Allen's lambda syntax proposal

Maciej Stachowiak mjs at apple.com
Wed Dec 3 18:18:15 PST 2008


On Dec 3, 2008, at 1:23 PM, Peter Michaux wrote:

> Summary of what I've read:
>
> The syntax \(){} has a named lambda problem if the lambda name starts
> with a 'u'. Depending on whitespace between the backslash and the
> identifier seems like it will cause bugs
>
>  \u03c0(){}
>  \ u03c0(){}
>
> The syntax ^(){} has a semicolon insertion ambiguity. What does the
> following mean?
>
>  x = x
>  ^(){}

I think this has only one possible meaning: an expression statement  
consisting of an assignment of x to itself, followed by an expression  
statement that creates an empty no-argument closure. Do you see  
another possible meaning?

More generally, I can imagine cases that might actually be ambiguous  
but I think they can be fixed in the same way that this is:

x = x
+x


Regards,
Maciej



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