std/options: $some(3) is now "some(3)", etc.

[timotheecour]

refs #17036 (comment)

• $some(3) is now "some(3)", not "Some(3)", $none(int) is now "none(int)" instead of "None[int]"
• use -dnimLagacyOptionsDollar for previous behavior.

rationale:

• Some and None don't exist as symbols
• Some(3) would imply you'd have a type Some, but then Some(3) syntax would be illegal
• it also makes more sense in the syntax of fusion/matching, see below

note

I've disabled optionsutils which had a failing test due to this change:

tests/test2.nim(57, 17): Check failed: echoed == "Some(10)"
      echoed was some(10)
tests/test2.nim(61, 17): Check failed: echoed == "None[int]"
      echoed was none(int)

Future work

• I can send a PR to optionsutils (=> PR followup https://github.com/nim-lang/Nim/pull/17147 PMunch/nim-optionsutils#4)
• re-enable this package after this PR is merged
  => re-enable pkg optionsutils #17231
• fusion/matching should also use some and none instead of Some and None:

{.experimental: "caseStmtMacros".}
import fusion/matching
case some(42)
of Some(@a): assert a == 42
of None(): assert false
assertMatch(some(some(none(int))), Some(Some(None())))

=> this:

{.experimental: "caseStmtMacros".}
import fusion/matching
case some(42)
of some(@a): assert a == 42
of none(): assert false # or maybe `none` instead of `none()`
assertMatch(some(some(none(int))), some(some(none())))

(EDIT: followup discussing this point here: timotheecour#612)

[konsumlamm]

Regarding fusion/matching, I think it would be more consistent to keep using Some and None, since that fits in with using uppercase kinds for variant objects.

EDIT(timotheecour): let's followup discussing fusion/matching renaming Some, None to some, none in here: timotheecour#612