Re: Can LPeg do basic arithmetic?

[Coda Highland <chighland@...>]

On Tue, Jul 5, 2016 at 2:11 PM, Soni L. <fakedme@gmail.com> wrote:
>
>
> On 05/07/16 05:18 PM, Sean Conner wrote:
>>
>> It was thus said that the Great Soni L. once stated:
>>>
>>> As you may or may not know by now, regex can do basic arithmetic, with
>>> unary integers.[1] Can LPeg do better, say with binary integers, or
>>> binary floats, or even full-blown decimal?
>>
>>    Yup.  You can do the regex approach with a substitution capture
>> (lpeg.Cs()) or even a full blown calculator (there's an example on the
>> LPeg
>> web page).
>
> Too bad it's not pure LPeg, instead deferring to a Lua function for it.

Well, considering that regular expressions are capable of doing it,
and LPeg is capable of implementing regular expressions, by
isomorphism LPeg is capable of performing arithmetic.

What would be far more interesting is if you could implement an
expression parser that would actually return the value if you pass in
the formula as a human-readable string. (I've got some ideas on how
you could accomplish that...)

/s/ Adam