public override int decode(InStream @in)
{
int c = @in.r();
if (c < 0) return -1;
int c2, c3;
switch (c >> 4)
{
case 0: case 1: case 2: case 3: case 4: case 5: case 6: case 7:
/* 0xxxxxxx*/
return c;
case 12: case 13:
/* 110x xxxx 10xx xxxx*/
c2 = @in.r();
if ((c2 & 0xC0) != 0x80)
throw IOErr.make("Invalid UTF-8 encoding").val;
return ((c & 0x1F) << 6) | (c2 & 0x3F);
case 14:
/* 1110 xxxx 10xx xxxx 10xx xxxx */
c2 = @in.r();
c3 = @in.r();
if (((c2 & 0xC0) != 0x80) || ((c3 & 0xC0) != 0x80))
throw IOErr.make("Invalid UTF-8 encoding").val;
return (((c & 0x0F) << 12) | ((c2 & 0x3F) << 6) | ((c3 & 0x3F) << 0));
default:
throw IOErr.make("Invalid UTF-8 encoding").val;
}
}