Re: Templates in classes => what is wrong?
On Tuesday, 17 April 2012 at 18:39:16 UTC, Xan wrote:
On Tuesday, 17 April 2012 at 18:25:21 UTC, Ali Çehreli wrote:
On 04/17/2012 11:13 AM, Xan wrote:
> The idea is behind this https://gist.github.com/2407923
> But I receive:
>
> $ gdmd-4.6 algorisme_code.d
> algorisme_code.d:22: Error: variable codi cannot be read at
compile time
> algorisme_code.d:22: Error: argument to mixin must be a
string, not (codi)
mixin is about code generation. For that reason the string
that is given to it must be available at compile time. Upon
analyzing the code, that is the case in your example, but
because mixin() appears inside the constructor, it cannot use
a string parameter.
That's why I had used a template parameter for the function
string. There may be a number of solutions but only you can
decide on what to do. One solution is to mixin the delegate
outside of the constructor and pass as an argument along with
its string representation:
// Untested code
this(... Funcio funcio, string funcioText) {
...
}
In main:
enum funcioText = "...";
auto funcio = mixin(funcioText);
... new Algorisme(..., funcio, funcioText);
Ali
What is change is this code? Is it the same as this
https://gist.github.com/2407923 (I revise the code)?
With my (v. 2) code I receive the errors:
$ gdmd-4.6 algorisme_code.d
algorisme_code.d:44: Error: variable codi cannot be read at
compile time
algorisme_code.d:44: Error: argument to mixin must be a string,
not (codi)
algorisme_code.d:45: Error: constructor
algorisme_code.Algorisme!(int,int).Algorisme.this (string nom,
uint versio, int function(int) funcio, string codi) is not
callable using argument types (string,int,_error_,string)
Why the string is not given at compile code? I don't understand
it!
Xan.
It works with enum instead of string:
https://gist.github.com/2407923
Thanks all of you,
Xan.
Re: Templates in classes => what is wrong?
On Tuesday, 17 April 2012 at 18:25:21 UTC, Ali Çehreli wrote:
On 04/17/2012 11:13 AM, Xan wrote:
> The idea is behind this https://gist.github.com/2407923
> But I receive:
>
> $ gdmd-4.6 algorisme_code.d
> algorisme_code.d:22: Error: variable codi cannot be read at
compile time
> algorisme_code.d:22: Error: argument to mixin must be a
string, not (codi)
mixin is about code generation. For that reason the string that
is given to it must be available at compile time. Upon
analyzing the code, that is the case in your example, but
because mixin() appears inside the constructor, it cannot use a
string parameter.
That's why I had used a template parameter for the function
string. There may be a number of solutions but only you can
decide on what to do. One solution is to mixin the delegate
outside of the constructor and pass as an argument along with
its string representation:
// Untested code
this(... Funcio funcio, string funcioText) {
...
}
In main:
enum funcioText = "...";
auto funcio = mixin(funcioText);
... new Algorisme(..., funcio, funcioText);
Ali
What is change is this code? Is it the same as this
https://gist.github.com/2407923 (I revise the code)?
With my (v. 2) code I receive the errors:
$ gdmd-4.6 algorisme_code.d
algorisme_code.d:44: Error: variable codi cannot be read at
compile time
algorisme_code.d:44: Error: argument to mixin must be a string,
not (codi)
algorisme_code.d:45: Error: constructor
algorisme_code.Algorisme!(int,int).Algorisme.this (string nom,
uint versio, int function(int) funcio, string codi) is not
callable using argument types (string,int,_error_,string)
Why the string is not given at compile code? I don't understand
it!
Xan.
Re: Templates in classes => what is wrong?
On 04/17/2012 11:13 AM, Xan wrote:
> The idea is behind this https://gist.github.com/2407923
> But I receive:
>
> $ gdmd-4.6 algorisme_code.d
> algorisme_code.d:22: Error: variable codi cannot be read at compile time
> algorisme_code.d:22: Error: argument to mixin must be a string, not
(codi)
mixin is about code generation. For that reason the string that is given
to it must be available at compile time. Upon analyzing the code, that
is the case in your example, but because mixin() appears inside the
constructor, it cannot use a string parameter.
That's why I had used a template parameter for the function string.
There may be a number of solutions but only you can decide on what to
do. One solution is to mixin the delegate outside of the constructor and
pass as an argument along with its string representation:
// Untested code
this(... Funcio funcio, string funcioText) {
...
}
In main:
enum funcioText = "...";
auto funcio = mixin(funcioText);
... new Algorisme(..., funcio, funcioText);
Ali
Re: Templates in classes => what is wrong?
On Tuesday, 17 April 2012 at 18:00:55 UTC, Xan wrote:
On Tuesday, 17 April 2012 at 15:59:25 UTC, Ali Çehreli wrote:
On 04/17/2012 08:42 AM, Xan wrote:
> How to get the "code" of a function or delegate
>
> |___string toString() {
> |___|___return format("%s (versió %s): Domini -> Recorregut,
%s(x) =
> %s", nom, versio, nom, &funcio);
>
> |___}
>
> does not produce the desired result and &funcio without
ampersand
> produces me an error.
>
> So, my doubts are:
> given a function:
>
> - how can I get the domain
> - how can I get the range
I did not understand those. :(
Domain is the set of values that we pass to the function and
Range is the set of Values which are returned by function.
