Re: [boost] Ternary logic programming

Subject: Re: [boost] Ternary logic programming
From: Bjorn Reese (breese_at_[hidden])
Date: 2015-07-03 05:45:17

On 07/02/2015 02:49 AM, Niall Douglas wrote:

> Out of interest, what do you think of my free function ternary logic
> programming:

So far, the discussion has focussed on how the ternary operators should
behave in if-statements. In that case, I tend to agree with Lee's enum
and switch suggestion, which also extends well into multi-variate logic.

If we want to use the ternary logic in if-statements, then we should
address composite conditions. For instance, what should the following
evaluate to?

   if (Empty && Value) {}

   if (Empty && Error) {}

   if (Empty && Empty) {}

The question really boils done to what influence Empty has. Do we want
it to influence the results, or should it act like a "don't care" value?

PS: Niall, I know that you are currently using Kleene logic, but I think
that it is worthwhile to consider the use-cases before selecting the
truth tables.