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Modify strictness of color parser (Fixes #360)
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- Modify white space handling
- Add error message about 8-digit or 4-digit hex notation
- Add support for some CSS4 notations
- Add tests
- Speed up parsing averagely
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@kimikage
kimikage committed Nov 27, 2019
1 parent 0ceb396 commit 1bc194e
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Showing 2 changed files with 98 additions and 57 deletions.
114 changes: 66 additions & 48 deletions src/parse.jl
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Original file line number Diff line number Diff line change
Expand Up @@ -5,19 +5,20 @@ include("names_data.jl")
# Color Parsing
# -------------

const col_pat_hex1 = r"(#|0x)([[:xdigit:]])([[:xdigit:]])([[:xdigit:]])"
const col_pat_hex2 = r"(#|0x)([[:xdigit:]]{2})([[:xdigit:]]{2})([[:xdigit:]]{2})"
const col_pat_rgb = r"rgb\((\d+%?),(\d+%?),(\d+%?)\)"
const col_pat_hsl = r"hsl\((\d+%?),(\d+%?),(\d+%?)\)"
const col_pat_rgba = r"rgba\((\d+%?),(\d+%?),(\d+%?),(\d+(?:\.\d*)?%?)\)"
const col_pat_hsla = r"hsla\((\d+%?),(\d+%?),(\d+%?),(\d+(?:\.\d*)?%?)\)"
const col_pat_hex = r"^\s*(#|0x)([[:xdigit:]]{3,8})\s*$"
const col_pat_rgb = r"^\s*rgb\(\s*(\d+%?)\s*[,\s]\s*(\d+%?)\s*[,\s]\s*(\d+%?)\s*\)\s*$"
const col_pat_hsl = r"^\s*hsl\(\s*(\d+%?)\s*[,\s]\s*(\d+%?)\s*[,\s]\s*(\d+%?)\s*\)\s*$"
const col_pat_rgba = r"^\s*rgba?\(\s*(\d+%?)\s*[,\s]\s*(\d+%?)\s*[,\s]\s*(\d+%?)\s*[,/]\s*((?:\d+|(?=\.\d))(?:\.\d*)?%?)\s*\)\s*$"
const col_pat_hsla = r"^\s*hsla?\(\s*(\d+%?)\s*[,\s]\s*(\d+%?)\s*[,\s]\s*(\d+%?)\s*[,/]\s*((?:\d+|(?=\.\d))(?:\.\d*)?%?)\s*\)\s*$"

chop1(x) = SubString(x, 1, lastindex(x) - 1) # `chop` is slightly slow

# Parse a number used in the "rgb()" or "hsl()" color.
function parse_rgb(num::AbstractString)
if num[end] == '%'
return clamp(parse(Int, num[1:end-1], base=10) / 100, 0, 1)
return N0f8(clamp(parse(Int, chop1(num), base=10) / 100, 0, 1))
else
return clamp(parse(Int, num, base=10) / 255, 0, 1)
return reinterpret(N0f8, UInt8(clamp(parse(Int, num, base=10), 0, 255)))
end
end

Expand All @@ -33,78 +34,95 @@ function parse_hsl_sl(num::AbstractString)
if num[end] != '%'
error("saturation and lightness must end in %")
else
return parse(Int, num[1:end-1], base=10) / 100
return parse(Int, chop1(num), base=10) / 100
end
end

# Parse a number used in the alpha field of "rgba()" and "hsla()".
function parse_alpha_num(num::AbstractString)
if num[end] == '%'
return parse(Int, num[1:end-1]) / 100
return parse(Int, chop1(num), base=10) / 100f0
else
# `parse(Float32, num)` is somewhat slow on Windows(x86_64-w64-mingw32).
# However, the following has the opposite effect on Linux.
# m = match(r"0?\.(\d{1,9})", num)
# if m != nothing
# d = m.captures[1]
# return parse(Int, d, base=10) / Float32(exp10(length(d)))
# end
return parse(Float32, num)
end
end

function _parse_colorant(desc::AbstractString)
desc_ = replace(desc, " " => "")
mat = match(col_pat_hex2, desc_)
mat = match(col_pat_hex, desc)
if mat != nothing
return RGB{N0f8}(parse(Int, mat.captures[2], base=16) / 255,
parse(Int, mat.captures[3], base=16) / 255,
parse(Int, mat.captures[4], base=16) / 255)
prefix = mat.captures[1]
len = length(mat.captures[2])
digits = parse(UInt32, mat.captures[2], base=16)
if len == 6
return convert(RGB{N0f8}, reinterpret(RGB24, digits))
elseif len == 3
return RGB{N0f8}(reinterpret(N0f8, UInt8(((digits&0xF00)>>8) * 17)),
reinterpret(N0f8, UInt8(((digits&0x0F0)>>4) * 17)),
reinterpret(N0f8, UInt8(((digits&0x00F)) * 17)))
elseif len == 8 || len == 4
error("8-digit and 4-digit hex notations are not supported yet.")
end
end