V delegate (U) f;
f has Domain U and Range V
I want to "print" the type of "U" and "V".
Something like:
class Algorisme(U,V) {
string nom;
uint versio;
alias V delegate (U) Funcio;
Funcio funcio;
this(string nom, uint versio, Funcio funcio) {
this.nom = nom;
this.versio = versio;
this.funcio = funcio;
}
string toString() {
return format("%s (versió %s): %s -> %s, %s(x) = %s", nom,
versio, V, U, nom, &funcio);
}
}
but I receive
algorisme.d:24: Error: type int has no value
algorisme.d:24: Error: type int has no value
when I call with Algorisme!(int, int) intead of receiving "int"
and "int" as Domain and Range
> - how can I get the code of the function?
>
> See https://gist.github.com/2394274
>
I don't think D has any help there. You can keep the function
as a string yourself and convert to actual code at compile
time with a string mixin. For that to happen, the function
text may be an additional template parameter:
import std.conv, std.stdio, std.stream, std.string;
import std.socket, std.socketstream;
import std.datetime;
class Algorisme(U,V,string funcioText) {
string nom;
uint versio;
alias V delegate (U) Funcio;
Funcio funcio;
this(string nom, uint versio) {
this.nom = nom;
this.versio = versio;
this.funcio = mixin(funcioText);
}
string toString() {
return format("%s (versió %s): Domini ->
Recorregut, %s(x) = %s",
nom, versio, nom, funcioText);
}
}
alias Algorisme!(int, int, "(int a) { return 2 * a; }")
AlgorismeEnters;
void main(string [] args)
{
auto alg = new AlgorismeEnters("Doblar", 1);
writeln(alg);
}
Ali
It's ugly code. I think I could call some procedure like f.code
(f is a function) to obtain the "code" how f is defined. But
stricly in mathematical thinking it's not adequate, because
more codes could result in the same (mathematical function): x
+ x is the double of x; and 2*x is too.
Perhaps if I change Algorisme and add the string field "code"
and if there is any procedure to copy the 3rd argument in the
constructor and pass as string in the 4th argument (in the
constructor)
class Algorisme(U,V) {
|___string nom;
|___uint versio;
|___alias V delegate (U) Funcio;
|___Funcio funcio;
|___string code;
|___this(string nom, uint versio, Funcio funcio) {
|___|___this.nom = nom;
|___|___this.versio = versio;
|___|___this.funcio = funcio;
this.code = funcio.WHAT PROCEDURE?;
|___}
Regards,
Xan.
The idea is behind this https://gist.github.com/2407923
But I receive:
$ gdmd-4.6 algorisme_code.d
algorisme_code.d:22: Error: variable codi cannot be read at
compile time
algorisme_code.d:22: Error: argument to mixin must be a string,
not (codi)
What can I do?
Thanks,
Xan.
Re: Templates in classes => what is wrong?
On Tuesday, 17 April 2012 at 18:00:55 UTC, Xan wrote:
On Tuesday, 17 April 2012 at 15:59:25 UTC, Ali Çehreli wrote:
On 04/17/2012 08:42 AM, Xan wrote:
> How to get the "code" of a function or delegate
>
> |___string toString() {
> |___|___return format("%s (versió %s): Domini -> Recorregut,
%s(x) =
> %s", nom, versio, nom, &funcio);
>
> |___}
>
> does not produce the desired result and &funcio without
ampersand
> produces me an error.
>
> So, my doubts are:
> given a function:
>
> - how can I get the domain
> - how can I get the range
I did not understand those. :(
Domain is the set of values that we pass to the function and
Range is the set of Values which are returned by function.
V delegate (U) f;
f has Domain U and Range V
I want to "print" the type of "U" and "V".
Something like:
class Algorisme(U,V) {
string nom;
uint versio;
alias V delegate (U) Funcio;
Funcio funcio;
this(string nom, uint versio, Funcio funcio) {
this.nom = nom;
this.versio = versio;
this.funcio = funcio;
}
string toString() {
return format("%s (versió %s): %s -> %s, %s(x) = %s", nom,
versio, V, U, nom, &funcio);
}
}
but I receive
algorisme.d:24: Error: type int has no value
algorisme.d:24: Error: type int has no value
Solved with typeid:
string toString() {
|___|___return format("%s (versió %s): %s -> %s, %s(x) = %s",
nom, versio, typeid(V), typeid(U), nom, &funcio);
|___}
Re: Templates in classes => what is wrong?
On Tuesday, 17 April 2012 at 15:59:25 UTC, Ali Çehreli wrote:
On 04/17/2012 08:42 AM, Xan wrote:
> How to get the "code" of a function or delegate
>
> |___string toString() {
> |___|___return format("%s (versió %s): Domini -> Recorregut,
%s(x) =
> %s", nom, versio, nom, &funcio);
>
> |___}
>
> does not produce the desired result and &funcio without
ampersand
> produces me an error.
>
> So, my doubts are:
> given a function:
>
> - how can I get the domain
> - how can I get the range
I did not understand those. :(
Domain is the set of values that we pass to the function and
Range is the set of Values which are returned by function.
V delegate (U) f;
f has Domain U and Range V
I want to "print" the type of "U" and "V".
