Supplemental support for numerical and mathematical functions

[kimikage]

In response to #179, I checked the support status and performance of some other functions. The (incomplete) list is shown below.

To be supported

• [ ] ^(::FixedPoint, ::Integer) for more accuracy
  • e.g. N0f8(0.8)^3 != N0f8(64/125)
• [x] bitstring (PR #195)
• [x] big (Issue #184, PR #186)
• [x] clamp (Issue #179, PR #194)
• [x] copysign(x::Fixed, y) and flipsign(x::Fixed, y) for speed performance (PR #187)
• [ ] fma and muladd
• [x] rationalize (Issue #184, PR #186)
• [x] 3-arg rem and div (cld) (PR #226, PR #230)
• [ ] rem2pi and mod2pi
• [x] signbit for speed performance (for Normed) (PR #187)

To be dropped

• [x] abs(::Normed) specialization is not helpful. (PR #187)
  • The fallback implementation works fine.
• [x] copysign(x::Normed, y) and flipsign(x::Normed, y) should be throw error. (PR #187)

TBD

• maxintfloat (maxintfixed and minintfixed?)

• parse and tryparse for fixed point numbers with suffix

• bit shift operators (Issue #250)

  • I think they are usuful but somewhat dangerous.

• numerator and denominator

• widemul

[kimikage]

Ah, I forgot widemul.