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-rw-r--r--lualibs-unicode.lua193
1 files changed, 193 insertions, 0 deletions
diff --git a/lualibs-unicode.lua b/lualibs-unicode.lua
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--- /dev/null
+++ b/lualibs-unicode.lua
@@ -0,0 +1,193 @@
+if not modules then modules = { } end modules ['l-unicode'] = {
+ version = 1.001,
+ comment = "companion to luat-lib.mkiv",
+ author = "Hans Hagen, PRAGMA-ADE, Hasselt NL",
+ copyright = "PRAGMA ADE / ConTeXt Development Team",
+ license = "see context related readme files"
+}
+
+if not unicode then
+
+ unicode = { utf8 = { } }
+
+ local floor, char = math.floor, string.char
+
+ function unicode.utf8.utfchar(n)
+ if n < 0x80 then
+ return char(n)
+ elseif n < 0x800 then
+ return char(0xC0 + floor(n/0x40)) .. char(0x80 + (n % 0x40))
+ elseif n < 0x10000 then
+ return char(0xE0 + floor(n/0x1000)) .. char(0x80 + (floor(n/0x40) % 0x40)) .. char(0x80 + (n % 0x40))
+ elseif n < 0x40000 then
+ return char(0xF0 + floor(n/0x40000)) .. char(0x80 + floor(n/0x1000)) .. char(0x80 + (floor(n/0x40) % 0x40)) .. char(0x80 + (n % 0x40))
+ else -- wrong:
+ -- return char(0xF1 + floor(n/0x1000000)) .. char(0x80 + floor(n/0x40000)) .. char(0x80 + floor(n/0x1000)) .. char(0x80 + (floor(n/0x40) % 0x40)) .. char(0x80 + (n % 0x40))
+ return "?"
+ end
+ end
+
+end
+
+utf = utf or unicode.utf8
+
+local concat, utfchar, utfgsub = table.concat, utf.char, utf.gsub
+local char, byte, find, bytepairs = string.char, string.byte, string.find, string.bytepairs
+
+-- 0 EF BB BF UTF-8
+-- 1 FF FE UTF-16-little-endian
+-- 2 FE FF UTF-16-big-endian
+-- 3 FF FE 00 00 UTF-32-little-endian
+-- 4 00 00 FE FF UTF-32-big-endian
+
+unicode.utfname = {
+ [0] = 'utf-8',
+ [1] = 'utf-16-le',
+ [2] = 'utf-16-be',
+ [3] = 'utf-32-le',
+ [4] = 'utf-32-be'
+}
+
+function unicode.utftype(f) -- \000 fails !
+ local str = f:read(4)
+ if not str then
+ f:seek('set')
+ return 0
+ elseif find(str,"^%z%z\254\255") then
+ return 4
+ elseif find(str,"^\255\254%z%z") then
+ return 3
+ elseif find(str,"^\254\255") then
+ f:seek('set',2)
+ return 2
+ elseif find(str,"^\255\254") then
+ f:seek('set',2)
+ return 1
+ elseif find(str,"^\239\187\191") then
+ f:seek('set',3)
+ return 0
+ else
+ f:seek('set')
+ return 0
+ end
+end
+
+function unicode.utf16_to_utf8(str, endian) -- maybe a gsub is faster or an lpeg
+ local result, tmp, n, m, p = { }, { }, 0, 0, 0
+ -- lf | cr | crlf / (cr:13, lf:10)
+ local function doit()
+ if n == 10 then
+ if p ~= 13 then
+ result[#result+1] = concat(tmp)
+ tmp = { }
+ p = 0
+ end
+ elseif n == 13 then
+ result[#result+1] = concat(tmp)
+ tmp = { }
+ p = n
+ else
+ tmp[#tmp+1] = utfchar(n)
+ p = 0
+ end
+ end
+ for l,r in bytepairs(str) do
+ if r then
+ if endian then
+ n = l*256 + r
+ else
+ n = r*256 + l
+ end
+ if m > 0 then
+ n = (m-0xD800)*0x400 + (n-0xDC00) + 0x10000
+ m = 0
+ doit()
+ elseif n >= 0xD800 and n <= 0xDBFF then
+ m = n
+ else
+ doit()
+ end
+ end
+ end
+ if #tmp > 0 then
+ result[#result+1] = concat(tmp)
+ end
+ return result
+end
+
+function unicode.utf32_to_utf8(str, endian)
+ local result = { }
+ local tmp, n, m, p = { }, 0, -1, 0
+ -- lf | cr | crlf / (cr:13, lf:10)
+ local function doit()
+ if n == 10 then
+ if p ~= 13 then
+ result[#result+1] = concat(tmp)
+ tmp = { }
+ p = 0
+ end
+ elseif n == 13 then
+ result[#result+1] = concat(tmp)
+ tmp = { }
+ p = n
+ else
+ tmp[#tmp+1] = utfchar(n)
+ p = 0
+ end
+ end
+ for a,b in bytepairs(str) do
+ if a and b then
+ if m < 0 then
+ if endian then
+ m = a*256*256*256 + b*256*256
+ else
+ m = b*256 + a
+ end
+ else
+ if endian then
+ n = m + a*256 + b
+ else
+ n = m + b*256*256*256 + a*256*256
+ end
+ m = -1
+ doit()
+ end
+ else
+ break
+ end
+ end
+ if #tmp > 0 then
+ result[#result+1] = concat(tmp)
+ end
+ return result
+end
+
+local function little(c)
+ local b = byte(c) -- b = c:byte()
+ if b < 0x10000 then
+ return char(b%256,b/256)
+ else
+ b = b - 0x10000
+ local b1, b2 = b/1024 + 0xD800, b%1024 + 0xDC00
+ return char(b1%256,b1/256,b2%256,b2/256)
+ end
+end
+
+local function big(c)
+ local b = byte(c)
+ if b < 0x10000 then
+ return char(b/256,b%256)
+ else
+ b = b - 0x10000
+ local b1, b2 = b/1024 + 0xD800, b%1024 + 0xDC00
+ return char(b1/256,b1%256,b2/256,b2%256)
+ end
+end
+
+function unicode.utf8_to_utf16(str,littleendian)
+ if littleendian then
+ return char(255,254) .. utfgsub(str,".",little)
+ else
+ return char(254,255) .. utfgsub(str,".",big)
+ end
+end