Fix repr on Period Types, and DateTime, Date (#30817)

- Given `x = Dates.Day(1)`
 - The REPL will print: `1 day`
 - show will print: `Dates.Day(1)`
 - repr will print: `Dates.Day(1)`
 - print will print: `1 day`
 - string will print: `1 day`
 - dataframes will print: `1 day`

Author: fchorney

stdlib/Dates/docs/src/index.md

@@ -244,7 +244,7 @@ Date
       value: Int64 735264
 
 julia> t.instant
-Dates.UTInstant{Day}(735264 days)
+Dates.UTInstant{Day}(Day(735264))
 
 julia> Dates.value(t)
 735264
@@ -400,7 +400,7 @@ As a bonus, all period arithmetic objects work directly with ranges:
 
 ```jldoctest
 julia> dr = Date(2014,1,29):Day(1):Date(2014,2,3)
-Date(2014, 1, 29):1 day:Date(2014, 2, 3)
+Date(2014, 1, 29):Day(1):Date(2014, 2, 3)
 
 julia> collect(dr)
 6-element Array{Date,1}:
@@ -412,7 +412,7 @@ julia> collect(dr)
  Date(2014, 2, 3)
 
 julia> dr = Date(2014,1,29):Dates.Month(1):Date(2014,07,29)
-Date(2014, 1, 29):1 month:Date(2014, 7, 29)
+Date(2014, 1, 29):Month(1):Date(2014, 7, 29)
 
 julia> collect(dr)
 7-element Array{Date,1}:

stdlib/Dates/src/io.jl

@@ -529,6 +529,14 @@ end
 
 # show
 
+function Base.show(io::IO, p::P) where P <: Period
+    if get(io, :compact, false)
+        print(io, p)
+    else
+        print(io, P, '(', p.value, ')')
+    end
+end
+
 function Base.show(io::IO, dt::DateTime)
     if get(io, :compact, false)
         print(io, dt)
@@ -539,9 +547,9 @@ function Base.show(io::IO, dt::DateTime)
         s = second(dt)
         ms = millisecond(dt)
         if ms == 0
-            print(io, "DateTime($y, $m, $d, $h, $mi, $s)")
+            print(io, DateTime, "($y, $m, $d, $h, $mi, $s)")
         else
-            print(io, "DateTime($y, $m, $d, $h, $mi, $s, $ms)")
+            print(io, DateTime, "($y, $m, $d, $h, $mi, $s, $ms)")
         end
     end
 end
@@ -559,7 +567,7 @@ function Base.show(io::IO, dt::Date)
         print(io, dt)
     else
         y,m,d = yearmonthday(dt)
-        print(io, "Date($y, $m, $d)")
+        print(io, Date, "($y, $m, $d)")
     end
 end
 

stdlib/Dates/src/periods.jl

@@ -45,8 +45,8 @@ for period in (:Year, :Month, :Week, :Day, :Hour, :Minute, :Second, :Millisecond
 end
 
 #Print/show/traits
-Base.string(x::Period) = string(value(x), _units(x))
-Base.show(io::IO,x::Period) = print(io, string(x))
+Base.print(io::IO, p::Period) = print(io, value(p), _units(p))
+Base.show(io::IO, ::MIME"text/plain", p::Period) = print(io, p)
 Base.zero(::Union{Type{P},P}) where {P<:Period} = P(0)
 Base.one(::Union{Type{P},P}) where {P<:Period} = 1  # see #16116
 Base.typemin(::Type{P}) where {P<:Period} = P(typemin(Int64))

stdlib/Dates/test/io.jl

@@ -5,9 +5,61 @@ module IOTests
 using Test
 using Dates
 
+@testset "string/show representation of Period" begin
+    @test string(Dates.Year(2018)) == "2018 years"
+    @test sprint(show, Dates.Year(2018)) == "Dates.Year(2018)"
+    @test sprint(print, Dates.Year(2018)) == "2018 years"
+    @test repr(Dates.Year(2018)) == "Dates.Year(2018)"
+
+    @test string(Dates.Month(12)) == "12 months"
+    @test sprint(show, Dates.Month(12)) == "Dates.Month(12)"
+    @test sprint(print, Dates.Month(12)) == "12 months"
