Here's a simple idea for more readable s-expressions.

readable-s-expressions

Imagine that you have lisp envy, but your brain can't quite handle all
the parentheses. Here's my idea for more readable s-expressions.

When you begin parsing, you start in terminator mode. In terminator
mode, an expression is a series of space separated expressions
terminated by a newline or semicolon:

  print "hello"
  eat "tomatoes"
  clean "dishes"

In traditional s-expressions, this would be:

  ((print "hello") (eat "tomatoes") (clean "dishes"))

Expressions in terminator mode can contain traditional expressions:

  print (str "hello, " name)

And you can flip back into terminator mode with curly braces:

  if (< x 5) {
    print "now we're back in terminator mode"
    print "so we don't have too many parentheses"
  }

Without curly braces, you'd stay in traditional mode in the if body:

  if (< x 5) (
    (print "this time we stayed in traditional mode")
    (print "so newlines are just whitespace")
    (print "and complex expressions must be contained in parens")
  )

Now you can imagine some more complex forms that are still fairly
readable:

  switch x (
    1 {
      print "x is 1"
    }

    2 {
      print "x is 2"
    }

    else {
      if (isSpecial x) {
        print "x isn't 1 or 2, but it is special in some way"
      } else {
        print "I'm bored of x"
      }
    }
  )

That was basically the direction I wad going with the first version of the syntax, but i've since decided the significant newlines are more trouble than they are worth in a c style syntax.

In my new syntax, you can write in either s-expression mode or js style mode and interchange them.