Re: [fpc-pascal] Converting code from C++ to FP....
On Sat, Mar 19, 2011 at 06:07, Bo Berglund bo.bergl...@gmail.com wrote: 1) The second line in the loop contains the command std::max, how can that be translated? I have not found any class definition for std with a method max There is function Max in unit Math, so you could say: jBegin := Max(k-band, 1); 2) The parameter into the function is a pointer *A of type double. To me that indicates a value of some kind, but in the code it suddenly seems to appear as an array with indexing. What would be the proper pascal translation of this? Indeed. C doesn't actually have difference between pointer to some data and arrays. You could use open array: procedure Decompose(var A: array of double); ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] Converting code from C++ to FP....
Den 19-03-2011 08:30, Aleksa Todorovic skrev: 2) The parameter into the function is a pointer *A of type double. To me that indicates a value of some kind, but in the code it suddenly seems to appear as an array with indexing. What would be the proper pascal translation of this? Indeed. C doesn't actually have difference between pointer to some data and arrays. You could use open array: procedure Decompose(var A: array of double); Or you could use procedure Decompose(A: pdouble); That way it would be precisely the same as the C solution. You can array-index A the same way as in C(in some fpc modes) ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] Converting code from C++ to FP....
Jeppe Johansen jepj...@es.aau.dk wrote: Den 19-03-2011 08:30, Aleksa Todorovic skrev: 2) The parameter into the function is a pointer *A of type double. To me that indicates a value of some kind, but in the code it suddenly seems to appear as an array with indexing. What would be the proper pascal translation of this? Indeed. C doesn't actually have difference between pointer to some data and arrays. You could use open array: procedure Decompose(var A: array of double); Or you could use procedure Decompose(A: pdouble); That way it would be precisely the same as the C solution. You can array-index A the same way as in C(in some fpc modes) I would only do that when mixing C and Pascal code, to interface with C code. In a Pascal-only program, never. Converting bad C code (that means almost any C code) to good FPC code is a great thing to do, converting to bad FPC code is not as much fun. /Ingemar ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
[fpc-pascal] Re: Converting code from C++ to FP....
On Sat, 19 Mar 2011 08:30:45 +0100, Aleksa Todorovic alexi...@gmail.com wrote: On Sat, Mar 19, 2011 at 06:07, Bo Berglund bo.bergl...@gmail.com wrote: 1) The second line in the loop contains the command std::max, how can that be translated? I have not found any class definition for std with a method max There is function Max in unit Math, so you could say: jBegin := Max(k-band, 1); 2) The parameter into the function is a pointer *A of type double. To me that indicates a value of some kind, but in the code it suddenly seems to appear as an array with indexing. What would be the proper pascal translation of this? Indeed. C doesn't actually have difference between pointer to some data and arrays. You could use open array: procedure Decompose(var A: array of double); Thanks for the information! Now I have found another very strange construct: void ForwardModel::SetMixedBoundaryCondition(const int iElec, const double* SX0, const double* SY0, const double* SZ0, double* SX, double* SY, double* SZ) Now it seems like the variable type declaration itself is a pointer Instead of double *Name it is double* Name. What is the difference? It is still being used as an array: SX[n1] = SX0[n1] * (1.0 - w1); Does C++ allow any placement of the * operator with the same meaning? And what does const double* mean? Pointer to some object but not allowed to change that object Having programmed Delphi for 16 years this is hard to wrap ones head around. :-( -- Bo Berglund Developer in Sweden ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] Converting code from C++ to FP....
Ingemar Ragnemalm schrieb: Converting bad C code (that means almost any C code) to good FPC code is a great thing to do, converting to bad FPC code is not as much fun. Yes, when already in progress of converting to Pascal then get rid of C design flaws and convert to clear Pascal code. ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] Re: Converting code from C++ to FP....
