parsing – delphi – strip out all non standard text characers from string – Stack Overflow
Posted by jpluimers on 2021/12/02
From a while back a totally non-optimised code example by me (intentionally limiting to AnsiStr as it was about filtering ASCII, and UniCode has way many code points for the Latin script).
// For those who need a disclaimer:
// This code is meant as a sample to show you how the basic check for non-ASCII characters goes
// It will give low performance with long strings that are called often.
// Use a TStringBuilder, or SetLength & Integer loop index to optimize.
// If you need really optimized code, pass this on to the FastCode people.
function StripNonAsciiExceptCRLF(const Value: AnsiString): AnsiString;
var
AnsiCh: AnsiChar;
begin
for AnsiCh in Value do
if (AnsiCh >= #32) and (AnsiCh <= #127) and (AnsiCh <> #13) and (AnsiCh <> #10) then
Result := Result + AnsiCh;
end;
and an optimised one by [WayBack] David Heffernan
function StrippedOfNonAscii(const s: string): string;
var
i, Count: Integer;
begin
SetLength(Result, Length(s));
Count := 0;
for i := 1 to Length(s) do begin
if ((s[i] >= #32) and (s[i] <= #127)) or (s[i] in [#10, #13]) then begin
inc(Count);
Result[Count] := s[i];
end;
end;
SetLength(Result, Count);
end;
Even when “trivial”, I usually do not prematurely optimise as optimised code is almost always less readable than non-optimised code.
Source: [Wayback] parsing – delphi – strip out all non standard text characers from string – Stack Overflow
–jeroen
The Wiert Corner - irregular stream of stuff 
Leave a comment