Revert pre-alpha 3.0.0 because I was supposed to push it to a branch.

This reverts commit cbf25999f0.

halyde/lib/unicode.lua

@@ -0,0 +1,102 @@
+local unicodeLib
+local LLunicode
+if table.copy then
+  unicodeLib = table.copy(unicode)
+  LLunicode = table.copy(unicode)
+else
+  unicodeLib = {}
+  LLunicode = unicode
+end
+
+function unicodeLib.readCodePoint(readByte)
+  checkArg(1,readByte,"function")
+
+  local function inRange(min,max,...)
+    for _,v in ipairs({...}) do
+      if not (v and v>=min and v<max) then return false end
+    end
+    return true
+  end
+
+  local byte = readByte()
+  if byte==nil then return end
+
+  if byte < 0x80 then
+    -- ASCII character (0xxxxxxx)
+    return byte
+  elseif byte < 0xC0 then
+    -- Continuation byte (10xxxxxx), invalid at start position
+    return nil
+  elseif byte < 0xE0 then
+    -- 2-byte sequence (110xxxxx 10xxxxxx)
+    local byte2 = readByte()
+    if byte2==nil then return nil end
+    if inRange(0x80,0xC0,byte2) then
+      local code_point = ((byte & 0x1F) << 6) | (byte2 & 0x3F)
+      return code_point
+    end
+  elseif byte < 0xF0 then
+    -- 3-byte sequence (1110xxxx 10xxxxxx 10xxxxxx)
+    local byte2, byte3 = readByte(), readByte()
+    if byte2==nil and byte3==nil then return nil end
+    if inRange(0x80,0xC0,byte2,byte3)then
+      local code_point = ((byte & 0x0F) << 12) | ((byte2 & 0x3F) << 6) | (byte3 & 0x3F)
+      return code_point
+    end
+  elseif byte < 0xF8 then
+    -- 4-byte sequence (11110xxx 10xxxxxx 10xxxxxx 10xxxxxx)
+    local byte2, byte3, byte4 = readByte(), readByte(), readByte()
+    if byte2==nil and byte3==nil and byte4==nil then return nil end
+    if inRange(0x80,0xC0,byte2,byte3,byte4) then
+      local code_point = ((byte & 0x07) << 18) | ((byte2 & 0x3F) << 12) | ((byte3 & 0x3F) << 6) | (byte4 & 0x3F)
+      return code_point
+    end
+  end
+
+  -- Invalid UTF-8 byte sequence
+  return nil
+end
+
+function unicodeLib.readChar(readByte)
+  checkArg(1,readByte,"function")
+  return LLunicode.char(unicodeLib.readCodePoint(readByte))
+end
+
+function unicodeLib.codepoint(chr)
+  checkArg(1,chr,"string")
+  local ptr = 1
+  return unicode.readCodePoint(function()
+      local byte = chr:byte(ptr)
+      ptr=ptr+1
+      return byte
+  end),ptr-1
+end
+
+function unicodeLib.iterate(readByte)
+  checkArg(1,readByte,"string","function")
+  if type(readByte)=="string" then
+    local str,ptr = readByte,0
+    readByte = function()
+      ptr=ptr+1
+      return str:byte(ptr)
+    end
+  end
+  return function()
+    local point = unicodeLib.readCodePoint(readByte)
+    if point==nil then return nil end
+    return LLunicode.char(point),point
+  end
+end
+
+unicodeLib.char = LLunicode.char
+unicodeLib.charWidth = LLunicode.charWidth
+unicodeLib.isWide = LLunicode.isWide
+unicodeLib.len = LLunicode.len
+unicodeLib.lower = LLunicode.lower
+unicodeLib.reverse = LLunicode.reverse
+unicodeLib.sub = LLunicode.sub
+unicodeLib.upper = LLunicode.upper
+unicodeLib.wlen = LLunicode.wlen
+unicodeLib.wtrunc = LLunicode.wtrunc
+
+return unicodeLib