Re: lpeg question
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- Subject: Re: lpeg question
- From: Roberto Ierusalimschy <roberto@...>
- Date: 2018年3月13日 17:46:14 -0300
> I don't interpret the manual that way. I read that as saying that you
> cannot modify the length operator for a string. But __len is defined
> as a length operation, is it not?
I am not sure what you mean by "__len is defined as a length operation".
It is *called* the length operator, but a name does not give its
semantics. __add is also related to the "addition operation", but that
name does not imply that it is an addition.
Note the following:
1) The __eq metamethod, which always returns a boolean, says so:
"The result of the call is always converted to a boolean."
2) The API for the length operation does not return a number, but a
Lua value. (The same is true for addition, but not for comparisons.)
-- Roberto