Something like:
class Algorisme(U,V) {
string nom;
uint versio;
alias V delegate (U) Funcio;
Funcio funcio;
this(string nom, uint versio, Funcio funcio) {
this.nom = nom;
this.versio = versio;
this.funcio = funcio;
}
string toString() {
return format("%s (versió %s): %s -> %s, %s(x) = %s", nom,
versio, V, U, nom, &funcio);
}
}
but I receive
algorisme.d:24: Error: type int has no value
algorisme.d:24: Error: type int has no value
when I call with Algorisme!(int, int) intead of receiving "int"
and "int" as Domain and Range
> - how can I get the code of the function?
>
> See https://gist.github.com/2394274
>
I don't think D has any help there. You can keep the function
as a string yourself and convert to actual code at compile time
with a string mixin. For that to happen, the function text may
be an additional template parameter:
import std.conv, std.stdio, std.stream, std.string;
import std.socket, std.socketstream;
import std.datetime;
class Algorisme(U,V,string funcioText) {
string nom;
uint versio;
alias V delegate (U) Funcio;
Funcio funcio;
this(string nom, uint versio) {
this.nom = nom;
this.versio = versio;
this.funcio = mixin(funcioText);
}
string toString() {
return format("%s (versió %s): Domini ->
Recorregut, %s(x) = %s",
nom, versio, nom, funcioText);
}
}
alias Algorisme!(int, int, "(int a) { return 2 * a; }")
AlgorismeEnters;
void main(string [] args)
{
auto alg = new AlgorismeEnters("Doblar", 1);
writeln(alg);
}
Ali
It's ugly code. I think I could call some procedure like f.code
(f is a function) to obtain the "code" how f is defined. But
stricly in mathematical thinking it's not adequate, because more
codes could result in the same (mathematical function): x + x is
the double of x; and 2*x is too.
Perhaps if I change Algorisme and add the string field "code" and
if there is any procedure to copy the 3rd argument in the
constructor and pass as string in the 4th argument (in the
constructor)
class Algorisme(U,V) {
|___string nom;
|___uint versio;
|___alias V delegate (U) Funcio;
|___Funcio funcio;
|___string code;
|___this(string nom, uint versio, Funcio funcio) {
|___|___this.nom = nom;
|___|___this.versio = versio;
|___|___this.funcio = funcio;
this.code = funcio.WHAT PROCEDURE?;
|___}
Regards,
Xan.
Re: Templates in classes => what is wrong?
On 04/17/2012 08:42 AM, Xan wrote:
> How to get the "code" of a function or delegate
>
> |___string toString() {
> |___|___return format("%s (versió %s): Domini -> Recorregut, %s(x) =
> %s", nom, versio, nom, &funcio);
>
> |___}
>
> does not produce the desired result and &funcio without ampersand
> produces me an error.
>
> So, my doubts are:
> given a function:
>
> - how can I get the domain
> - how can I get the range
I did not understand those. :(
> - how can I get the code of the function?
>
> See https://gist.github.com/2394274
>
I don't think D has any help there. You can keep the function as a
string yourself and convert to actual code at compile time with a string
mixin. For that to happen, the function text may be an additional
template parameter:
import std.conv, std.stdio, std.stream, std.string;
import std.socket, std.socketstream;
import std.datetime;
class Algorisme(U,V,string funcioText) {
string nom;
uint versio;
alias V delegate (U) Funcio;
Funcio funcio;
this(string nom, uint versio) {
this.nom = nom;
this.versio = versio;
this.funcio = mixin(funcioText);
}
string toString() {
return format("%s (versió %s): Domini -> Recorregut, %s(x)
= %s",
nom, versio, nom, funcioText);
}
}
alias Algorisme!(int, int, "(int a) { return 2 * a; }") AlgorismeEnters;
void main(string [] args)
{
auto alg = new AlgorismeEnters("Doblar", 1);
writeln(alg);
}
Ali
Re: Templates in classes => what is wrong?
On Tuesday, 17 April 2012 at 15:30:36 UTC, Ali Çehreli wrote:
On 04/17/2012 08:17 AM, Xan wrote:
Off-topic, could can I define toString having this structure:
(versió ): ->
,
?
(For example, in https://gist.github.com/2394274 I want that
Doblar
displays as:
Doblar (versió 1): int -> int, { return 2 * a; }
Thanks a lot,
Xan.
std.string.format is easy:
format("%s%s", 42, "hello");
Ali
How to get the "code" of a function or delegate
|___string toString() {
|___|___return format("%s (versió %s): Domini -> Recorregut,
%s(x) = %s", nom, versio, nom, &funcio);
|___}
does not produce the desired result and &funcio without ampersand
produces me an error.
So, my doubts are:
given a function:
- how can I get the domain
- how can I get the range
- how can I get the code of the function?
See https://gist.github.com/2394274
Re: Templates in classes => what is wrong?
On 04/17/2012 08:17 AM, Xan wrote:
Off-topic, could can I define toString having this structure:
(versió ): -> ,
?
(For example, in https://gist.github.com/2394274 I want that Doblar
displays as:
Doblar (versió 1): int -> int, { return 2 * a; }
Thanks a lot,
Xan.
std.string.format is easy:
format("%s%s", 42, "hello");
Ali
Re: Templates in classes => what is wrong?
