Fix String -> AbstractString (#35)

* Fix String -> AbstractString

* Fix docs

Project.toml

@@ -1,7 +1,7 @@
 name = "UnitfulRecipes"
 uuid = "42071c24-d89e-48dd-8a24-8a12d9b8861f"
 authors = ["Benoit Pasquier", "Jan Weidner"]
-version = "1.0.0"
+version = "1.0.1"
 
 [deps]
 RecipesBase = "3cdcf5f2-1ef4-517c-9805-6587b60abb01"

docs/lit/examples/2_Plots.jl

@@ -39,7 +39,7 @@ y = rand(20, 3)*u"W"
 x = (1:size(y,1))*u"Hz"
 plot(x, y, xlabel="XLABEL", xlims=(-5, 30), xflip=true, xticks=0:2:20, background_color=RGB(0.2, 0.2, 0.2), leg=false)
 hline!(mean(y, dims=1) + rand(1, 3)*u"W", line=(4, :dash, 0.6, [:lightgreen :green :darkgreen]))
-vline!([5, 10]*u"W") # this is a current Plots v1.0.3 bug. Should be Hz
+vline!([5, 10]*u"Hz")
 title!("TITLE")
 yaxis!("YLABEL", :log10)
 

src/UnitfulRecipes.jl

@@ -114,11 +114,11 @@ Label string containing unit information
 =======================================#
 
 abstract type AbstractProtectedString <: AbstractString end
-struct ProtectedString <: AbstractProtectedString
-    content::String
+struct ProtectedString{S} <: AbstractProtectedString
+    content::S
 end
-struct UnitfulString{U} <: AbstractProtectedString
-    content::String
+struct UnitfulString{S,U} <: AbstractProtectedString
+    content::S
     unit::U
 end
 # Minimum required AbstractString interface to work with Plots
@@ -161,9 +161,9 @@ append_unit_if_needed!(attr, key, label::UnitfulString, u) = nothing
 function append_unit_if_needed!(attr, key, label::Nothing, u)
     attr[key] = UnitfulString(string(u), u)
 end
-function append_unit_if_needed!(attr, key, label::String, u)
+function append_unit_if_needed!(attr, key, label::S, u) where {S <: AbstractString}
     if label ≠ ""
-        attr[key] = UnitfulString(string(label, " (", u, ")"), u)
+        attr[key] = UnitfulString(S(string(label, " (", u, ")")), u)
     end
 end