On Sat, Mar 19, 2011 at 13:03, Bo Berglund bo.bergl...@gmail.com wrote: Now I have found another very strange construct: void ForwardModel::SetMixedBoundaryCondition(const int iElec, const double* SX0, const double* SY0, const double* SZ0, double* SX, double* SY, double* SZ) Now it seems like the variable type declaration itself is a pointer Instead of double *Name it is double* Name. What is the difference? It is still being used as an array: SX[n1] = SX0[n1] * (1.0 - w1); Does C++ allow any placement of the * operator with the same meaning? And what does const double* mean? Pointer to some object but not allowed to change that object Having programmed Delphi for 16 years this is hard to wrap ones head around. :-( Welcome to the world of Chell ;-) I (unfortunately) have to use it daily. Ok, not let's be helpful. In the situation above, const has similar meaning as the one in Pascal - you have some value which you are not allowed to change. So, your header should be something like: procedure ForwardModel.SetMixedBoundaryCondition(const iElec : Integer; const SX0, SY0, SZ0 : array of double; var SX, SY, SZ : array of double); Hint: if you use trunk version of FPC, I suggest you use constref to ensure SX0, SY0 and SZ0 are passed as pointer. procedure ForwardModel.SetMixedBoundaryCondition(const iElec : Integer; constref SX0, SY0, SZ0 : array of double; var SX, SY, SZ : array of double); As Jeppe suggested, you can also use pointers: procedure ForwardModel.SetMixedBoundaryCondition(const iElec : Integer; const SX0, SY0, SZ0 : pdouble; SX, SY, SZ : pdouble); ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] double dispatch
On 18 Mar 2011, at 22:47, Jorge Aldo G. de F. Junior wrote: Can FPC deal with double-dispatch ? No, because overloading works the same as in C++ (determined statically at compile time). Jonas___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
[fpc-pascal] Re: Converting code from C++ to FP....
On Sat, 19 Mar 2011 13:10:25 +0100, Jürgen Hestermann juergen.hesterm...@gmx.de wrote: Ingemar Ragnemalm schrieb: Converting bad C code (that means almost any C code) to good FPC code is a great thing to do, converting to bad FPC code is not as much fun. Yes, when already in progress of converting to Pascal then get rid of C design flaws and convert to clear Pascal code. That is indeed my aim! :-) -- Bo Berglund Developer in Sweden ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] Re: Converting code from C++ to FP....
no one explained so let me try : void ForwardModel::SetMixedBoundaryCondition(const int iElec, void somefunction means its a pascal procedure const double* SX0, const has the same effect as fpc const before a parameter, double* SX0 is the same as double *SX0 or double * SX0 so this becomes const SX0 : pdouble (ugly pointer as array Cishism) const double* SY0, const SY0 : pdouble const double* SZ0, idem double* SX, double* SY, double* SZ) SX : pdouble; etc ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
[fpc-pascal] Re: double dispatch
No, because overloading works the same as in C++ (determined statically at compile time). Are you sure, Jonas? Because I've been able to implement visitor pattern which is a kind of double dispatch. Of course it's not implemented like the example posted by the OP, but more like a simulation explained in http://en.wikipedia.org/wiki/Double_dispatch wikipedia . -- View this message in context: http://free-pascal-general.1045716.n5.nabble.com/double-dispatch-tp3987828p4072095.html Sent from the Free Pascal - General mailing list archive at Nabble.com. ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] Re: double dispatch
On 19 Mar 2011, at 15:58, leledumbo wrote: No, because overloading works the same as in C++ (determined statically at compile time). Are you sure, Jonas? Yes. Because I've been able to implement visitor pattern which is a kind of double dispatch. Of course it's not implemented like the example posted by the OP, but more like a simulation explained in http://en.wikipedia.org/wiki/Double_dispatch wikipedia . Exactly, it's an emulation: achieves the same effect without availability of double dispatch. Jonas___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] Re: double dispatch
In our previous episode, leledumbo said: No, because overloading works the same as in C++ (determined statically at compile time). Are you sure, Jonas? Because I've been able to implement visitor pattern which is a kind of double dispatch. Of course it's not implemented like the example posted by the OP, but more like a simulation explained in http://en.wikipedia.org/wiki/Double_dispatch wikipedia . That is purely statically typed based overloading as far as I can see, and doesn't switch methods at runtime. The only escape that I know to statically typed calling in FPC is IDispatch. ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
[fpc-pascal] Re: Converting code from C++ to FP....
On Sat, 19 Mar 2011 11:30:47 -0300, Jorge Aldo G. de F. Junior jagf...@gmail.com wrote: no one explained so let me try : void ForwardModel::SetMixedBoundaryCondition(const int iElec, void somefunction means its a pascal procedure const double* SX0, const has the same effect as fpc const before a parameter, double* SX0 is the same as double *SX0 or double * SX0 so this becomes const SX0 : pdouble (ugly pointer as array Cishism) const double* SY0, const SY0 : pdouble const double* SZ0, idem double* SX, double* SY, double* SZ) SX : pdouble; etc Thanks! :-) -- Bo Berglund Developer in Sweden ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