On Tuesday, 17 April 2012 at 15:21:30 UTC, Dejan Lekic wrote:
On Tuesday, 17 April 2012 at 14:57:18 UTC, Xan wrote:
On Tuesday, 17 April 2012 at 01:31:43 UTC, Kenji Hara wrote:
On Monday, 16 April 2012 at 18:48:52 UTC, Xan wrote:
On Sunday, 15 April 2012 at 19:30:27 UTC, Ali Çehreli wrote:
On 04/15/2012 11:39 AM, Xan wrote:
> On Sunday, 15 April 2012 at 11:23:37 UTC, John Chapman
> wrote:
>> On Sunday, 15 April 2012 at 11:16:43 UTC, Xan wrote:
>>>
>>> int main(string [] args)
>>> {
>>> auto alg = Algorisme!(int,int);
>>
>> Should be:
>> auto alg = new Algorisme!(int, int);
>>
>>> alg.nom = "Doblar";
>>> alg.versio = 1;
>>> alg.funcio = (int a) {return 2*a};
>>
>> Should be:
>> alg.funcio = (int a) { return 2 * a; };
>> or:
>> alg.funcio = a => 2 * a;
>>
>>> }
>
>
> It does not work:
>
> $ gdmd-4.6 algorisme.d
> algorisme.d:18: Error: variable algorisme.main.alg voids
> have
no value
> algorisme.d:18: Error: expression class Algorisme is void
> and
has no value
>
> with the code https://gist.github.com/2394274
>
> What fails now?
>
> Thanks,
> Xan.
Your code is still missing 'new':
auto alg = new Algorisme!(int, int);
With only this change, I receive this error:
$ gdmd-4.6 algorisme.d
algorisme.d:21: Error: cannot implicitly convert expression
(__dgliteral1) of type int delegate(int a) pure nothrow to
int function(int)
Unrelated recommendations:
- Return 0 from main() for successful exit, anything else
by convention means some sort of error.
- Take advantage of constructors (and 'alias') to simplify
syntax and risk of bugs:
import std.conv, std.stdio, std.stream, std.string;
import std.socket, std.socketstream;
import std.datetime;
class Algorisme(U,V) {
string nom;
uint versio;
alias V function (U) Funcio;
Funcio funcio;
this(string nom, uint versio, Funcio funcio)
{
this.nom = nom;
this.versio = versio;
this.funcio = funcio;
}
}
int main(string [] args)
{
alias Algorisme!(int, int) MeuAlgorism;
auto alg = new MeuAlgorism("Doblar", 1,
(int a) { return 2 * a; });
return 0;
}
Ali
With all of your suggestion
[https://gist.github.com/2394274], I get:
$ gdmd-4.6 algorisme.d
algorisme.d:30: Error: constructor
algorisme.Algorisme!(int,int).Algorisme.this (string nom,
uint versio, int function(int) funcio) is not callable using
argument types (string,int,int delegate(int a) pure nothrow)
algorisme.d:30: Error: cannot implicitly convert expression
(__dgliteral1) of type int delegate(int a) pure nothrow to
int function(int)
algorisme.d:27: Error: function D main has no return
statement, but is expected to return a value of type int
What fails?
PS: Thanks for your recommendations...
PPS: By the other hand, I see you have learned catalan
("MeuAlgorisme"?) ;-)
Problem may be here:
alg.funcio = (int a) { return 2 * a; };
2.057 and earlier (You may use gdc 2.057 and command line
wrapper gdmd), function literal always deduced as 'delegate'.
So this expression raises an error about type mismatching Lhs
of 'int function(int)' and Rhs of 'int delegate(int) pure
nothrow'.
Then, specifying explicit 'function' will resolve issue:
alg.funcio = function(int a) { return 2 * a; };
Bye.
Kenji Hara
Thanks, Kenji. If I change function to delegate in declaration
of field, it works too. What do you recommend to have
delegates or functions? What are the benefits and ...
Thanks,
Xan.
For an example, you can't use function-pointer to access
non-static methods, while with delegates you can. You can see
some examples on http://www.dlang.org (Languate Reference).
So, I deduce it's better to use delegater than function?
Re: Templates in classes => what is wrong?
On Tuesday, 17 April 2012 at 14:57:18 UTC, Xan wrote:
On Tuesday, 17 April 2012 at 01:31:43 UTC, Kenji Hara wrote:
On Monday, 16 April 2012 at 18:48:52 UTC, Xan wrote:
On Sunday, 15 April 2012 at 19:30:27 UTC, Ali Çehreli wrote:
On 04/15/2012 11:39 AM, Xan wrote:
> On Sunday, 15 April 2012 at 11:23:37 UTC, John Chapman
> wrote:
>> On Sunday, 15 April 2012 at 11:16:43 UTC, Xan wrote:
>>>
>>> int main(string [] args)
>>> {
>>> auto alg = Algorisme!(int,int);
>>
>> Should be:
>> auto alg = new Algorisme!(int, int);
>>
>>> alg.nom = "Doblar";
>>> alg.versio = 1;
>>> alg.funcio = (int a) {return 2*a};
>>
>> Should be:
>> alg.funcio = (int a) { return 2 * a; };
>> or:
>> alg.funcio = a => 2 * a;
>>
>>> }
>
>
> It does not work:
>
> $ gdmd-4.6 algorisme.d
> algorisme.d:18: Error: variable algorisme.main.alg voids
> have
no value
> algorisme.d:18: Error: expression class Algorisme is void
> and
has no value
>
> with the code https://gist.github.com/2394274
>
> What fails now?
