Simplicity of timespec section, and exec-path-list rationale hga@xxxxxx 29 Jul 2019 12:10 UTC

> From: Lassi Kortela <xxxxxx@lassi.io>
> Date: Monday, July 29, 2019 2:03 AM

> Just read the latest draft of SRFI 170. I like the way the spec is
> going. Especially happy with the simplicity of the timespec section now.

About that....  It's occurred to me that an arithmetic suite of equality,
now to be extended to a comparator, and only difference (is that supposed
to be a delta, or subtraction?) doesn't make much sense.  At minimum, I
think we need addition, and I can see uses for multiplication, like:

(+ timespec (* number-of-seconds-in-a-day number-of-days))

And division to find the inverse.  I suppose constants with the number
of seconds per day and week would not be out of place.  But months are
messy, and years implicate leap years, and if we were to play epoch
games, the 3 centuries over which the Gregorian calendar was adopted.

> Thanks for the continued effort John and Harold!

You're very welcome!  I think I've just about completed the "easy" 80%
of it for Chibi Scheme, leaving the classical 80% of the work for the
hard parts.

> One thing that still puzzles me is exec-path-list. It's a variable that
> mirrors the value of the PATH envar, but "changing the value of PATH may
> or may not not change the value of this variable" so you can't trust it
> when reading it. What are the intended applications of this variable?

I can't answer to the latter, but for a static version, on top of a
Scheme that implements get-environment-variable and the regex SRFI-115,
it's a line of code, plus a bit more for Window's use of ";" for
pathname separation in the PATH environment variable.

- Harold