digitalmars.D - Can I load an Dynamic Real Array on one line?
- David L. Davis (25/25) Jul 17 2004 Could someone please point out what I'm doing incorrectly in trying to a...
- Andy Friesen (19/44) Jul 17 2004 Maybe this needs to be added to Phobos. ;)
- Matthew (5/48) Jul 17 2004 a
- Regan Heath (9/66) Jul 17 2004 It should be mentioned that the original poster required an 'array
- David L. Davis (84/84) Jul 17 2004 Andy Friesen: Thanks for the reply and the template. Well, I hate to bug...
- Andy Friesen (10/21) Jul 17 2004 There's a few things going on here. The big one is that the assert is
- David L. Davis (71/71) Jul 19 2004 Andy Friesen: I've only been able to get the template to work so far wit...
- Derek (7/32) Jul 17 2004 I think its because D has not (yet?) implemented array literals. Thus an...
- Ilya Minkov (19/47) Jul 22 2004 This is a well known "feature" in the compiler, though i believe leaving...
- Regan Heath (21/66) Jul 22 2004 No it's not :)
- David L. Davis (3/3) Jul 22 2004 Ilya Minkov and Regan Heath: Thxs for your replys on this subject! :)
- Ilya Minkov (5/15) Jul 23 2004 whoops! i would never write that myself, it's here because i first
- Regan Heath (9/24) Jul 23 2004 It has _never_ 'worked' for me, as in, given me a compile time or runtim...
Could someone please point out what I'm doing incorrectly in trying to assign a series of real values on one line into a dynamic real array? Thxs for any help in advance! :) ------------------------------------------------------------------- "Dare to reach for the Stars...Dare to Dream, Build, and Achieve!"
Jul 17 2004
David L. Davis wrote:Could someone please point out what I'm doing incorrectly in trying to assign a series of real values on one line into a dynamic real array? Thxs for any help in advance! :)Maybe this needs to be added to Phobos. ;) import std.stdarg; template makeArray(T) { T[] makeArray(...) { T[] result; result.length = _arguments.length; for (int index, TypeInfo ti; _arguments) { // FIXME: handle derived class types and interfaces correctly. assert(ti === typeid(T)); result[index] = va_arg!(T)(_argptr); } } } Then you can just do: real[] realArray = makeArray!(real)(-70_000, 12_000, 15_000, 18_000, 21_000); -- andy
Jul 17 2004
"Andy Friesen" <andy ikagames.com> wrote in message news:cdbvuh$1im0$1 digitaldaemon.com...David L. Davis wrote:aCould someone please point out what I'm doing incorrectly in trying to assignIf it's not added to Phobos, can we put this in dtl.utility.arrays; ? Please remind me of this once DTL 0.1 is out there.series of real values on one line into a dynamic real array? Thxs for any help in advance! :)Maybe this needs to be added to Phobos. ;) import std.stdarg; template makeArray(T) { T[] makeArray(...) { T[] result; result.length = _arguments.length; for (int index, TypeInfo ti; _arguments) { // FIXME: handle derived class types and interfaces correctly. assert(ti === typeid(T)); result[index] = va_arg!(T)(_argptr); } } } Then you can just do: real[] realArray = makeArray!(real)(-70_000, 12_000, 15_000, 18_000, 21_000);
Jul 17 2004
Regan Heath <regan netwin.co.nz> On Sun, 18 Jul 2004 06:40:07 +1000, Matthew <admin stlsoft.dot.dot.dot.dot.org> wrote:"Andy Friesen" <andy ikagames.com> wrote in message news:cdbvuh$1im0$1 digitaldaemon.com...It should be mentioned that the original poster required an 'array literal' which Walter has hinted will be possible eventually. I believe the stumbling blocks include not being able to find a 'nice' syntax (which is also unambiguous). Regan -- Using M2, Opera's revolutionary e-mail client: http://www.opera.com/m2/David L. Davis wrote:aCould someone please point out what I'm doing incorrectly in tryingto assignIf it's not added to Phobos, can we put this in dtl.utility.arrays; ? Please remind me of this once DTL 0.1 is out there.series of real values on one line into a dynamic real array?array'statement'"Thxs for any help in advance! :)Maybe this needs to be added to Phobos. ;) import std.stdarg; template makeArray(T) { T[] makeArray(...) { T[] result; result.length = _arguments.length; for (int index, TypeInfo ti; _arguments) { // FIXME: handle derived class types and interfaces correctly. assert(ti === typeid(T)); result[index] = va_arg!(T)(_argptr); } } } Then you can just do: real[] realArray = makeArray!(real)(-70_000, 12_000, 15_000, 18_000, 21_000);
Jul 17 2004
