On Feb 23, 1:45 pm, Ivan Andrus <darthand...@gmail.com> wrote:
>
> > (RJF) I know of no other programming language that requires this.
>
> C++0x will require something similar for templates, so that
>
> std::vector<SomeType<bool>> x;
>
> will parse instead of requiring
>
> std::vector<SomeType<bool> > x;
>
> That said, I don't think many people consider C++ to be an easy language to
> parse. :-)
>
> -Ivan
that looks similarly nasty.
This semanticdesigns company is using a "GLR" parser, which is fairly
general but
potentially slow if the grammar in use is more ambiguous than not.
I suppose there is another way around this in Mathematica, which is to
not recognize [[ or ]]
as tokens, but only [ and ]. And some investigation shows this is
what they do.
let L={a,b,c,d} a list of 4 elements
L[[2]] evaluates to the 2nd element, namely b.
L[ [ 2 ] ] evaluates to b as well.
There are other 2- or 3- character tokens, such as ==, and ===. The
question
naturally occurs as to whether you can put spaces in the middle of
those too.
A==B tests to see if A is equal to B
A= =B is syntactically incorrect.
Probably a C++ parser would use the same trick and not have a token >>
at all.
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