--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/runtime/internal/util/ctype.d	Fri Aug 01 00:32:06 2008 +0200
@@ -0,0 +1,106 @@
+
+/*
+ *  Copyright (C) 2004-2005 by Digital Mars, www.digitalmars.com
+ *  Written by Walter Bright
+ *
+ *  This software is provided 'as-is', without any express or implied
+ *  warranty. In no event will the authors be held liable for any damages
+ *  arising from the use of this software.
+ *
+ *  Permission is granted to anyone to use this software for any purpose,
+ *  including commercial applications, and to alter it and redistribute it
+ *  freely, in both source and binary form, subject to the following
+ *  restrictions:
+ *
+ *  o  The origin of this software must not be misrepresented; you must not
+ *     claim that you wrote the original software. If you use this software
+ *     in a product, an acknowledgment in the product documentation would be
+ *     appreciated but is not required.
+ *  o  Altered source versions must be plainly marked as such, and must not
+ *     be misrepresented as being the original software.
+ *  o  This notice may not be removed or altered from any source
+ *     distribution.
+ */
+
+// Simple ASCII char classification functions
+
+module util.ctype;
+
+int isalnum(dchar c)  { return (c <= 0x7F) ? _ctype[c] & (_ALP|_DIG) : 0; }
+int isalpha(dchar c)  { return (c <= 0x7F) ? _ctype[c] & (_ALP)      : 0; }
+int iscntrl(dchar c)  { return (c <= 0x7F) ? _ctype[c] & (_CTL)      : 0; }
+int isdigit(dchar c)  { return (c <= 0x7F) ? _ctype[c] & (_DIG)      : 0; }
+int islower(dchar c)  { return (c <= 0x7F) ? _ctype[c] & (_LC)       : 0; }
+int ispunct(dchar c)  { return (c <= 0x7F) ? _ctype[c] & (_PNC)      : 0; }
+int isspace(dchar c)  { return (c <= 0x7F) ? _ctype[c] & (_SPC)      : 0; }
+int isupper(dchar c)  { return (c <= 0x7F) ? _ctype[c] & (_UC)       : 0; }
+int isxdigit(dchar c) { return (c <= 0x7F) ? _ctype[c] & (_HEX)      : 0; }
+int isgraph(dchar c)  { return (c <= 0x7F) ? _ctype[c] & (_ALP|_DIG|_PNC) : 0; }
+int isprint(dchar c)  { return (c <= 0x7F) ? _ctype[c] & (_ALP|_DIG|_PNC|_BLK) : 0; }
+int isascii(dchar c)  { return c <= 0x7F; }
+
+dchar tolower(dchar c)
+    out (result)
+    {
+	assert(!isupper(result));
+    }
+    body
+    {
+	return isupper(c) ? c + (cast(dchar)'a' - 'A') : c;
+    }
+
+dchar toupper(dchar c)
+    out (result)
+    {
+	assert(!islower(result));
+    }
+    body
+    {
+	return islower(c) ? c - (cast(dchar)'a' - 'A') : c;
+    }
+
+private:
+
+enum
+{
+    _SPC =	8,
+    _CTL =	0x20,
+    _BLK =	0x40,
+    _HEX =	0x80,
+    _UC  =	1,
+    _LC  =	2,
+    _PNC =	0x10,
+    _DIG =	4,
+    _ALP =	_UC|_LC,
+}
+
+ubyte _ctype[128] =
+[
+	_CTL,_CTL,_CTL,_CTL,_CTL,_CTL,_CTL,_CTL,
+	_CTL,_CTL|_SPC,_CTL|_SPC,_CTL|_SPC,_CTL|_SPC,_CTL|_SPC,_CTL,_CTL,
+	_CTL,_CTL,_CTL,_CTL,_CTL,_CTL,_CTL,_CTL,
+	_CTL,_CTL,_CTL,_CTL,_CTL,_CTL,_CTL,_CTL,
+	_SPC|_BLK,_PNC,_PNC,_PNC,_PNC,_PNC,_PNC,_PNC,
+	_PNC,_PNC,_PNC,_PNC,_PNC,_PNC,_PNC,_PNC,
+	_DIG|_HEX,_DIG|_HEX,_DIG|_HEX,_DIG|_HEX,_DIG|_HEX,
+	_DIG|_HEX,_DIG|_HEX,_DIG|_HEX,_DIG|_HEX,_DIG|_HEX,
+	_PNC,_PNC,_PNC,_PNC,_PNC,_PNC,
+	_PNC,_UC|_HEX,_UC|_HEX,_UC|_HEX,_UC|_HEX,_UC|_HEX,_UC|_HEX,_UC,
+	_UC,_UC,_UC,_UC,_UC,_UC,_UC,_UC,
+	_UC,_UC,_UC,_UC,_UC,_UC,_UC,_UC,
+	_UC,_UC,_UC,_PNC,_PNC,_PNC,_PNC,_PNC,
+	_PNC,_LC|_HEX,_LC|_HEX,_LC|_HEX,_LC|_HEX,_LC|_HEX,_LC|_HEX,_LC,
+	_LC,_LC,_LC,_LC,_LC,_LC,_LC,_LC,
+	_LC,_LC,_LC,_LC,_LC,_LC,_LC,_LC,
+	_LC,_LC,_LC,_PNC,_PNC,_PNC,_PNC,_CTL
+];
+
+
+unittest
+{
+    assert(isspace(' '));
+    assert(!isspace('z'));
+    assert(toupper('a') == 'A');
+    assert(tolower('Q') == 'q');
+    assert(!isxdigit('G'));
+}