On 6/24/17 3:53 AM, Meta wrote:
The code:
alias Response = Nullable!(string, "empty response (error)");
Response processMessage(string commandModule)(string message, bool
isCommand)
{
import std.meta;
import std.string;
import std.traits;
import command_uda;
mixin("import " ~ commandModule ~ ';');
bool foundCommandMatch = false;
foreach(symbol; getSymbolsByUDA!(mixin(commandModule), Command))
{
enum commandUDA = getUDAs!(symbol, Command)[0];
auto commandPhrase = commandUDA.phrase == "" ? symbol.stringof
: commandUDA.phrase; //Error: function <function signature> is not
callable using argument types ()
auto commandPhrasePattern = regex(`^%s\s`.format(commandPhrase));
if (message.matchFirst(commandPhrasePattern) &&
!foundCommandMatch)
{
version(responseDebug) writeln("Matched command ",
symbol.stringof, " with phrase '", commandPhrase, "'\n"); //Same issue
return Response(symbol(message.strip()));
}
}
return Response.init;
}
I've been banging my head against this and cannot figure out why
`symbol.stringof` is being called instead of getting a string of the
symbol. I tried to create a reduced test case but it works fine:
import std.stdio;
import std.traits;
enum Attr;
@Attr string test1() { return __FUNCTION__; }
@Attr string test2() { return __FUNCTION__; }
void process()
{
foreach (symbol; getSymbolsByUDA!(mixin(__MODULE__), Attr))
{
writeln("The result of calling ", symbol.stringof, " is ",
symbol());
}
}
void main()
{
process();
}
So I have no clue what I'm doing wrong. This is driving me insane.
I know what you are doing wrong in your reduced case. Try this instead:
@Attr string test1(int) { return __FUNCTION__; }
@Attr string test2(int) { return __FUNCTION__; }
void process()
{
foreach (symbol; getSymbolsByUDA!(mixin(__MODULE__), Attr))
{
writeln("The result of calling ", symbol.stringof, " is ",
symbol(1));
}
}
The reason your version "works" is because your functions actually are
callable with no args!
I tried many things including:
enum symbolname = symbol.stringof;
enum symbolname = (symbol).stringof;
pragma(msg, symbol.stringof);
Nothing works. If this isn't already a bug, you should file it. Aside
from ketmar's workaround, I can't think of one.
It's interesting that the ability to call without parentheses is what
causes the error, yet when you *can* call without parentheses, it
doesn't actually do so (symbol.stringof prints the name of the symbol).
This seems very obviously to be a bug.
-Steve
