On Monday, 26 January 2015 at 19:44:18 UTC, Walter Bright wrote:
On 1/26/2015 8:13 AM, Foo wrote:
You could do the same as C++ with override and final: they are
only valid
attributes if they appear _after_ the function/method.
Elsewhere they are still
valid as identifiers for e.g. variables.
Just 'no' on context-sensitive tokens.
For context,
TV vocabulary - 2,000 words
High school vocabulary - 10,000 words
College vocabulary - 30,000 words
English - 1,000,000 words
i.e. words are NOT a scarce resource (quite unlike punctuation).
I'm not sure what you mean by "context-sensitive tokens". It
sounds like you might be saying that this requires the tokenizer
to be context sensitive, but this isn't the case. Instead,
allowing a function to be decorated with any number of "id" or
"keyword" tokens would allow the language to add new attributes
(without a '@' character) by restricting the usage of attributes
in the semantics instead of the syntax.
void myfunc() foo bar safe nogc nothrow {
}
'foo' and 'bar' don't break the syntax but are caught by the
semantic analysis.
Furthermore, I'm sure this type of thing is already done all over
the place in the grammar. The following example comes to mind:
struct St { }
void main()
{
St St;
}
The "St" token is a decl type the first time and a variable name
the second. I'm sure they are implemented as the same token but
the grammar results in a different semantic meaning for both
tokens.