Andy Friesen: Thanks for the reply and the template. Well, I hate to bug you, but I can't seem to get it to work correctly, could please take another looks at it? First problem I ran into soon after I fixed the "for" to a "foreach", was that it appears that writefln() and the template both define va_arg() differently, so I get an error trying to use both...thus I moved to using printf() which surprising works under std.stdio instead forcing std.c.stdio to be imported. Secondly I had a problem with the assert( ti === typeid( T ) ) statement firing off, meaning ti and typeid( T ) aren't equal to one another. And then the Third problem poped up after I commented out the assert() statement, in which of the four real numbers -200.0, 500.0, 324.0, -230.0 passed into the template, only -200. and -230.0 showed up in the final array (as shown below). Please note that -230.0 was suppose to be the last value in the array. C:\dmd>dynarray _arguments.length=4 typeid( real )=4257752, ti=4256136, result[ 0 ]= -200.0000 typeid( real )=4257752, ti=4256136, result[ 1 ]= 0.0000 typeid( real )=4257752, ti=4256136, result[ 2 ]= -230.0000 typeid( real )=4257752, ti=4256136, result[ 3 ]= 0.0000 I would really like to get this to work if all possible. Plus it just seems like such a very "D" way of doing things "rArr[] = [ list of values, ... ];", but that's me. Thanks for your help. _D3std6stdarg8va_arg_e6va_argFKPvZe ------------------------------------------------------------------- "Dare to reach for the Stars...Dare to Dream, Build, and Achieve!"
Jul 17 2004
David L. Davis wrote:Andy Friesen: Thanks for the reply and the template. Well, I hate to bug you, but I can't seem to get it to work correctly, could please take another looks at it? Secondly I had a problem with the assert( ti === typeid( T ) ) statement firing off, meaning ti and typeid( T ) aren't equal to one another. And then the Third problem poped up after I commented out the assert() statement, in which of the four real numbers -200.0, 500.0, 324.0, -230.0 passed into the template, only -200. and -230.0 showed up in the final array (as shown below). Please note that -230.0 was suppose to be the last value in the array.There's a few things going on here. The big one is that the assert is there for a reason. ;) If it trips, then the types don't match. Suffixing the arguments with an L makes them reals, which causes the assertion to pass, and the return value to look like it ought to. eg. rArr = makeArray!(real)(-200.0L, 500.0L, 324.0L, -230.0L); The link conflict bug is mystifying. I can only assume it's a bug in the compiler. -- andy
Jul 17 2004
Andy Friesen: I've only been able to get the template to work so far with only char[]s as long as I add a NULL to the string, but even this is pretty useful! (Thought I'd post what I found thus far.) Thanks again for your replys. ---- Console Output ------------------- C:\dmd>dynarray sArr[] = makeArray!(char[])( "-200.0\0", "1200.0\0", "25.56\0" ); makeArray.result.length=3 makeArray.result[ 0 ] = -200.0 makeArray.result[ 1 ] = 1200.0 makeArray.result[ 2 ] = 25.56 returning... main.sArr.length=3 main.sArr[ 0 ] = -200.0 main.sArr[ 1 ] = 1200.0 main.sArr[ 2 ] = 25.56 C:\dmd> ---------------------------------------- ); \"25.56\\0\" );\n\n" ); ------------------------------------------------------------------- "Dare to reach for the Stars...Dare to Dream, Build, and Achieve!"
Jul 19 2004
On Sat, 17 Jul 2004 19:33:05 +0000 (UTC), David L. Davis wrote:Could someone please point out what I'm doing incorrectly in trying to assign a series of real values on one line into a dynamic real array? Thxs for any help in advance! :)I think its because D has not (yet?) implemented array literals. Thus any array initializations like this example, need to be done at run time rather than compile time. -- Derek Melbourne, Australia
Jul 17 2004
This is a well known "feature" in the compiler, though i believe leaving
this undocumented suxx. I do this (although it's one line too many):
int main() {
// Lay out the data
const real [] arr_prototype = [ -200.0, 500.0, 324.0, -230.0 ];
// Duplicate into a dynamic array
real arr[] = arr_prototype.dup;
// Make sure that assignment has taken place, just for demostration
assert (arr.length==4);
return 0;
}
Naturally, you can leave out the .dup and do a simple assignment, but
then you may not write anything into arr because it would be aliased
with arr_prototype, which is stored in a constant area.