>
> Thanks,
> Xan.
Your code is still missing 'new':
auto alg = new Algorisme!(int, int);
With only this change, I receive this error:
$ gdmd-4.6 algorisme.d
algorisme.d:21: Error: cannot implicitly convert expression
(__dgliteral1) of type int delegate(int a) pure nothrow to
int function(int)
Unrelated recommendations:
- Return 0 from main() for successful exit, anything else by
convention means some sort of error.
- Take advantage of constructors (and 'alias') to simplify
syntax and risk of bugs:
import std.conv, std.stdio, std.stream, std.string;
import std.socket, std.socketstream;
import std.datetime;
class Algorisme(U,V) {
string nom;
uint versio;
alias V function (U) Funcio;
Funcio funcio;
this(string nom, uint versio, Funcio funcio)
{
this.nom = nom;
this.versio = versio;
this.funcio = funcio;
}
}
int main(string [] args)
{
alias Algorisme!(int, int) MeuAlgorism;
auto alg = new MeuAlgorism("Doblar", 1,
(int a) { return 2 * a; });
return 0;
}
Ali
With all of your suggestion
[https://gist.github.com/2394274], I get:
$ gdmd-4.6 algorisme.d
algorisme.d:30: Error: constructor
algorisme.Algorisme!(int,int).Algorisme.this (string nom,
uint versio, int function(int) funcio) is not callable using
argument types (string,int,int delegate(int a) pure nothrow)
algorisme.d:30: Error: cannot implicitly convert expression
(__dgliteral1) of type int delegate(int a) pure nothrow to
int function(int)
algorisme.d:27: Error: function D main has no return
statement, but is expected to return a value of type int
What fails?
PS: Thanks for your recommendations...
PPS: By the other hand, I see you have learned catalan
("MeuAlgorisme"?) ;-)
Problem may be here:
alg.funcio = (int a) { return 2 * a; };
2.057 and earlier (You may use gdc 2.057 and command line
wrapper gdmd), function literal always deduced as 'delegate'.
So this expression raises an error about type mismatching Lhs
of 'int function(int)' and Rhs of 'int delegate(int) pure
nothrow'.
Then, specifying explicit 'function' will resolve issue:
alg.funcio = function(int a) { return 2 * a; };
Bye.
Kenji Hara
Thanks, Kenji. If I change function to delegate in declaration
of field, it works too. What do you recommend to have delegates
or functions? What are the benefits and ...
Thanks,
Xan.
For an example, you can't use function-pointer to access
non-static methods, while with delegates you can. You can see
some examples on http://www.dlang.org (Languate Reference).
Re: Templates in classes => what is wrong?
Off-topic, could can I define toString having this structure:
(versió ): ->
,
?
(For example, in https://gist.github.com/2394274 I want that
Doblar displays as:
Doblar (versió 1): int -> int, { return 2 * a; }
Thanks a lot,
Xan.
Re: Templates in classes => what is wrong?
On Tuesday, 17 April 2012 at 01:31:43 UTC, Kenji Hara wrote:
On Monday, 16 April 2012 at 18:48:52 UTC, Xan wrote:
On Sunday, 15 April 2012 at 19:30:27 UTC, Ali Çehreli wrote:
On 04/15/2012 11:39 AM, Xan wrote:
> On Sunday, 15 April 2012 at 11:23:37 UTC, John Chapman
> wrote:
>> On Sunday, 15 April 2012 at 11:16:43 UTC, Xan wrote:
>>>
>>> int main(string [] args)
>>> {
>>> auto alg = Algorisme!(int,int);
>>
>> Should be:
>> auto alg = new Algorisme!(int, int);
>>
>>> alg.nom = "Doblar";
>>> alg.versio = 1;
>>> alg.funcio = (int a) {return 2*a};
>>
>> Should be:
>> alg.funcio = (int a) { return 2 * a; };
>> or:
>> alg.funcio = a => 2 * a;
>>
>>> }
>
>
> It does not work:
>
> $ gdmd-4.6 algorisme.d
> algorisme.d:18: Error: variable algorisme.main.alg voids
> have
no value
> algorisme.d:18: Error: expression class Algorisme is void
> and
has no value
>
> with the code https://gist.github.com/2394274
>
> What fails now?
>
> Thanks,
> Xan.
Your code is still missing 'new':
auto alg = new Algorisme!(int, int);
With only this change, I receive this error:
$ gdmd-4.6 algorisme.d
algorisme.d:21: Error: cannot implicitly convert expression
(__dgliteral1) of type int delegate(int a) pure nothrow to int
function(int)
Unrelated recommendations:
- Return 0 from main() for successful exit, anything else by
convention means some sort of error.
