It does accept a union, but a module import is a finite map (from identifiers to their definitions), not just a set. The union is only well defined if all duplicated keys map to the same values. In this case, one import maps image? to the definition in htdp, and the other maps image? to the definition in 2htdp. The union is not well defined, so combine-in must fail.
On 10/8/13, Stephen Chang <[email protected]> wrote: > What is the intended use case of combine-in? The docs says it does a > union but that doesnt seem to be true. > > (require (combine-in lang/htdp-beginner 2htdp/image)) > > module: identifier already imported from a different source in: > image? > (rename 2htdp/image image? image?) > (rename lang/htdp-beginner image? image?) > ____________________ > Racket Users list: > http://lists.racket-lang.org/users > > -- Carl Eastlund ____________________ Racket Users list: http://lists.racket-lang.org/users
