On 2012-04-11 11:42:20 -0700, lothar atheling wrote: > usually an (if ...) form without an else part does not cause an error. > > but sometimes it does, as the following shows:
In what situation does a single-branch `if` succeed for you? >From the Racket guide: "An if form must have both a then-expr and an else-expr; the latter is not optional." Do you mean that in most languages a single-branch `if` is valid? If so, Racket is different in this regard because conditionals are expressions---and evaluated for its value---rather than statements with side-effects. Cheers, Asumu ____________________ Racket Users list: http://lists.racket-lang.org/users
