Re: Empty Alternatives (a.k.a epsilon).

On Tue, Aug 25, 2026, at 12:12, Bethan Tovey-Walsh wrote:
> (I'd also be okay with adding a special symbol to represent the empty string (a.k.a an "epsilon" symbol, for those who are used to such things from other grammatical formalisms), alongside permitting its representation as double quotation marks.)

I'd prefer that empty quotes not be treated as a representation of the empty string; I'd much rather, in a grammar, be able to treat empty quotes as always being some kind of error. Adopting some specific character as "this is the empty string" would be preferable.

Something like U+2205 EMPTY SET seems like a better choice than whatever lingering US keyboard character might be available (as a vi user, % is everything, not nothing), but I seem to recall a policy of only using US keyboard characters.

-- Graydon

--  
Graydon Saunders  | graydonish@fastmail.com
Þæs oferéode, ðisses swá mæg.
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