- Take advantage of constructors (and 'alias') to simplify
syntax and risk of bugs:
import std.conv, std.stdio, std.stream, std.string;
import std.socket, std.socketstream;
import std.datetime;
class Algorisme(U,V) {
string nom;
uint versio;
alias V function (U) Funcio;
Funcio funcio;
this(string nom, uint versio, Funcio funcio)
{
this.nom = nom;
this.versio = versio;
this.funcio = funcio;
}
}
int main(string [] args)
{
alias Algorisme!(int, int) MeuAlgorism;
auto alg = new MeuAlgorism("Doblar", 1,
(int a) { return 2 * a; });
return 0;
}
Ali
With all of your suggestion [https://gist.github.com/2394274],
I get:
$ gdmd-4.6 algorisme.d
algorisme.d:30: Error: constructor
algorisme.Algorisme!(int,int).Algorisme.this (string nom, uint
versio, int function(int) funcio) is not callable using
argument types (string,int,int delegate(int a) pure nothrow)
algorisme.d:30: Error: cannot implicitly convert expression
(__dgliteral1) of type int delegate(int a) pure nothrow to int
function(int)
algorisme.d:27: Error: function D main has no return
statement, but is expected to return a value of type int
What fails?
PS: Thanks for your recommendations...
PPS: By the other hand, I see you have learned catalan
("MeuAlgorisme"?) ;-)
Problem may be here:
alg.funcio = (int a) { return 2 * a; };
2.057 and earlier (You may use gdc 2.057 and command line
wrapper gdmd), function literal always deduced as 'delegate'.
So this expression raises an error about type mismatching Lhs
of 'int function(int)' and Rhs of 'int delegate(int) pure
nothrow'.
Then, specifying explicit 'function' will resolve issue:
alg.funcio = function(int a) { return 2 * a; };
Bye.
Kenji Hara
Thanks, Kenji. If I change function to delegate in declaration of
field, it works too. What do you recommend to have delegates or
functions? What are the benefits and ...
Thanks,
Xan.
Re: Templates in classes => what is wrong?
On Monday, 16 April 2012 at 18:48:52 UTC, Xan wrote:
On Sunday, 15 April 2012 at 19:30:27 UTC, Ali Çehreli wrote:
On 04/15/2012 11:39 AM, Xan wrote:
> On Sunday, 15 April 2012 at 11:23:37 UTC, John Chapman wrote:
>> On Sunday, 15 April 2012 at 11:16:43 UTC, Xan wrote:
>>>
>>> int main(string [] args)
>>> {
>>> auto alg = Algorisme!(int,int);
>>
>> Should be:
>> auto alg = new Algorisme!(int, int);
>>
>>> alg.nom = "Doblar";
>>> alg.versio = 1;
>>> alg.funcio = (int a) {return 2*a};
>>
>> Should be:
>> alg.funcio = (int a) { return 2 * a; };
>> or:
>> alg.funcio = a => 2 * a;
>>
>>> }
>
>
> It does not work:
>
> $ gdmd-4.6 algorisme.d
> algorisme.d:18: Error: variable algorisme.main.alg voids have
no value
> algorisme.d:18: Error: expression class Algorisme is void and
has no value
>
> with the code https://gist.github.com/2394274
>
> What fails now?
>
> Thanks,
> Xan.
Your code is still missing 'new':
auto alg = new Algorisme!(int, int);
With only this change, I receive this error:
$ gdmd-4.6 algorisme.d
algorisme.d:21: Error: cannot implicitly convert expression
(__dgliteral1) of type int delegate(int a) pure nothrow to int
function(int)
Unrelated recommendations:
- Return 0 from main() for successful exit, anything else by
convention means some sort of error.
- Take advantage of constructors (and 'alias') to simplify
syntax and risk of bugs:
import std.conv, std.stdio, std.stream, std.string;
import std.socket, std.socketstream;
import std.datetime;
class Algorisme(U,V) {
string nom;
uint versio;
alias V function (U) Funcio;
Funcio funcio;
this(string nom, uint versio, Funcio funcio)
{
this.nom = nom;
this.versio = versio;
this.funcio = funcio;
}
}
int main(string [] args)
{
alias Algorisme!(int, int) MeuAlgorism;
auto alg = new MeuAlgorism("Doblar", 1,
(int a) { return 2 * a; });
return 0;
}
Ali
With all of your suggestion [https://gist.github.com/2394274],
I get:
$ gdmd-4.6 algorisme.d
algorisme.d:30: Error: constructor
algorisme.Algorisme!(int,int).Algorisme.this (string nom, uint
versio, int function(int) funcio) is not callable using
argument types (string,int,int delegate(int a) pure nothrow)
algorisme.d:30: Error: cannot implicitly convert expression
(__dgliteral1) of type int delegate(int a) pure nothrow to int
function(int)
algorisme.d:27: Error: function D main has no return statement,
but is expected to return a value of type int
What fails?
PS: Thanks for your recommendations...
PPS: By the other hand, I see you have learned catalan
("MeuAlgorisme"?) ;-)
Problem may be here:
alg.funcio = (int a) { return 2 * a; };
2.057 and earlier (You may use gdc 2.057 and command line wrapper
gdmd), function literal always deduced as 'delegate'. So this
expression raises an error about type mismatching Lhs of 'int
function(int)' and Rhs of 'int delegate(int) pure nothrow'.
Then, specifying explicit 'function' will resolve issue:
alg.funcio = function(int a) { return 2 * a; };
Bye.
Kenji Hara
Re: Templates in classes => what is wrong?
