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# Following work by @jiahao, we compute character widths using a combination of
# * advance widths from GNU Unifont (advance width 512 = 1 en)
# * UAX 11: East Asian Width
# * a few exceptions as needed
# Adapted from http://nbviewer.ipython.org/gist/jiahao/07e8b08bf6d8671e9734
#
# Requires Julia (obviously) and FontForge.
#############################################################################
# Julia 0.3/0.4 compatibility (taken from Compat package)
if VERSION < v"0.4.0-dev+1387"
typealias AbstractString String
end
if VERSION < v"0.4.0-dev+1419"
const UInt32 = Uint32
end
if VERSION < v"0.4.0-dev+3874"
Base.parse{T<:Integer}(::Type{T}, s::AbstractString) = parseint(T, s)
end
CharWidths = Dict{Int,Int}()
#############################################################################
# Use ../libutf8proc for category codes, rather than the one in Julia,
# to minimize bootstrapping complexity when a new version of Unicode comes out.
catcode(c) = ccall((:utf8proc_category,"../libutf8proc"), Cint, (Int32,), c)
# use Base.UTF8proc module to get category codes constants, since
# we won't change these in utf8proc.
import Base.UTF8proc
#############################################################################
# Use a default width of 1 for all character categories that are
# letter/symbol/number-like. This can be overriden by Unifont or UAX 11
# below, but provides a useful nonzero fallback for new codepoints when
# a new Unicode version has been released but Unifont hasn't been updated yet.
zerowidth = Set{Int}() # categories that may contain zero-width chars
push!(zerowidth, UTF8proc.UTF8PROC_CATEGORY_CN)
push!(zerowidth, UTF8proc.UTF8PROC_CATEGORY_MN)
push!(zerowidth, UTF8proc.UTF8PROC_CATEGORY_MC)
push!(zerowidth, UTF8proc.UTF8PROC_CATEGORY_ME)
push!(zerowidth, UTF8proc.UTF8PROC_CATEGORY_SK)
push!(zerowidth, UTF8proc.UTF8PROC_CATEGORY_ZS)
push!(zerowidth, UTF8proc.UTF8PROC_CATEGORY_ZL)
push!(zerowidth, UTF8proc.UTF8PROC_CATEGORY_ZP)
push!(zerowidth, UTF8proc.UTF8PROC_CATEGORY_CC)
push!(zerowidth, UTF8proc.UTF8PROC_CATEGORY_CF)
push!(zerowidth, UTF8proc.UTF8PROC_CATEGORY_CS)
push!(zerowidth, UTF8proc.UTF8PROC_CATEGORY_CO)
for c in 0x0000:0x110000
if catcode(c) zerowidth
CharWidths[c] = 1
end
end
#############################################################################
# Widths from GNU Unifont
#Read sfdfile for character widths
function parsesfd(filename::AbstractString, CharWidths::Dict{Int,Int}=Dict{Int,Int}())
state=:seekchar
lineno = 0
codepoint = width = nothing
for line in readlines(open(filename))
lineno += 1
if state==:seekchar #StartChar: nonmarkingreturn
if contains(line, "StartChar: ")
codepoint = nothing
width = nothing
state = :readdata
end
elseif state==:readdata #Encoding: 65538 -1 2, Width: 1024
contains(line, "Encoding:") && (codepoint = parse(Int, split(line)[3]))
contains(line, "Width:") && (width = parse(Int, split(line)[2]))
if codepoint!=nothing && width!=nothing && codepoint >= 0
w=div(width, 512) # 512 units to the en
if w > 0
# only add nonzero widths, since (1) the default is zero
# and (2) this circumvents some apparent bugs in Unifont
# (https://savannah.gnu.org/bugs/index.php?45395)
CharWidths[codepoint] = w
end
state = :seekchar
end
end
end
CharWidths
end
CharWidths=parsesfd("unifont.sfd", CharWidths)
CharWidths=parsesfd("unifont_upper.sfd", CharWidths)
#############################################################################
# Widths from UAX #11: East Asian Width
# .. these take precedence over the Unifont width for all codepoints
# listed explicitly as wide/full/narrow/half-width
for line in readlines(open("EastAsianWidth.txt"))
#Strip comments
line[1] == '#' && continue
precomment = split(line, '#')[1]
#Parse code point range and width code
tokens = split(precomment, ';')
length(tokens) >= 2 || continue
charrange = tokens[1]
width = strip(tokens[2])
#Parse code point range into Julia UnitRange
rangetokens = split(charrange, "..")
charstart = parse(UInt32, "0x"*rangetokens[1])
charend = parse(UInt32, "0x"*rangetokens[length(rangetokens)>1 ? 2 : 1])
#Assign widths
for c in charstart:charend
if width=="W" || width=="F" # wide or full
CharWidths[c]=2
elseif width=="Na"|| width=="H" # narrow or half
CharWidths[c]=1
end
end
end
#############################################################################
# A few exceptions to the above cases, found by manual comparison
# to other wcwidth functions and similar checks.
for c in keys(CharWidths)
cat = catcode(c)
# make sure format control character (category Cf) have width 0,
# except for the Arabic characters 0x06xx (see unicode std 6.2, sec. 8.2)
if cat==UTF8proc.UTF8PROC_CATEGORY_CF && c [0x0601,0x0602,0x0603,0x06dd]
CharWidths[c]=0
end
# Unifont has nonzero width for a number of non-spacing combining
# characters, e.g. (in 7.0.06): f84,17b4,17b5,180b,180d,2d7f, and
# the variation selectors
if cat==UTF8proc.UTF8PROC_CATEGORY_MN
CharWidths[c]=0
end
# We also assign width of zero to unassigned and private-use
# codepoints (Unifont includes ConScript Unicode Registry PUA fonts,
# but since these are nonstandard it seems questionable to recognize them).
if cat==UTF8proc.UTF8PROC_CATEGORY_CO || cat==UTF8proc.UTF8PROC_CATEGORY_CN
CharWidths[c]=0
end
# for some reason, Unifont has width-2 glyphs for ASCII control chars
if cat==UTF8proc.UTF8PROC_CATEGORY_CC
CharWidths[c]=0
end
end
#By definition, should have zero width (on the same line)
#0x002028 '
' category: Zl name: LINE SEPARATOR/
#0x002029 '
' category: Zp name: PARAGRAPH SEPARATOR/
CharWidths[0x2028]=0
CharWidths[0x2029]=0
#By definition, should be narrow = width of 1 en space
#0x00202f ' ' category: Zs name: NARROW NO-BREAK SPACE/
CharWidths[0x202f]=1
#By definition, should be wide = width of 1 em space
#0x002001 ' ' category: Zs name: EM QUAD/
#0x002003 ' ' category: Zs name: EM SPACE/
CharWidths[0x2001]=2
CharWidths[0x2003]=2
#############################################################################
# Output (to a file or pipe) for processing by data_generator.rb
# ... don't bother to output zero widths since that will be the default.
firstc = 0x000000
lastv = 0
uhex(c) = uppercase(hex(c,4))
for c in 0x0000:0x110000
v = get(CharWidths, c, 0)
if v != lastv || c == 0x110000
v < 4 || error("invalid charwidth $v for $c")
if firstc+1 < c
println(uhex(firstc), "..", uhex(c-1), "; ", lastv)
else
println(uhex(firstc), "; ", lastv)
end
firstc = c
lastv = v
end
end