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April 21, 2004 D: nice, although still puzzling | ||||
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/* ** My first D-day; got three newbie questions: ** (1) Is there a way to avoid using malloc() in order to ** create instances of a structure? Something D-like? ** [Other than "Free Lists"] see: CreateMyList() below ** (2) Does the garbage collector manage memory that has ** been allocated with the c-lib funcs? -> ** Say, I pluck a node out of my list, never use it ** again during runtime, but won't free it explicitly. ** (3) Are there any new os-independent facilities that ** make file accesses more convenient in D? */ import std.c.stdlib; struct MyList { uint nFoo; MyList* psNext; } MyList* CreateMyList(uint nNodes) { MyList* psFirstNode = (MyList*)malloc(MyList.size); MyList* psTempNode = psFirstNode; printf("\n New Node at: 0x%X", psTempNode); psTempNode.nFoo = --nNodes; // I initially feared this coding style wouldn't be allowed. while(nNodes--) psTempNode = psTempNode.psNext = (MyList*)malloc(MyList.size), printf("\n New Node at: 0x%X", psTempNode), psTempNode.nFoo = nNodes; return (psFirstNode); } uint main() { // Great! This nonsense still works :) "D somehow", "well", "feels like C" && "that's nice"; MyList* psFirstNode = CreateMyList(0xFF); do printf("\n Val: %u", psFirstNode.nFoo); while(psFirstNode.nFoo != 0, psFirstNode = psFirstNode.psNext); // Well, but where's that gone... // psFirstNode.psNext = ((void*)0); return (0x0); } |
April 21, 2004 Re: D: nice, although still puzzling | ||||
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Posted in reply to Chr. Grade | Chr. Grade wrote:
> ** (1) Is there a way to avoid using malloc() in order to
> ** create instances of a structure? Something D-like?
> ** [Other than "Free Lists"] see: CreateMyList() below
I've yet to ever even use malloc() from D.
As to your provided program... consider the following (untested) re-write:
------------------------------
struct MyList {
uint foo;
MyList* next;
static MyList* create(uint nodes) {
MyList first;
MyList* tmp = &first;
void report() {
printf("\n New Node at: 0x%X", tmp);
}
report();
tmp.foo = --nodes;
while (nodes--) {
tmp.next = new MyList;
tmp = tmp.next;
report();
tmp.foo = nodes;
}
return &first;
}
}
int main() {
MyList* node = MyList.create(0xFF);
while (node) {
printf("\n Val: %u", node.foo);
node = node.next;
}
return 0;
}
------------------------------
-C. Sauls
-Invironz
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April 21, 2004 Re: nice, although still puzzling | ||||
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Posted in reply to Chr. Grade | "Chr. Grade" <Chr._member@pathlink.com> wrote in message news:c66du7$1nd8$1@digitaldaemon.com... > > /* > ** My first D-day; got three newbie questions: > ** (1) Is there a way to avoid using malloc() in order to > ** create instances of a structure? Something D-like? > ** [Other than "Free Lists"] see: CreateMyList() below Yes. new MyList; > ** (2) Does the garbage collector manage memory that has > ** been allocated with the c-lib funcs? -> No. If a program goes outside of the gc, then the programmer is totally in charge of that <g>. > ** Say, I pluck a node out of my list, never use it > ** again during runtime, but won't free it explicitly. If it was allocated with malloc(), it must be explicitly free()'d. > ** (3) Are there any new os-independent facilities that > ** make file accesses more convenient in D? std.file offers a few. |
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