mat = match(col_pat_hex1, desc_)
if mat != nothing
return RGB{N0f8}(parse(Int, mat.captures[2], base=16) / 15,
parse(Int, mat.captures[3], base=16) / 15,
parse(Int, mat.captures[4], base=16) / 15)
end

mat = match(col_pat_rgb, desc_)
mat = match(col_pat_rgb, desc)
if mat != nothing
return RGB{N0f8}(parse_rgb(mat.captures[1]),
parse_rgb(mat.captures[2]),
parse_rgb(mat.captures[3]))
parse_rgb(mat.captures[2]),
parse_rgb(mat.captures[3]))
end

mat = match(col_pat_hsl, desc_)
mat = match(col_pat_hsl, desc)
if mat != nothing
return HSL{ColorTypes.eltype_default(HSL)}(parse_hsl_hue(mat.captures[1]),
parse_hsl_sl(mat.captures[2]),
parse_hsl_sl(mat.captures[3]))
T = ColorTypes.eltype_default(HSL)
return HSL{T}(parse_hsl_hue(mat.captures[1]),
parse_hsl_sl(mat.captures[2]),
parse_hsl_sl(mat.captures[3]))
end

mat = match(col_pat_rgba, desc_)
mat = match(col_pat_rgba, desc)
if mat != nothing
return RGBA{N0f8}(parse_rgb(mat.captures[1]),
parse_rgb(mat.captures[2]),
parse_rgb(mat.captures[3]),
parse_alpha_num(mat.captures[4]))
parse_rgb(mat.captures[2]),
parse_rgb(mat.captures[3]),
parse_alpha_num(mat.captures[4]))
end

mat = match(col_pat_hsla, desc_)
mat = match(col_pat_hsla, desc)
if mat != nothing
return HSLA{ColorTypes.eltype_default(HSLA)}(parse_hsl_hue(mat.captures[1]),
parse_hsl_sl(mat.captures[2]),
parse_hsl_sl(mat.captures[3]),
parse_alpha_num(mat.captures[4]))
T = ColorTypes.eltype_default(HSLA)
return HSLA{T}(parse_hsl_hue(mat.captures[1]),
parse_hsl_sl(mat.captures[2]),
parse_hsl_sl(mat.captures[3]),
parse_alpha_num(mat.captures[4]))
end


desc_ = lowercase(desc_)

if desc_ == "transparent"
return RGBA{N0f8}(0,0,0,0)
sdesc = strip(desc)
c = get(color_names, sdesc, nothing)
if c != nothing
return RGB{N0f8}(reinterpret(N0f8, UInt8(c[1])),
reinterpret(N0f8, UInt8(c[2])),
reinterpret(N0f8, UInt8(c[3])))
end
# since `lowercase` is slightly slow, it is applied only when needed
ldesc = lowercase(sdesc)
c = get(color_names, ldesc, nothing)
if c != nothing
return RGB{N0f8}(reinterpret(N0f8, UInt8(c[1])),
reinterpret(N0f8, UInt8(c[2])),
reinterpret(N0f8, UInt8(c[3])))
end

if !haskey(color_names, desc_)
error("Unknown color: ", desc)
if ldesc == "transparent"
return RGBA{N0f8}(0,0,0,0)
end

c = color_names[desc_]
return RGB{N0f8}(c[1] / 255, c[2] / 255, c[3] / 255)
error("Unknown color: ", desc)
end

# note: these exist to enable proper dispatch, since super(Colorant) == Any
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41 changes: 32 additions & 9 deletions test/parse.jl
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Original file line number Diff line number Diff line change
Expand Up @@ -4,23 +4,46 @@ using FixedPointNumbers
r8(x) = reinterpret(N0f8, x)

