n.c.

[chise/ruby.git] / chise / utf8.rb

diff --git a/chise/utf8.rb b/chise/utf8.rb
new file mode 100755 (executable)
index 0000000..eca2e80
--- /dev/null
+++ b/chise/utf8.rb
@@ -0,0 +1,88 @@
+# Copyright (C) 2002-2004 Kouichirou Eto, All rights reserved.
+
+module CHISE
+  module UTF8Value
+    def u8toi(str)
+      raise if str.nil?
+
+      i = 0
+      len = str.length
+
+      raise unless 1 <= len
+
+      c = str[i]
+      i += 1
+
+      if ( c < 0xC0 )
+       cid = c
+       counter = 0
+      elsif ( c < 0xE0 )
+       cid = c & 0x1f
+       counter = 1
+      elsif ( c < 0xF0 )
+       cid = c & 0x0f
+       counter = 2
+      elsif ( c < 0xF8 )
+       cid = c & 0x07
+       counter = 3
+      elsif ( c < 0xFC )
+       cid = c & 0x03
+       counter = 4
+      else
+       cid = c & 0x01
+       counter = 5
+      end
+
+      if (counter + 1 <= len)
+       (0...counter).each {|j|
+         cid = (cid << 6) | (str[j + i] & 0x3F)
+       }
+       return cid
+      end
+
+      raise
+    end
+
+    def itou8(cid)
+      raise unless cid.kind_of?(Integer)
+      if (cid <= 0x7F)
+       return ""+cid.chr
+      elsif (cid <= 0x7FF)
+       dest = "  "
+       dest[0] = (cid >> 6) | 0xC0
+       dest[1] = (cid & 0x3F) | 0x80
+       return dest
+      elsif (cid <= 0xFFFF)
+       dest = "   "
+       dest[0] =  (cid >> 12) | 0xE0
+       dest[1] = ((cid >>  6) & 0x3F) | 0x80
+       dest[2] =  (cid        & 0x3F) | 0x80
+       return dest
+      elsif (cid <= 0x1FFFFF)
+       dest = "    "
+       dest[0] =  (cid >> 18) | 0xF0
+       dest[1] = ((cid >> 12) & 0x3F) | 0x80
+       dest[2] = ((cid >>  6) & 0x3F) | 0x80
+       dest[3] =  (cid        & 0x3F) | 0x80
+       return dest
+      elsif (cid <= 0x3FFFFFF)
+       dest = "     "
+       dest[0] =  (cid >> 24) | 0xF8
+       dest[1] = ((cid >> 18) & 0x3F) | 0x80
+       dest[2] = ((cid >> 12) & 0x3F) | 0x80
+       dest[3] = ((cid >>  6) & 0x3F) | 0x80
+       dest[4] =  (cid        & 0x3F) | 0x80
+       return dest
+      else
+       dest = "      "
+       dest[0] =  (cid >> 30) | 0xFC
+       dest[1] = ((cid >> 24) & 0x3F) | 0x80
+       dest[2] = ((cid >> 18) & 0x3F) | 0x80
+       dest[3] = ((cid >> 12) & 0x3F) | 0x80
+       dest[4] = ((cid >>  6) & 0x3F) | 0x80
+       dest[5] =  (cid        & 0x3F) | 0x80
+       return dest
+      end
+    end
+  end
+end