Not overloading operator - pascal

Question

Good day, I'm doing some Codeforces exercises in my free time, and I had a problem to test if the user was a boy or a girl, well, my problem isn't that, i have just demonstrated the code.
While compiling my code in my computer ( I'm using version 3.0.4 for i386 ) i get no error, but codeforces gives me this error
program.pas(15,16) Error: Operator is not overloaded: "freq(Char;AnsiString):LongInt;" + "ShortInt"
program.pas(46,4) Fatal: There were 1 errors compiling module, stopping
The error wasn't clear enough to me, as the same script was perfectly compiled with my version.
The platform is using ( version 3.0.2 i386-Win32 ).
program A236;
uses wincrt, sysutils;
var
username : String;
function freq(char: char; username : String): Integer;
var
i: Integer;
begin
freq:= 0;
for i:= 1 to length(username) do
if char = username[i] then
freq:= freq + 1;
//writeln(freq);
end;
function OddUserName(username : String): Boolean;
var
i, counter: Integer;
begin
OddUserName:= false; // even
counter:= 0;
for i:= 1 to length(username) do
if freq(username[i], username) <> 1 then
delete(username, i, 1)
else
counter:= counter + 1;
if counter mod 2 <> 0 then
OddUserName:= true; // odd
//writeln(counter);
//writeln(OddUserName);
end;
begin
readln(username);
if not OddUserName(username) then
writeln('CHAT WITH HER!')
else
writeln('IGNORE HIM!');
//readkey();
end.
The error is supposed to be at this line probably :
function freq(character: char; username : String): Integer;
Thanks for everyone who helps.

Answer 1

Inside of a function, the function's name can be used as a substitute for using an explicit local variable or Result. freq() and OddUserName() are both doing that, but only freq() is using the function name as an operand on the right-hand side of an assignment. freq := freq + 1; should be a legal statement in modern Pascal compilers, see Why i can use function name in pascal as variable name without definition?.
However, it would seem the error message is suggesting that the failing compiler is treating freq in the statement freg + 1 as a function type and not as a local variable. That would explain why it is complaining about not being able to add a ShortInt with a function type.
So, you will have to use an explicit local variable instead, (or the special Result variable, if your compiler provides that), eg:
function freq(charToFind: char; username : String): Integer;
var
i, f: Integer;
begin
f := 0;
for i := 1 to Length(username) do
if charToFind = username[i] then
f := f + 1;
//writeln(f);
freq := f;
end;
function freq(charToFind: char; username : String): Integer;
var
i: Integer;
begin
Result := 0;
for i := 1 to Length(username) do
if charToFind = username[i] then
Result := Result + 1;
//writeln(f);
end;