# Color parsing
# named-color
redN0f8 = parse(Colorant, "red")
@test colorant"red" == redN0f8
@test isa(redN0f8, RGB{N0f8})
@test redN0f8 == RGB(1,0,0)
@test parse(RGB{Float64}, "red") === RGB{Float64}(1,0,0)
@test isa(parse(HSV, "blue"), HSV)
@test parse(Colorant, "rgb(55,217,127)") === RGB{N0f8}(r8(0x37),r8(0xd9),r8(0x7f))
@test colorant"rgb(55,217,127)" === RGB{N0f8}(r8(0x37),r8(0xd9),r8(0x7f))
@test parse(Colorant, "rgba(55,217,127,0.5)") === RGBA{N0f8}(r8(0x37),r8(0xd9),r8(0x7f),0.5)
@test parse(Colorant, "rgb(55,217,127)") === RGB{N0f8}(r8(0x37),r8(0xd9),r8(0x7f))
@test parse(Colorant, "rgba(55,217,127,0.5)") === RGBA{N0f8}(r8(0x37),r8(0xd9),r8(0x7f),0.5)
@test parse(Colorant, "hsl(120, 100%, 50%)") === HSL{Float32}(120,1.0,.5)
@test colorant"hsl(120, 100%, 50%)" === HSL{Float32}(120,1.0,.5)
@test parse(RGB{N0f8}, "hsl(120, 100%, 50%)") === convert(RGB{N0f8}, HSL{Float32}(120,1.0,.5))
@test_throws ErrorException parse(Colorant, "hsl(120, 100, 50)")
@test_throws ErrorException parse(Colorant, "p ink")
@test parse(Colorant, "transparent") === RGBA{N0f8}(0,0,0,0)
@test parse(Colorant, "\nSeaGreen ") === RGB{N0f8}(r8(0x2E),r8(0x8B),r8(0x57))

# hex-color
@test parse(Colorant, "#D0FF58") === RGB(r8(0xD0),r8(0xFF),r8(0x58))
@test parse(Colorant, "0xd0ff58") === RGB(r8(0xD0),r8(0xFF),r8(0x58))
@test parse(Colorant, "#FB0") === RGB(r8(0xFF),r8(0xBB),r8(0x00))
@test_throws ErrorException parse(Colorant, "#FB0A")
@test_throws ErrorException parse(Colorant, "#BAD05")
@test_throws ErrorException parse(Colorant, "#BAD0007")
@test_throws ErrorException parse(Colorant, "#FFBB00AA") # not supported yet
@test_throws ErrorException parse(Colorant, "0xFFBB00AA") # not supported yet

# rgb()
@test parse(Colorant, "rgb(55,217,127)") === RGB{N0f8}(r8(0x37),r8(0xd9),r8(0x7f))
@test colorant" rgb( 55, 217, 127 ) " === RGB{N0f8}(r8(0x37),r8(0xd9),r8(0x7f))
@test parse(Colorant, "rgb(22%,85%,50%)") === RGB{N0f8}(r8(0x38),r8(0xd9),r8(0x80))
@test parse(Colorant, "rgba(55,217,127,0.5)") === RGBA{N0f8}(r8(0x37),r8(0xd9),r8(0x7f),0.5)
@test parse(Colorant, "rgb( 55,217,127,50%)") === RGBA{N0f8}(r8(0x37),r8(0xd9),r8(0x7f),0.5) # CSS Color Module Level 4
@test parse(Colorant, "rgb( 55 217 127 /.5)") === RGBA{N0f8}(r8(0x37),r8(0xd9),r8(0x7f),0.5) # CSS Color Module Level 4
@test parse(Colorant, "rgb(55, 85%, 50%)") === RGB{N0f8}(r8(0x37),r8(0xd9),r8(0x80)) # this is invalid according to CSS spec.
@test_throws ErrorException parse(Colorant, "rgb(21.6%,85%,50%)") # this is valid but not supported

# hsl()
@test parse(Colorant, "hsl(120, 100%, 50%)") === HSL{Float32}(120,1.0,.5)
@test colorant" hsl( 120, 100%, 50% ) " === HSL{Float32}(120,1.0,.5)
@test parse(RGB{N0f8},"hsl(120, 100%, 50%)") === convert(RGB{N0f8}, HSL{Float32}(120,1.0,.5))
@test_throws ErrorException parse(Colorant, "hsl(120, 100, 50)")
@test_throws ErrorException parse(Colorant, "hsl(120%,100%,50%)")
@test parse(Colorant, "hsla(120,50%,7%, .6)") === HSLA{Float32}(120,.5,.07,.6)
@test parse(Colorant, "hsl( 120,50%,7%,60%)") === HSLA{Float32}(120,.5,.07,.6) # CSS Color Module Level 4
@test parse(Colorant, "hsl( 120 50% 7% / 1)") === HSLA{Float32}(120,.5,.07, 1) # CSS Color Module Level 4

@test parse(Colorant, :red) === colorant"red"
@test parse(Colorant, colorant"red") === colorant"red"
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