Consider this: w = (x)->y || z
That code is not obvious at all. Which of these would it be?
1: w = function (x) { return y } || z
2: w = function (x) { return y || z }
It seems to me that there must be some sort of delineation
around the function start and end.
But such delineation does not have to lead to required syntax
in the function construct. Such required delineations were not
part of lambda-calculus originally **, they arose out of
implementation limitations that can be overcome.
I know that takes some getting used to (been there myself*),
but there is an established standard, both in publications on
programming language theory, and in some real languages:
function bodies extend as far as possible **
So your examples would be
1: w = (function (x) return y) || z
2: w = (function (x) return y || z)
If the right-hand side itself is delimited, 2 could also be written
2': w = function (x) return y || z
The idea is that we can always "shorten" an unbounded function
by enclosing it with existing grouping constructs, but we cannot
"lengthen" a pre-delineated function in any way, nor can we get
rid of the delineating parens and braces if they are required in
the grammar. Combining non-delineated functions with grouping
constructs gives us a modular and unambiguous solution.
Another issue is that of blocks in function bodies. It would be
nice if blocks were values - then procedures would just be
block-returning functions, and all functions would just return
values, separating the function construct from the details of
block execution. Not sure whether such niceties would work
in javascript, though:-)
Claus
* I used to write my lambda-calculus terms fully parenthesized,
because the functional languages I knew (before Haskell)
required that style. Many programming language theory
folks found that style difficult to read, because they had
grown up with the extends-as-far-as-possible convention.
** Church, Barendregt, .., they all define lambda-terms as
term := x | (\x term) | (term term)
with additional conventions to drop parentheses where
possible, such as
(A B C D) instead of (((A B) C) D)
(\x y z.M) instead of (\x (\y (\z M)))
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