On 04/16/2012 11:48 AM, Xan wrote:
On Sunday, 15 April 2012 at 19:30:27 UTC, Ali Çehreli wrote:
On 04/15/2012 11:39 AM, Xan wrote:
> On Sunday, 15 April 2012 at 11:23:37 UTC, John Chapman wrote:
>> On Sunday, 15 April 2012 at 11:16:43 UTC, Xan wrote:
>>>
>>> int main(string [] args)
>>> {
>>> auto alg = Algorisme!(int,int);
>>
>> Should be:
>> auto alg = new Algorisme!(int, int);
>>
>>> alg.nom = "Doblar";
>>> alg.versio = 1;
>>> alg.funcio = (int a) {return 2*a};
>>
>> Should be:
>> alg.funcio = (int a) { return 2 * a; };
>> or:
>> alg.funcio = a => 2 * a;
>>
>>> }
>
>
> It does not work:
>
> $ gdmd-4.6 algorisme.d
> algorisme.d:18: Error: variable algorisme.main.alg voids have
no value
> algorisme.d:18: Error: expression class Algorisme is void and
has no value
>
> with the code https://gist.github.com/2394274
>
> What fails now?
>
> Thanks,
> Xan.
Your code is still missing 'new':
auto alg = new Algorisme!(int, int);
With only this change, I receive this error:
$ gdmd-4.6 algorisme.d
algorisme.d:21: Error: cannot implicitly convert expression
(__dgliteral1) of type int delegate(int a) pure nothrow to int
function(int)
Unrelated recommendations:
- Return 0 from main() for successful exit, anything else by
convention means some sort of error.
- Take advantage of constructors (and 'alias') to simplify syntax and
risk of bugs:
import std.conv, std.stdio, std.stream, std.string;
import std.socket, std.socketstream;
import std.datetime;
class Algorisme(U,V) {
string nom;
uint versio;
alias V function (U) Funcio;
Funcio funcio;
this(string nom, uint versio, Funcio funcio)
{
this.nom = nom;
this.versio = versio;
this.funcio = funcio;
}
}
int main(string [] args)
{
alias Algorisme!(int, int) MeuAlgorism;
auto alg = new MeuAlgorism("Doblar", 1,
(int a) { return 2 * a; });
return 0;
}
Ali
With all of your suggestion [https://gist.github.com/2394274], I get:
$ gdmd-4.6 algorisme.d
algorisme.d:30: Error: constructor
algorisme.Algorisme!(int,int).Algorisme.this (string nom, uint versio,
int function(int) funcio) is not callable using argument types
(string,int,int delegate(int a) pure nothrow)
algorisme.d:30: Error: cannot implicitly convert expression
(__dgliteral1) of type int delegate(int a) pure nothrow to int
function(int)
algorisme.d:27: Error: function D main has no return statement, but is
expected to return a value of type int
What fails?
Sorry to hear that it is still broken. I've only now realized that you
are using gdmd. Your code works with dmd 2.059 with just one fix:
Make the return type of main() void:
void main(string [] args)
PS: Thanks for your recommendations...
PPS: By the other hand, I see you have learned catalan ("MeuAlgorisme"?)
;-)
Google Translate helped me there. :)
Ali
Re: Templates in classes => what is wrong?
On Sunday, 15 April 2012 at 19:30:27 UTC, Ali Çehreli wrote:
On 04/15/2012 11:39 AM, Xan wrote:
> On Sunday, 15 April 2012 at 11:23:37 UTC, John Chapman wrote:
>> On Sunday, 15 April 2012 at 11:16:43 UTC, Xan wrote:
>>>
>>> int main(string [] args)
>>> {
>>> auto alg = Algorisme!(int,int);
>>
>> Should be:
>> auto alg = new Algorisme!(int, int);
>>
>>> alg.nom = "Doblar";
>>> alg.versio = 1;
>>> alg.funcio = (int a) {return 2*a};
>>
>> Should be:
>> alg.funcio = (int a) { return 2 * a; };
>> or:
>> alg.funcio = a => 2 * a;
>>
>>> }
>
>
> It does not work:
>
> $ gdmd-4.6 algorisme.d
> algorisme.d:18: Error: variable algorisme.main.alg voids have
no value
> algorisme.d:18: Error: expression class Algorisme is void and
has no value
>
> with the code https://gist.github.com/2394274
>
> What fails now?
>
> Thanks,
> Xan.
Your code is still missing 'new':
auto alg = new Algorisme!(int, int);
With only this change, I receive this error:
$ gdmd-4.6 algorisme.d
algorisme.d:21: Error: cannot implicitly convert expression
(__dgliteral1) of type int delegate(int a) pure nothrow to int
function(int)
Unrelated recommendations:
- Return 0 from main() for successful exit, anything else by
convention means some sort of error.
