# Following work by @jiahao, we compute character widths using a combination of # * character category # * UAX 11: East Asian Width # * a few exceptions as needed # Adapted from http://nbviewer.ipython.org/gist/jiahao/07e8b08bf6d8671e9734 # # We used to also use data from GNU Unifont, but that has proven unreliable # and unlikely to match widths assumed by terminals. # # Requires Julia (obviously) and FontForge. ############################################################################# 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) # utf8proc category constants (must match h) const UTF8PROC_CATEGORY_CN = 0 const UTF8PROC_CATEGORY_LU = 1 const UTF8PROC_CATEGORY_LL = 2 const UTF8PROC_CATEGORY_LT = 3 const UTF8PROC_CATEGORY_LM = 4 const UTF8PROC_CATEGORY_LO = 5 const UTF8PROC_CATEGORY_MN = 6 const UTF8PROC_CATEGORY_MC = 7 const UTF8PROC_CATEGORY_ME = 8 const UTF8PROC_CATEGORY_ND = 9 const UTF8PROC_CATEGORY_NL = 10 const UTF8PROC_CATEGORY_NO = 11 const UTF8PROC_CATEGORY_PC = 12 const UTF8PROC_CATEGORY_PD = 13 const UTF8PROC_CATEGORY_PS = 14 const UTF8PROC_CATEGORY_PE = 15 const UTF8PROC_CATEGORY_PI = 16 const UTF8PROC_CATEGORY_PF = 17 const UTF8PROC_CATEGORY_PO = 18 const UTF8PROC_CATEGORY_SM = 19 const UTF8PROC_CATEGORY_SC = 20 const UTF8PROC_CATEGORY_SK = 21 const UTF8PROC_CATEGORY_SO = 22 const UTF8PROC_CATEGORY_ZS = 23 const UTF8PROC_CATEGORY_ZL = 24 const UTF8PROC_CATEGORY_ZP = 25 const UTF8PROC_CATEGORY_CC = 26 const UTF8PROC_CATEGORY_CF = 27 const UTF8PROC_CATEGORY_CS = 28 const UTF8PROC_CATEGORY_CO = 29 ############################################################################# # Use a default width of 1 for all character categories that are # letter/symbol/number-like, as well as for unassigned/private-use chars. # This can be overriden by 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_CATEGORY_MN) push!(zerowidth, UTF8PROC_CATEGORY_MC) push!(zerowidth, UTF8PROC_CATEGORY_ME) push!(zerowidth, UTF8PROC_CATEGORY_SK) push!(zerowidth, UTF8PROC_CATEGORY_ZL) push!(zerowidth, UTF8PROC_CATEGORY_ZP) push!(zerowidth, UTF8PROC_CATEGORY_CC) push!(zerowidth, UTF8PROC_CATEGORY_CF) push!(zerowidth, UTF8PROC_CATEGORY_CS) for c in 0x0000:0x110000 if catcode(c) ∉ zerowidth CharWidths[c] = 1 end end ############################################################################# # Widths from UAX #11: East Asian Width # .. these take precedence for all codepoints # listed explicitly as wide/full/narrow/half-width for line in readlines(open("EastAsianWidth.txt")) #Strip comments (isempty(line) || 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" 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 # (some of these, like U+0601, can have a width in some cases # but normally act like prepended combining marks. U+fff9 etc # are also odd, but have zero width in typical terminal contexts) if cat==UTF8PROC_CATEGORY_CF 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_CATEGORY_MN CharWidths[c]=0 end # We also assign width of one to unassigned and private-use # codepoints (Unifont includes ConScript Unicode Registry PUA fonts, # but since these are nonstandard it seems questionable to use Unifont metrics; # if they are printed as the replacement character U+FFFD they will have width 1). if cat==UTF8PROC_CATEGORY_CO || cat==UTF8PROC_CATEGORY_CN CharWidths[c]=1 end # for some reason, Unifont has width-2 glyphs for ASCII control chars if cat==UTF8PROC_CATEGORY_CC CharWidths[c]=0 end end #Soft hyphen is typically printed as a hyphen (-) in terminals. CharWidths[0x00ad]=1 #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 ############################################################################# # Output (to a file or pipe) for processing by data_generator.rb, # encoded as a sequence of intervals. firstc = 0x000000 lastv = 0 uhex(c) = uppercase(string(c,base=16,pad=4)) for c in 0x0000:0x110000 global firstc, lastv 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