[fpc-devel] Questions on TStringList.Find change (Mantis 28744)

[Denis Kozlov]

On 22 March 2016 at 14:43, Michael Van Canneyt wrote:

>
> On 3/22/16 2:01 AM, Michael Van Canneyt wrote:
>>
>>>
>>> There are now several options:
>>> 1. I change the code to raise an exception instead (as was my original
>>> plan)
>>> 2. I change the code to resort to a linear search if sorted is false.
>>> 3. I introduce a boolean property that determines whether Find does any
>>> check.
>>>    By default the check will be done, to warn people they're doing
>>>    something stupid. If they override the check, we can assume they know
>>> what
>>>    they are doing.
>>> 4. Combine 1 and 3.
>>>
>>> Or,
>>>
>>> 5. You override sort so it does nothing. It is virtual.
>>>    You can then set sorted to True, no sort will occur, and find will do
>>> it's job.
>>>
>>> 6. You use another TStringList where you change find to suit your needs.
>>>    All it takes for you is to copy the implementation, you can keep the
>>> same
>>>    name, and insert the unit after the classes unit in places where you
>>> need it.
>>>
>>
> That aside: I will probably go for 1 or 4.
>
> Michael.
>


Please consider the following implementation logic, I think it covers all
angles:

procedure Find(const S: string; out Index: Integer):Boolean;
begin
  if Sorted then
    Result := FindSorted(S, Index);
  else
  begin
    Index := IndexOf(S);
    Result := (Index >= 0);
  end;
end;

procedure FindSorted(const S: string; out Index: Integer; CheckSorted:
Boolean = True):Boolean;
begin
  if CheckSorted and not Sorted then
    raise Exception.Create('List must be sorted');
  // search logic here...
end;


Denis
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