+    @test repr(Dates.Month(12)) == "Dates.Month(12)"
+
+    @test string(Dates.Week(4)) == "4 weeks"
+    @test sprint(show, Dates.Week(4)) == "Dates.Week(4)"
+    @test sprint(print, Dates.Week(4)) == "4 weeks"
+    @test repr(Dates.Week(4)) == "Dates.Week(4)"
+
+    @test string(Dates.Day(12)) == "12 days"
+    @test sprint(show, Dates.Day(12)) == "Dates.Day(12)"
+    @test sprint(print,Dates.Day(12)) == "12 days"
+    @test repr(Dates.Day(12)) == "Dates.Day(12)"
+
+    @test string(Dates.Hour(12)) == "12 hours"
+    @test sprint(show, Dates.Hour(12)) == "Dates.Hour(12)"
+    @test sprint(print,Dates.Hour(12)) == "12 hours"
+    @test repr(Dates.Hour(12)) == "Dates.Hour(12)"
+
+    @test string(Dates.Minute(12)) == "12 minutes"
+    @test sprint(show, Dates.Minute(12)) == "Dates.Minute(12)"
+    @test sprint(print,Dates.Minute(12)) == "12 minutes"
+    @test repr(Dates.Minute(12)) == "Dates.Minute(12)"
+
+    @test string(Dates.Second(12)) == "12 seconds"
+    @test sprint(show, Dates.Second(12)) == "Dates.Second(12)"
+    @test sprint(print,Dates.Second(12)) == "12 seconds"
+    @test repr(Dates.Second(12)) == "Dates.Second(12)"
+
+    @test string(Dates.Millisecond(12)) == "12 milliseconds"
+    @test sprint(show, Dates.Millisecond(12)) == "Dates.Millisecond(12)"
+    @test sprint(print,Dates.Millisecond(12)) == "12 milliseconds"
+    @test repr(Dates.Millisecond(12)) == "Dates.Millisecond(12)"
+
+    @test string(Dates.Microsecond(12)) == "12 microseconds"
+    @test sprint(show, Dates.Microsecond(12)) == "Dates.Microsecond(12)"
+    @test sprint(print,Dates.Microsecond(12)) == "12 microseconds"
+    @test repr(Dates.Microsecond(12)) == "Dates.Microsecond(12)"
+
+    @test string(Dates.Nanosecond(12)) == "12 nanoseconds"
+    @test sprint(show, Dates.Nanosecond(12)) == "Dates.Nanosecond(12)"
+    @test sprint(print,Dates.Nanosecond(12)) == "12 nanoseconds"
+    @test repr(Dates.Nanosecond(12)) == "Dates.Nanosecond(12)"
+end
+
 @testset "string/show representation of Date" begin
     @test string(Dates.Date(1, 1, 1)) == "0001-01-01" # January 1st, 1 AD/CE
-    @test sprint(show, Dates.Date(1, 1, 1)) == "Date(1, 1, 1)"
+    @test sprint(show, Dates.Date(1, 1, 1)) == "Dates.Date(1, 1, 1)"
     @test string(Dates.Date(0, 12, 31)) == "0000-12-31" # December 31, 1 BC/BCE
     @test Dates.Date(1, 1, 1) - Dates.Date(0, 12, 31) == Dates.Day(1)
     @test Dates.Date(Dates.UTD(-306)) == Dates.Date(0, 2, 29)
@@ -16,7 +68,7 @@ using Dates
     @test string(Dates.Date(-1000000, 1, 1)) == "-1000000-01-01"
     @test string(Dates.Date(1000000, 1, 1)) == "1000000-01-01"
     @test string(Dates.DateTime(2000, 1, 1, 0, 0, 0, 1)) == "2000-01-01T00:00:00.001"
-    @test sprint(show, Dates.DateTime(2000, 1, 1, 0, 0, 0, 1)) == "DateTime(2000, 1, 1, 0, 0, 0, 1)"
+    @test sprint(show, Dates.DateTime(2000, 1, 1, 0, 0, 0, 1)) == "Dates.DateTime(2000, 1, 1, 0, 0, 0, 1)"
     @test string(Dates.DateTime(2000, 1, 1, 0, 0, 0, 2)) == "2000-01-01T00:00:00.002"
     @test string(Dates.DateTime(2000, 1, 1, 0, 0, 0, 500)) == "2000-01-01T00:00:00.5"
     @test string(Dates.DateTime(2000, 1, 1, 0, 0, 0, 998)) == "2000-01-01T00:00:00.998"