digitalmars.D.learn - dchar, wchar, char conversions: what is the best practice?
- Kevin Bealer (81/81) Feb 03 2007 What is the 'best practice' when converting from dchar to char or vice
- =?ISO-8859-1?Q?Anders_F_Bj=F6rklund?= (4/11) Feb 03 2007 No Magic in Phobos, sorry...
- Kevin Bealer (3/18) Feb 03 2007 Thanks -- nice writeup btw.
- torhu (4/11) Feb 03 2007 import std.utf;
What is the 'best practice' when converting from dchar to char or vice versa? And wchar of course. I expected this code to do a magic conversion: dchar[] one = "one"; char[] one_a = cast(char[]) one; Instead, it produces 'o...n...e...' where . is a 0 byte, in other words it casts the D type of the array but does not change the encoding. I think this is not entirely unreasonable design, but, since implicit conversions don't work and explicit conversions do as shown above, there must be some standard way of going from one format to another, right? I have this: dchar[] okay; foreach(ch; c) { okay ~= ch; } Which seems to work fine, but seems a little piecemeal. Is there a more standard idiomatic way to do this? Kevin // Code import std.stdio; void hexdump(T)(char[] z, T[] s) { char[] pad = z.dup; pad[] = ' '; writefln("%s, %s * %s", z, s.length, T.sizeof); writef("%s --> ", z); byte * b = cast(byte*) s.ptr; int N = s.length*T.sizeof; for(int i = 0; i < N; i++) { writef("%2.2x ", b[i]); if ((i & 7) == 7) writef("\n %s ", pad); } writefln("\n"); } int main() { char[] c = "abcd"; wchar[] w = "1234"; dchar[] d = "WXYZ"; dchar[] okay; foreach(ch; c) { okay ~= ch; } char[] okay2; foreach(ch; okay) { okay2 ~= ch; } hexdump("char", c); hexdump("wchar", w); hexdump("dchar", d); hexdump("okay-C", okay); hexdump("okay-D", okay2); char[] dc = cast(char[]) d; char[] wc = cast(char[]) w; dchar[] cd = cast(dchar[]) c; hexdump!(char) ("d-to-c", dc); hexdump!(char) ("w-to-c", wc); hexdump!(dchar)("c-to-d", cd); return 0; } // Output char, 4 * 1 char --> 61 62 63 64 wchar, 4 * 2 wchar --> 31 00 32 00 33 00 34 00 dchar, 4 * 4 dchar --> 57 00 00 00 58 00 00 00 59 00 00 00 5a 00 00 00 okay-C, 4 * 4 okay-C --> 61 00 00 00 62 00 00 00 63 00 00 00 64 00 00 00 okay-D, 4 * 1 okay-D --> 61 62 63 64 d-to-c, 16 * 1 d-to-c --> 57 00 00 00 58 00 00 00 59 00 00 00 5a 00 00 00 w-to-c, 8 * 1 w-to-c --> 31 00 32 00 33 00 34 00 c-to-d, 1 * 4 c-to-d --> 61 62 63 64
Feb 03 2007
Kevin Bealer wrote:What is the 'best practice' when converting from dchar to char or vice versa? And wchar of course.http://www.prowiki.org/wiki4d/wiki.cgi?CharsAndStrsI expected this code to do a magic conversion: dchar[] one = "one"; char[] one_a = cast(char[]) one;No Magic in Phobos, sorry... --anders
Feb 03 2007
Anders F Björklund wrote:Kevin Bealer wrote:Thanks -- nice writeup btw. KevinWhat is the 'best practice' when converting from dchar to char or vice versa? And wchar of course.http://www.prowiki.org/wiki4d/wiki.cgi?CharsAndStrsI expected this code to do a magic conversion: dchar[] one = "one"; char[] one_a = cast(char[]) one;No Magic in Phobos, sorry... --anders
Feb 03 2007
Kevin Bealer wrote:What is the 'best practice' when converting from dchar to char or vice versa? And wchar of course. I expected this code to do a magic conversion: dchar[] one = "one"; char[] one_a = cast(char[]) one;import std.utf; char[] one_a = toUTF8(one); There's also toUTF16 and toUTF32.
Feb 03 2007