:c"
OFS=$IFS; IFS=: ; set -- $f ; IFS=$OFS

which sets $1=a, $2=b, $3=c.

In zsh, this sets $1=a:b:c.  I've tried mucking around with
the word splitting options to no avail.

What am I missing?

--
Jason