add Printf support (#201)

* add Printf support

* fix test for older Julia versions

Author: aplavin

Project.toml

@@ -8,11 +8,13 @@ RecipesBase = "3cdcf5f2-1ef4-517c-9805-6587b60abb01"
 Statistics = "10745b16-79ce-11e8-11f9-7d13ad32a3b2"
 
 [weakdeps]
+Printf = "de0858da-6303-5e67-8744-51eddeeeb8d7"
 Random = "9a3f8284-a2c9-5f02-9a11-845980a1fd5c"
 RecipesBase = "3cdcf5f2-1ef4-517c-9805-6587b60abb01"
 Statistics = "10745b16-79ce-11e8-11f9-7d13ad32a3b2"
 
 [extensions]
+IntervalSetsPrintfExt = "Printf"
 IntervalSetsRandomExt = "Random"
 IntervalSetsRecipesBaseExt = "RecipesBase"
 IntervalSetsStatisticsExt = "Statistics"
@@ -22,6 +24,7 @@ Aqua = "0.8"
 Dates = "1"
 OffsetArrays = "1"
 Plots = "1"
+Printf = "1"
 Random = "1"
 RecipesBase = "1"
 Statistics = "1"
@@ -34,11 +37,12 @@ Aqua = "4c88cf16-eb10-579e-8560-4a9242c79595"
 Dates = "ade2ca70-3891-5945-98fb-dc099432e06a"
 OffsetArrays = "6fe1bfb0-de20-5000-8ca7-80f57d26f881"
 Plots = "91a5bcdd-55d7-5caf-9e0b-520d859cae80"
+Printf = "de0858da-6303-5e67-8744-51eddeeeb8d7"
 Random = "9a3f8284-a2c9-5f02-9a11-845980a1fd5c"
 RecipesBase = "3cdcf5f2-1ef4-517c-9805-6587b60abb01"
 Statistics = "10745b16-79ce-11e8-11f9-7d13ad32a3b2"
 Test = "8dfed614-e22c-5e08-85e1-65c5234f0b40"
 Unitful = "1986cc42-f94f-5a68-af5c-568840ba703d"
 
 [targets]
-test = ["Aqua", "Dates", "Test", "Plots", "Random", "RecipesBase", "OffsetArrays", "Statistics", "Unitful"]
+test = ["Aqua", "Dates", "Test", "Plots", "Printf", "Random", "RecipesBase", "OffsetArrays", "Statistics", "Unitful"]

ext/IntervalSetsPrintfExt.jl

@@ -0,0 +1,30 @@
+module IntervalSetsPrintfExt
+
+using Printf
+using IntervalSets
+using IntervalSets: _show_suffix
+
+INTERVAL_SEPARATOR = " .. "
+
+Printf.plength(f::Printf.Spec{<:Printf.Ints}, x::Interval) =
+    Printf.plength(f, leftendpoint(x)) + Printf.plength(f, rightendpoint(x)) +
+    ncodeunits(INTERVAL_SEPARATOR) + ncodeunits(_show_suffix(x))
+
+# separate methods for disambiguation
+Printf.fmt(buf, pos, arg::Interval, spec::Printf.Spec{<:Printf.Floats}) = _fmt(buf, pos, arg, spec)
+Printf.fmt(buf, pos, arg::Interval, spec::Printf.Spec{<:Printf.Ints}) = _fmt(buf, pos, arg, spec)
+
+function _fmt(buf, pos, arg, spec)
+    pos = Printf.fmt(buf, pos, leftendpoint(arg), spec)
+    buf[pos:pos+ncodeunits(INTERVAL_SEPARATOR)-1] .= codeunits(INTERVAL_SEPARATOR)
+    pos += ncodeunits(INTERVAL_SEPARATOR)
+    pos = Printf.fmt(buf, pos, rightendpoint(arg), spec)
+
+    suf = _show_suffix(arg)
+    buf[pos:pos+ncodeunits(suf)-1] .= codeunits(suf)
+    pos += ncodeunits(suf)
+
+    return pos
+end
+
+end

src/interval.jl

@@ -156,10 +156,12 @@ julia> 3 ± 2
 ±(x, y) = ClosedInterval(x - y, x + y)
 ±(x::CartesianIndex, y::CartesianIndex) = ClosedInterval(x-y, x+y)
 
-show(io::IO, I::ClosedInterval) = print(io, leftendpoint(I), " .. ", rightendpoint(I))
-show(io::IO, I::OpenInterval) = print(io, leftendpoint(I), " .. ", rightendpoint(I), " (open)")
-show(io::IO, I::Interval{:open,:closed}) = print(io, leftendpoint(I), " .. ", rightendpoint(I), " (open-closed)")
-show(io::IO, I::Interval{:closed,:open}) = print(io, leftendpoint(I), " .. ", rightendpoint(I), " (closed-open)")
+_show_suffix(::ClosedInterval) = ""
+_show_suffix(::OpenInterval) = " (open)"
+_show_suffix(::Interval{:open,:closed}) = " (open-closed)"
+_show_suffix(::Interval{:closed,:open}) = " (closed-open)"
+
+show(io::IO, I::Interval) = print(io, leftendpoint(I), " .. ", rightendpoint(I), _show_suffix(I))
 
 # The following are not typestable for mixed endpoint types
 _left_intersect_type(::Type{Val{:open}}, ::Type{Val{L2}}, a1, a2) where L2 = a1 < a2 ? (a2,L2) : (a1,:open)

test/runtests.jl

@@ -6,6 +6,7 @@ import Statistics: mean
 using Random
 using Unitful
 using Plots
+using Printf
 
 import IntervalSets: Domain, endpoints, closedendpoints, TypedEndpointsInterval
 
@@ -443,6 +444,15 @@ struct IncompleteInterval <: AbstractInterval{Int} end
         @test_throws MethodError 2 in I
     end
 
+    VERSION ≥ v"1.9" && @testset "stringify" begin
+        @test string(0..1) == "0 .. 1"
+        @test string(iv"[0,1)") == "0 .. 1 (closed-open)"
+        @test @sprintf("%d", 0..1) == "0 .. 1"
+        @test @sprintf("%.2f", 0..1) == "0.00 .. 1.00"
+        @test @sprintf("%.2f", iv"[0,1)") == "0.00 .. 1.00 (closed-open)"
+        @test @sprintf("%.2f", 0u"m"..1u"m") == "0.00 m .. 1.00 m"
+    end
+
     include("base_methods.jl")
     include("setoperations.jl")
     include("findall.jl")