Sweet: an alternative to s-expressions

Asumu Takikawa <asumu@racket-lang.org>

This manual describes the sweet planet package, which is a port of the sweet reader created by David Wheeler to Racket. In the port, you can use the sweet reader as its own separate language.

To use sweet expressions, supply a #lang line like the following:

#lang planet asumu/sweet racket

The third parameter on the #lang line is the base language to be used with sweet expressions. You can supply any language here such as racket, typed/racket, or others.

For example:

#lang planet asumu/sweet typed/racket
define: fact([n : Integer]) : Integer
  if zero?(n)
     {n * fact{n - 1}}

Or alternatively:

#lang planet asumu/sweet lazy
define fibs
  cons 0 cons(1 map(+ fibs cdr(fibs)))
displayln list-ref(fibs 8)

Known issues: quasiquotation combined with grouping behaves differently from the original specification.