Import ConTeX's lua libraries

Replace most of luaextra.lua with a bunch of require() calls and add
renamed (but unmodified) ConTeX lua libraries to the repository.

ConTeXt's l-xml.lua module has been excluded because it depends on a
bunch of other ConTeXt specific modules. Also l-pdfview.lua has been
dropped, I don't know what to use it for.

1 files changed, 193 insertions, 0 deletions

diff --git a/luaextra-unicode.lua b/luaextra-unicode.lua
new file mode 100644
index 0000000..290234d
--- /dev/null
+++ b/luaextra-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