add type assertions (#144)

src/color_utils.jl

@@ -5,22 +5,22 @@
 # background color and a short list of seed colors
 
 # here are some magic constants that could be changed if you really want
-const _lightness_darkbg = [80.0]
-const _lightness_lightbg = [60.0]
-const _lch_c_const = [60]
+const _lightness_darkbg = Ref(80.0)
+const _lightness_lightbg = Ref(60.0)
+const _lch_c_const = Ref(60)
 
 adjust_lch(color, l, c) = convert(RGBA{Float64}, LCHab(l, c, convert(LCHab, color).h))
 
 function lightness_from_background(bgcolor)
     bglight = convert(LCHab, bgcolor).l
-    bglight < 50.0 ? _lightness_darkbg[1] : _lightness_lightbg[1]
+    bglight < 50.0 ? _lightness_darkbg[] : _lightness_lightbg[]
 end
 
 function generate_colorscheme(
     bgcolor = plot_color(:white);
     color_bases = plot_color([colorant"steelblue", colorant"orangered"]),
     lightness = lightness_from_background(bgcolor),
-    chroma = _lch_c_const[1],
+    chroma = _lch_c_const[],
     n = 17,
 )
     seed_colors = vcat(bgcolor, map(c -> adjust_lch(c, lightness, chroma), color_bases))
@@ -37,7 +37,7 @@ end
 
 # ----------------------------------------------------------------------------------
 
-function getpctrange(n::Int)
+function getpctrange(n::Integer)
     n > 0 || error()
     n == 1 && return zeros(1)
     zs = [0.0, 1.0]
@@ -52,12 +52,12 @@ function getpctrange(n::Int)
                 widestj = j
             end
         end
-        push!(zs, sorted[widestj] + 0.5 * diffs[widestj])
+        push!(zs, sorted[widestj] + 0.5diffs[widestj])
     end
     zs
 end
 
-function get_zvalues(n::Int)
+function get_zvalues(n::Integer)
     offsets = getpctrange(ceil(Int, n / 4) + 1) / 4
     offsets = vcat(offsets[1], offsets[3:end])
     zvalues = Float64[]
@@ -79,25 +79,23 @@ end
 lighten(c, v = 0.3) = darken(c, -v)
 
 # borrowed from http://stackoverflow.com/a/1855903:
-lightness_level(c::Colorant) = 0.299 * red(c) + 0.587 * green(c) + 0.114 * blue(c)
+lightness_level(c::Colorant) = 0.299red(c) + 0.587green(c) + 0.114blue(c)
 
-isdark(c::Colorant) = lightness_level(c) < 0.5
-islight(c::Colorant) = !isdark(c)
+isdark(c::Colorant)::Bool = lightness_level(c) < 0.5
+islight(c::Colorant)::Bool = !isdark(c)
 
 Base.convert(::Type{RGB}, h::Unsigned) =
     RGB([(x & 0x0000FF) / 0xFF for x in (h >> 16, h >> 8, h)]...)
 
-make255(x) = round(Int, 255 * x)
+make255(x)::Int = round(Int, 255 * x)
 
 rgb_string(c::Colorant) =
     @sprintf("rgb(%d, %d, %d)", make255(red(c)), make255(green(c)), make255(blue(c)))
 
-function rgba_string(c::Colorant)
-    @sprintf(
-        "rgba(%d, %d, %d, %1.3f)",
-        make255(red(c)),
-        make255(green(c)),
-        make255(blue(c)),
-        alpha(c)
-    )
-end
+rgba_string(c::Colorant) = @sprintf(
+    "rgba(%d, %d, %d, %1.3f)",
+    make255(red(c)),
+    make255(green(c)),
+    make255(blue(c)),
+    alpha(c)
+)

src/colors.jl

@@ -9,7 +9,9 @@ plot_color(s::Symbol) =
     catch e
         is_colorscheme(s) ? cgrad(s) : rethrow(e)
     end
-plot_color(b::Bool) = b ? error("plot_color(true) not allowed.") : invisible()
+plot_color(b::Val{true}) = error("plot_color(true) not allowed.")
+plot_color(b::Val{false}) = invisible()
+plot_color(b::Bool) = plot_color(Val(b))
 plot_color(::Nothing) = invisible()
 plot_color(c::Colorant) = convert(RGBA{Float64}, c)
 # plot_color(cs::AbstractVector) = RGBA{Float64}[plot_color(c) for c in cs]

src/ticks.jl

@@ -1,4 +1,4 @@
-const _logScales = [:ln, :log2, :log10]
+const _logScales = (:ln, :log2, :log10)
 const _logScaleBases = Dict(:ln => ℯ, :log2 => 2.0, :log10 => 10.0)
 
 # NOTE: This file was moved from Gadfly.jl, and the original author is Daniel Jones (@dcjones)