internal/number: improve conformance

- Use patterns also for Inf
- Allow zero precision (and thus an empty result)
  CLDR patterns don’t allow specifying this, but
  fmt pattrens do. We allow it by means of extension.
- Support AlwaysSign flag in case negative patterns
  aren’t specified. This allows passing fmt flag
  behavior for most default Decimal and Scientific

Change-Id: I22104a92e12da11465584eaab9ffd8320a1f469d
Run-TryBot: Marcel van Lohuizen <>
TryBot-Result: Gobot Gobot <>
Reviewed-by: Nigel Tao <>
2 files changed