Re: [fpc-pascal] Need some advice
Oh I didn't notice the typo, duh. Thanks!! On 1/24/24 02:57PM, Sven Barth via fpc-pascal wrote: ppadilcdx via fpc-pascal schrieb am Mi., 24. Jan. 2024, 22:07: Thanks for that, now it compiles but it doesn't work, i.e. I added a pair and value and then used trygetdata and it can't find it. So perhaps I'm missing something else : Your operator needs to establish a true order between the two passed in values. Right now your operators only check a, but not b. That is wrong and thus the map won't work correctly. Regards, Sven ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org https://lists.freepascal.org/cgi-bin/mailman/listinfo/fpc-pascal ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org https://lists.freepascal.org/cgi-bin/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] Need some advice
ppadilcdx via fpc-pascal schrieb am Mi., 24. Jan. 2024, 22:07: > Thanks for that, now it compiles but it doesn't work, i.e. I added a > pair and value and then used trygetdata and it can't find it. So perhaps > I'm missing something else : > Your operator needs to establish a true order between the two passed in values. Right now your operators only check a, but not b. That is wrong and thus the map won't work correctly. Regards, Sven ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org https://lists.freepascal.org/cgi-bin/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] Need some advice
Thanks for that, now it compiles but it doesn't work, i.e. I added a
pair and value and then used trygetdata and it can't find it. So perhaps
I'm missing something else :
program test;
{$mode objfpc}
{$modeswitch advancedrecords}
uses
fgl;
type
pair = record
x, y : integer;
class operator > (a,b: pair) r:boolean;
class operator < (a,b: pair) r:boolean;
end;
class operator pair.< (a,b: pair) r:boolean;
begin
if a.x < a.y then
r := true
else
r := false;
end;
class operator pair.> (a,b: pair) r:boolean;
begin
if a.x > a.y then
r := true
else
r := false;
end;
function cmp(const a,b : pair) : LongInt;
begin
if a < b then
cmp := -1
else
if a > b then
cmp := 1
else
cmp := 0;
end;
type
TMyDict = specialize TFPGMap;
var
Dict: TMyDict;
key: pair;
Value: Integer;
flg: boolean;
begin
Dict := TMyDict.Create;
Dict.OnKeyCompare := @cmp;
key.x := 2;
key.y := 4;
Dict.Add(key, 99);
flg := Dict.trygetdata(key, Value);
writeln(flg);
writeln(Value);
Dict.Free;
end.
On 1/24/24 12:34PM, Luca Olivetti via fpc-pascal wrote:
El 24/1/24 a les 20:31, ppadilcdx via fpc-pascal ha escrit:
Trying to use the fgl unit, specifically the TFPGMap. Below is a
simple program I'm trying to compile; it gives me two errors:
fgl.pp(1582,18) Error: Operator is not overloaded: "pair" < "pair"
fgl.pp(1584,23) Error: Operator is not overloaded: "pair" > "pair"
add a {$Modeswitch advancedrecords} and use class operators
program test;
{$mode objfpc}
{$modeswitch advancedrecords}
uses
fgl;
type
pair = record
x, y : integer;
class operator < (a,b:pair):boolean;
class operator > (a,b:pair):boolean;
end;
operator < (a,b: pair) r:boolean;
class operator pair.<(a,b:pair):boolean;
begin
if a.x < a.y then
r := true
result:=true
else
r := false;
result:=false;
end;
bye
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Re: [fpc-pascal] Need some advice
El 24/1/24 a les 20:31, ppadilcdx via fpc-pascal ha escrit:
Trying to use the fgl unit, specifically the TFPGMap. Below is a
simple program I'm trying to compile; it gives me two errors:
fgl.pp(1582,18) Error: Operator is not overloaded: "pair" < "pair"
fgl.pp(1584,23) Error: Operator is not overloaded: "pair" > "pair"
add a {$Modeswitch advancedrecords} and use class operators
program test;
{$mode objfpc}
{$modeswitch advancedrecords}
uses
fgl;
type
pair = record
x, y : integer;
class operator < (a,b:pair):boolean;
class operator > (a,b:pair):boolean;
end;
operator < (a,b: pair) r:boolean;
class operator pair.<(a,b:pair):boolean;
begin
if a.x < a.y then
r := true
result:=true
else
r := false;
result:=false;
end;
bye
--
Luca
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[fpc-pascal] Need some advice
Trying to use the fgl unit, specifically the TFPGMap. Below is a
simple program I'm trying to compile; it gives me two errors:
fgl.pp(1582,18) Error: Operator is not overloaded: "pair" < "pair"
fgl.pp(1584,23) Error: Operator is not overloaded: "pair" > "pair"
program test;
{$mode objfpc}
uses
fgl;
type
pair = record
x, y : integer;
end;
operator < (a,b: pair) r:boolean;
begin
if a.x < a.y then
r := true
else
r := false;
end;
operator > (a,b: pair) r:boolean;
begin
if a.x > a.y then
r := true
else
r := false;
end;
function cmp(const a,b : pair) : LongInt;
begin
if a < b then
cmp := -1
else
if a > b then
cmp := 1
else
cmp := 0;
end;
type
TMyDict = specialize TFPGMap;
var
Dict: TMyDict;
key: pair;
Value: Integer;
begin
Dict := TMyDict.Create;
Dict.OnKeyCompare := @cmp;
key.x := 2;
key.y := 4;
Dict.Add(key, 99);
Value := Dict[key];
writeln(Value);
Dict.Free;
end.
Any advice appreciated. Thanks.
Pete
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