slog: correctly represent the zero Time in a Value

Storing the zero time.Time in a Value and then retrieving it
gave a non-zero time. The reason is that UnixNanos is called
to store a time.Time in a Value, and its result is undefined
for the zero time (or any time before the year 1678 or after 2262,
but I don't think we need to worry about those).

One solution, implemented in this CL, is to use a nil *time.Location
to represent the zero time. the time.Time.Location method never
returns nil, so a Value with a nil *time.Location in its `any` field
cannot be mistaken for any other Value, time.Time or otherwise.

Change-Id: Icba66f2ec16e21ed574c3336e1996ed759ab1c17
Reviewed-on: https://go-review.googlesource.com/c/exp/+/463817
Run-TryBot: Jonathan Amsterdam <jba@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Alan Donovan <adonovan@google.com>
2 files changed
tree: c6efc970a5210d63f65ccc1b769a174f3509ba83
  1. apidiff/
  2. cmd/
  3. constraints/
  4. devtools/
  5. ebnf/
  6. ebnflint/
  7. errors/
  8. event/
  9. inotify/
  10. io/
  11. jsonrpc2/
  12. maps/
  13. mmap/
  14. rand/
  15. shiny/
  16. shootout/
  17. slices/
  18. slog/
  19. sumdb/
  20. typeparams/
  21. utf8string/
  22. .gitattributes
  23. .gitignore
  24. codereview.cfg
  25. CONTRIBUTING.md
  26. go.mod
  27. go.sum
  28. LICENSE
  29. PATENTS
  30. README.md
README.md

exp

PkgGoDev

This subrepository holds experimental and deprecated (in the old directory) packages.

The idea for this subrepository originated as the pkg/exp directory of the main repository, but its presence there made it unavailable to users of the binary downloads of the Go installation. The subrepository has therefore been created to make it possible to go get these packages.

Warning: Packages here are experimental and unreliable. Some may one day be promoted to the main repository or other subrepository, or they may be modified arbitrarily or even disappear altogether.

In short, code in this subrepository is not subject to the Go 1 compatibility promise. (No subrepo is, but the promise is even more likely to be violated by go.exp than the others.)

Caveat emptor.