- Take advantage of constructors (and 'alias') to simplify
syntax and risk of bugs:
import std.conv, std.stdio, std.stream, std.string;
import std.socket, std.socketstream;
import std.datetime;
class Algorisme(U,V) {
string nom;
uint versio;
alias V function (U) Funcio;
Funcio funcio;
this(string nom, uint versio, Funcio funcio)
{
this.nom = nom;
this.versio = versio;
this.funcio = funcio;
}
}
int main(string [] args)
{
alias Algorisme!(int, int) MeuAlgorism;
auto alg = new MeuAlgorism("Doblar", 1,
(int a) { return 2 * a; });
return 0;
}
Ali
With all of your suggestion [https://gist.github.com/2394274], I
get:
$ gdmd-4.6 algorisme.d
algorisme.d:30: Error: constructor
algorisme.Algorisme!(int,int).Algorisme.this (string nom, uint
versio, int function(int) funcio) is not callable using argument
types (string,int,int delegate(int a) pure nothrow)
algorisme.d:30: Error: cannot implicitly convert expression
(__dgliteral1) of type int delegate(int a) pure nothrow to int
function(int)
algorisme.d:27: Error: function D main has no return statement,
but is expected to return a value of type int
What fails?
PS: Thanks for your recommendations...
PPS: By the other hand, I see you have learned catalan
("MeuAlgorisme"?) ;-)
Re: Templates in classes => what is wrong?
On 04/15/2012 01:27 PM, jerro wrote: - Return 0 from main() for successful exit, anything else by convention means some sort of error. Why not just declare main return type to be void? That's much better. :) D takes care of doing the right thing in that case. Ali
Re: Templates in classes => what is wrong?
- Return 0 from main() for successful exit, anything else by convention means some sort of error. Why not just declare main return type to be void?
Re: Templates in classes => what is wrong?
On 04/15/2012 11:39 AM, Xan wrote:
> On Sunday, 15 April 2012 at 11:23:37 UTC, John Chapman wrote:
>> On Sunday, 15 April 2012 at 11:16:43 UTC, Xan wrote:
>>>
>>> int main(string [] args)
>>> {
>>> auto alg = Algorisme!(int,int);
>>
>> Should be:
>> auto alg = new Algorisme!(int, int);
>>
>>> alg.nom = "Doblar";
>>> alg.versio = 1;
>>> alg.funcio = (int a) {return 2*a};
>>
>> Should be:
>> alg.funcio = (int a) { return 2 * a; };
>> or:
>> alg.funcio = a => 2 * a;
>>
>>> }
>
>
> It does not work:
>
> $ gdmd-4.6 algorisme.d
> algorisme.d:18: Error: variable algorisme.main.alg voids have no value
> algorisme.d:18: Error: expression class Algorisme is void and has no
value
>
> with the code https://gist.github.com/2394274
>
> What fails now?
>
> Thanks,
> Xan.
Your code is still missing 'new':
auto alg = new Algorisme!(int, int);
Unrelated recommendations:
- Return 0 from main() for successful exit, anything else by convention
means some sort of error.
- Take advantage of constructors (and 'alias') to simplify syntax and
risk of bugs:
import std.conv, std.stdio, std.stream, std.string;
import std.socket, std.socketstream;
import std.datetime;
class Algorisme(U,V) {
string nom;
uint versio;
alias V function (U) Funcio;
Funcio funcio;
this(string nom, uint versio, Funcio funcio)
{
this.nom = nom;
this.versio = versio;
this.funcio = funcio;
}
}
int main(string [] args)
{
alias Algorisme!(int, int) MeuAlgorism;
auto alg = new MeuAlgorism("Doblar", 1,
(int a) { return 2 * a; });
return 0;
}
Ali
Re: Templates in classes => what is wrong?
On Sunday, 15 April 2012 at 11:23:37 UTC, John Chapman wrote:
On Sunday, 15 April 2012 at 11:16:43 UTC, Xan wrote:
int main(string [] args)
{
auto alg = Algorisme!(int,int);
Should be:
auto alg = new Algorisme!(int, int);
alg.nom = "Doblar";
alg.versio = 1;
alg.funcio = (int a) {return 2*a};
Should be:
alg.funcio = (int a) { return 2 * a; };
or:
alg.funcio = a => 2 * a;
}
It does not work:
$ gdmd-4.6 algorisme.d
algorisme.d:18: Error: variable algorisme.main.alg voids have no
value
algorisme.d:18: Error: expression class Algorisme is void and has
no value
with the code https://gist.github.com/2394274
What fails now?
Thanks,
Xan.
Re: Templates in classes => what is wrong?
On Sunday, 15 April 2012 at 11:16:43 UTC, Xan wrote:
int main(string [] args)
{
auto alg = Algorisme!(int,int);
Should be:
auto alg = new Algorisme!(int, int);
alg.nom = "Doblar";
alg.versio = 1;
alg.funcio = (int a) {return 2*a};
Should be:
alg.funcio = (int a) { return 2 * a; };
or:
alg.funcio = a => 2 * a;
}
Templates in classes => what is wrong?
hi,
I have this code:
import std.conv, std.stdio, std.stream, std.string;
import std.socket, std.socketstream;
import std.datetime;
class Algorisme(U,V) {
string nom;
uint versio;
V delegate (U) funcio;
}
int main(string [] args)
{
auto alg = Algorisme!(int,int);
alg.nom = "Doblar";
alg.versio = 1;
alg.funcio = (int a) {return 2*a};
}
but when I compile I receive errors:
$ gdmd-4.6 algorisme.d
algorisme.d:22: found '}' when expecting ';' following return
statement
algorisme.d:25: found 'EOF' when expecting ';' following statement
algorisme.d:25: found 'EOF' when expecting '}' following compound
statement
What is wrong?
Thanks in advance,
Xan.
