Author: Jonas Bilinkevicius

How would I go about parsing TAB delimited text files? I'm having difficulty with 
the chr(9) character.

Answer:

Solve 1:

1   { ... }
2   var
3     t: Textfile;
4     line: string;
5     elements: TStringlist;
6   begin
7     Assignfile(t, filename);
8     Reset(t);
9     try
10      elements := TStringlist.Create;
11      try
12        while not Eof(t) do
13        begin
14          ReadLn(t, line);
15          {The following ignores empty lines}
16          if IScan(#9, line, 1) > 0 then
17          begin
18            elements.clear;
19            SplitString(line, #9, elements);
20            ProcessElements(elements); {you write this}
21          end;
22        end;
23      finally
24        elements.Free
25      end;
26    finally
27      Closefile(t);
28    end;
29  
30  {Return the position of the first instance of ch in S after position fromPos, or 0 
31  if ch was not found}
32  
33  function IScan(ch: Char; const S: string; fromPos: Integer): Integer;
34  var
35    i: Integer;
36  begin
37    Result := 0;
38    for i := fromPos to Length(S) do
39    begin
40      if S[i] = ch then
41      begin
42        Result := i;
43        Break;
44      end;
45    end;
46  end;
47  
48  {Split the passed string into substrings at the position of the separator character 
49  and add the substrings to the passed list. The list is not cleared first!}
50  
51  procedure SplitString(const S: string; separator: Char; substrings: TStrings);
52  var
53    i, n: Integer;
54  begin
55    if Assigned(substrings) and (Length(S) > 0) then
56    begin
57      i := 1;
58      repeat
59        n := IScan(separator, S, i);
60        if n = 0 then
61          n := Length(S) + 1;
62        substrings.Add(Copy(S, i, n - i));
63        i := n + 1;
64      until
65        i > Length(S);
66    end;
67  end;



Solve 2:
68  
69  procedure DelimitedListToStringList(const S: AnsiString; Delimiter: Char;
70    List: TStrings; NullValue: AnsiString);
71  var
72    iPos: Integer;
73    Temp, Temp1: AnsiString;
74  begin
75    if not Assigned(List) then
76      Exit;
77    List.Clear;
78    Temp := S;
79    iPos := Pos(Delimiter, S);
80    while iPos > 0 do
81    begin
82      SetLength(Temp1, iPos - 1);
83      Temp1 := Copy(Temp, 1, iPos - 1);
84      if Temp1 = '' then
85      begin
86        SetLength(Temp1, Length(NullValue));
87        Temp1 := NullValue;
88      end;
89      List.Add(Temp1);
90      Delete(Temp, 1, iPos);
91      iPos := Pos(Delimiter, Temp);
92    end;
93    if Temp > '' then
94      List.Add(Temp);
95  end;