Thread overview | ||||||||||||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
April 15, 2012 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. |
April 15, 2012 Re: Templates in classes => what is wrong? | ||||
---|---|---|---|---|
| ||||
Posted in reply to Xan | 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; > } |
April 15, 2012 Re: Templates in classes => what is wrong? | ||||
---|---|---|---|---|
| ||||
Posted in reply to John Chapman | 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. |
April 15, 2012 Re: Templates in classes => what is wrong? | ||||
---|---|---|---|---|
| ||||
Posted in reply to Xan | 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 |
April 15, 2012 Re: Templates in classes => what is wrong? | ||||
---|---|---|---|---|
| ||||
Posted in reply to Ali Çehreli | > - 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?
|
April 15, 2012 Re: Templates in classes => what is wrong? | ||||
---|---|---|---|---|
| ||||
Posted in reply to jerro | 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
|
April 16, 2012 Re: Templates in classes => what is wrong? | ||||
---|---|---|---|---|
| ||||
Posted in reply to Ali Çehreli | 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"?) ;-) |
April 16, 2012 Re: Templates in classes => what is wrong? | ||||
---|---|---|---|---|
| ||||
Posted in reply to Xan | 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 |
April 17, 2012 Re: Templates in classes => what is wrong? | ||||
---|---|---|---|---|
| ||||
Posted in reply to Xan | 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 |
April 17, 2012 Re: Templates in classes => what is wrong? | ||||
---|---|---|---|---|
| ||||
Posted in reply to Kenji Hara | 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.
|
Copyright © 1999-2021 by the D Language Foundation