Another thing you could make differently is have arr_prototype be a
static instead of const, but then you could occasionaly modify a global
variable, and that may not be what you want.
-eye
David L. Davis schrieb:
Could someone please point out what I'm doing incorrectly in trying to assign a
series of real values on one line into a dynamic real array?
Thxs for any help in advance! :)
-------------------------------------------------------------------
"Dare to reach for the Stars...Dare to Dream, Build, and Achieve!"
Jul 22 2004
On Thu, 22 Jul 2004 16:19:48 +0200, Ilya Minkov <minkov cs.tum.edu> wrote:This is a well known "feature" in the compiler, though i believe leaving this undocumented suxx. I do this (although it's one line too many): int main() { // Lay out the data const real [] arr_prototype = [ -200.0, 500.0, 324.0, -230.0 ]; // Duplicate into a dynamic array real arr[] = arr_prototype.dup; // Make sure that assignment has taken place, just for demostration assert (arr.length==4); return 0; } Naturally, you can leave out the .dup and do a simple assignment, but then you may not write anything into arr because it would be aliased with arr_prototype, which is stored in a constant area.No it's not :) This is the problem I have with 'const' currently, in your example the array _reference_ arr_prototype is const, but the data it contains/references is not. example: int main() { // Lay out the data const real[] arr_prototype = [ -200.0, 500.0, 324.0, -230.0 ]; // Duplicate into a dynamic array //real arr[] = arr_prototype.dup; //you used C style declaration? real[] arr = arr_prototype; // Make sure that assignment has taken place, just for demostration assert (arr.length == 4); arr[0] = 12; assert (arr[0] == arr_prototype[0]); return 0; } ReganAnother thing you could make differently is have arr_prototype be a static instead of const, but then you could occasionaly modify a global variable, and that may not be what you want. -eye David L. Davis schrieb:-- Using M2, Opera's revolutionary e-mail client: http://www.opera.com/m2/Could someone please point out what I'm doing incorrectly in trying to assign a Thxs for any help in advance! :) ------------------------------------------------------------------- "Dare to reach for the Stars...Dare to Dream, Build, and Achieve!"
Jul 22 2004
Ilya Minkov and Regan Heath: Thxs for your replys on this subject! :) ------------------------------------------------------------------- "Dare to reach for the Stars...Dare to Dream, Build, and Achieve!"
Jul 22 2004
Regan Heath schrieb:OK, even if it's not it's illegal. it just doesn't always work as intended.Naturally, you can leave out the .dup and do a simple assignment, but then you may not write anything into arr because it would be aliased with arr_prototype, which is stored in a constant area.No it's not :)This is the problem I have with 'const' currently, in your example the array _reference_ arr_prototype is const, but the data it contains/references is not.//real arr[] = arr_prototype.dup; //you used C style declaration? real[] arr = arr_prototype;whoops! i would never write that myself, it's here because i first copied David's code verbatim. :) -eye
Jul 23 2004
On Fri, 23 Jul 2004 14:10:53 +0200, Ilya Minkov <minkov cs.tum.edu> wrote:Regan Heath schrieb:It has _never_ 'worked' for me, as in, given me a compile time or runtime error saying I cannot modify that const data. I think it's been implemented as I desribed in that "const int[]" means a constant reference to an array of non constant data.OK, even if it's not it's illegal. it just doesn't always work as intended.Naturally, you can leave out the .dup and do a simple assignment, but then you may not write anything into arr because it would be aliased with arr_prototype, which is stored in a constant area.No it's not :)Just checking. :) Regan -- Using M2, Opera's revolutionary e-mail client: http://www.opera.com/m2/This is the problem I have with 'const' currently, in your example the array _reference_ arr_prototype is const, but the data it contains/references is not.//real arr[] = arr_prototype.dup; //you used C style declaration? real[] arr = arr_prototype;whoops! i would never write that myself, it's here because i first copied David's code verbatim. :)
Jul 23 2004