Improve consistency in printing

[kimikage]

Fixes #188

Before (Julia v1.4.2)

julia> N8f24[1/3 0.2]
1×2 Array{N8f24,2} with eltype Normed{UInt32,24}:
 0.333333  0.2

julia> N8f24[1/3, 0.2]
2-element Array{N8f24,1} with eltype Normed{UInt32,24}:
 0.33333333N8f24
 0.2N8f24

julia> FixedPoint[N0f8(1/3) N0f16(1/3)]
1×2 Array{Error showing value of type Array{FixedPoint,2}:
ERROR: MethodError: no method matching typechar(::Type{FixedPoint})

julia> FixedPoint[N0f8(1/3), N0f16(1/3)]
2-element Array{Error showing value of type Array{FixedPoint,1}:
ERROR: MethodError: no method matching typechar(::Type{FixedPoint})

julia> Normed{UInt128,28}(1)
1.0N100f28

After (Julia v1.4.2)

julia> N8f24[1/3 0.2]
1×2 Array{N8f24,2} with eltype Normed{UInt32,24}:
 0.333333  0.2

julia> N8f24[1/3, 0.2]
2-element Array{N8f24,1} with eltype Normed{UInt32,24}:
 0.33333333
 0.2

julia> FixedPoint[N0f8(1/3) N0f16(1/3)]
1×2 Array{FixedPoint,2}:
 0.333  0.33333

julia> FixedPoint[N0f8(1/3), N0f16(1/3)]
2-element Array{FixedPoint,1}:
 0.333N0f8
 0.33333N0f16

julia> Normed{UInt128,28}(1)
Normed{UInt128,28}(1.0)

[kimikage]

FYI

julia> Float32[1/3 0.2]
1×2 Array{Float32,2}:
 0.333333  0.2

julia> Float32[1/3, 0.2]
2-element Array{Float32,1}:
 0.33333334
 0.2

julia> AbstractFloat[Float16(1/3) Float32(1/3)]
1×2 Array{AbstractFloat,2}:
 0.3333  0.333333

julia> AbstractFloat[Float16(1/3), Float32(1/3)]
2-element Array{AbstractFloat,1}:
  Float16(0.3333)
 0.33333334f0

[kimikage]

FixedPointNumbers.showtype() had performance issues as well as functional issues.

Before

julia> @benchmark FixedPointNumbers.showtype(io, N0f8) # Julia v1.4.2
BenchmarkTools.Trial:
  memory estimate:  192 bytes
  allocs estimate:  4
  --------------
  minimum time:     266.134 ns (0.00% GC)
  median time:      276.998 ns (0.00% GC)
  mean time:        341.150 ns (2.18% GC)
  maximum time:     7.560 μs (92.47% GC)
  --------------
  samples:          10000
  evals/sample:     313

julia> @benchmark FixedPointNumbers.showtype(io, N0f8) # Julia v1.6.0-DEV
BenchmarkTools.Trial:
  memory estimate:  336 bytes
  allocs estimate:  6
  --------------
  minimum time:     441.414 ns (0.00% GC)
  median time:      466.667 ns (0.00% GC)
  mean time:        573.091 ns (11.50% GC)
  maximum time:     242.056 μs (99.73% GC)
  --------------
  samples:          10000
  evals/sample:     198

After

julia> @benchmark FixedPointNumbers.showtype(io, N0f8) # Julia v1.4.2
BenchmarkTools.Trial:
  memory estimate:  0 bytes
  allocs estimate:  0
  --------------
  minimum time:     94.312 ns (0.00% GC)
  median time:      136.266 ns (0.00% GC)
  mean time:        130.076 ns (0.00% GC)
  maximum time:     33.543 μs (0.00% GC)
  --------------
  samples:          10000
  evals/sample:     932

julia> @benchmark FixedPointNumbers.showtype(io, N0f8) # Julia v1.6.0-DEV
BenchmarkTools.Trial:
  memory estimate:  0 bytes
  allocs estimate:  0
  --------------
  minimum time:     139.721 ns (0.00% GC)
  median time:      142.276 ns (0.00% GC)
  mean time:        156.099 ns (0.00% GC)
  maximum time:     63.378 μs (0.00% GC)
  --------------
  samples:          10000
  evals/sample:     861

It's still slow but this PR (and upcoming changes in ColorTypes) can reduce the number of times where the type aliases are printed. Therefore, I will not optimize showtype with a string dictionary or something.

[codecov]

Codecov Report

Merging #189 into master will decrease coverage by 0.05%.
The diff coverage is 92.85%.

@@            Coverage Diff             @@
##           master     #189      +/-   ##
==========================================
- Coverage   89.80%   89.74%   -0.06%     
==========================================
  Files           6        6              
  Lines         461      478      +17     
==========================================
+ Hits          414      429      +15     
- Misses         47       49       +2     

Impacted Files	Coverage Δ
src/utilities.jl	96.00% <ø> (ø)
src/FixedPointNumbers.jl	87.69% <92.59%> (-0.03%)	⬇️
src/fixed.jl	90.26% <100.00%> (+0.08%)	⬆️

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[timholy]

Very nice change! Approved, small tweaks are optional.

[timholy]

Suggested change

	compact = get(io, :compact, false)
	compact = get(io, :compact, false)::Bool

There is no way for inference to know this, so it makes sense to help it.

It's not necessary for the :typeinfo access below because the only way you use it is with === and that's a builtin so there's only one "method."

[kimikage]

BTW, in Base, the default value for :typeinfo seems to be set as Any, not nothing. So, I'll change it to Any.

[timholy]

Interesting to make this conditional on hasalias. Seems sensible.

[kimikage]

I'll make sure that v0.8.4 doesn't have any fatal side effects on the downstream packages, then I'll merge this.

Edit:
Although NanosoldierReports have been sick for the past few days, at least the tests of Images.jl was passed. So, I'll merge this and start v0.9 series.