[Readable-discuss] wisp as draft SRFI-119

[Arne B. <arn...@we...>]

Hi,

Wisp is now in draft state as SRFI-119: http://srfi.schemers.org/srfi-119/

The version up there is mostly what we discussed here. The main part
which changed are the clarifications.

- To represent tail notation like (define (foo . args)), either avoid
  a linebreak before the dot as in define : foo . args or use a double
  dot to start the line: . . args. The first dot mark the line as
  continuation, the second enters the scheme code.

- A dot as symbol at the end of a line is reserved for potential
  future use. It should be a syntax error if the next non-empty line
  starts with non-zero indentation. A lone dot at the end of a line
  calls for hard to catch errors.

- A dot as only symbol in a line has no useful meaning: the line is by
  definition empty. As such, a dot as only symbol on a line is also
  reserved for future use and should be treated as a syntax error to
  avoid locking out future possibilities.


The part I like best in the draft is the example which shows all
features of wisp (including compatibility with curly infix)
in just 7 lines:


define : factorial n
__  if : zero? n
____   . 1
____   * n : factorial {n - 1}

display : factorial 5 
newline


Best wishes,
Arne