Actually, it's special syntax for infix operators, regardless of how many arguments they have. For instance, when writing contracts, prefix notation looks like this:
(-> integer? integer? boolean?) ...while infix notation looks like this: (integer? integer? . -> . boolean?) Equivalently, you could write this, although with contracts it wouldn't make as much sense: (integer? . -> . integer? boolean?) Whatever single s-expression is between the two periods gets moved to the front of the list by the reader. I don't know what => means in formlets. Carl Eastlund On Thu, Nov 17, 2011 at 4:38 PM, Grant Rettke <gret...@acm.org> wrote: > The dual dot is a special syntax for things with two arguments. > > Eg: > > (1 . + . 3) > > (4 . / . 2) > > On Thu, Nov 17, 2011 at 3:26 PM, Jordan Schatz <jor...@noionlabs.com> wrote: >> What does => mean? I see it used in formlets: >> From http://docs.racket-lang.org/web-server/formlets.html?q=formlets >> >> like: >> >> (define date-formlet >> (formlet >> (div "Month:" ,{input-int . => . month} >> "Day:" ,{input-int . => . day}) >> (list month day))) >> >> Which I think should be and appears to be equal to: >> >> (define date-formlet >> (formlet >> (div "Month:" ,{=> input-int month} >> "Day:" ,{=> input-int day}) >> (list month day))) >> >> But what does the => do? Is it a form of apply? >> >> Thanks, >> Jordan >> _________________________________________________ >> For list-related administrative tasks: >> http://lists.racket-lang.org/listinfo/users >> > > > > -- > http://www.wisdomandwonder.com/ > ACM, AMA, COG, IEEE _________________________________________________ For list-related administrative tasks: http://lists.racket-lang.org/listinfo/users
