Unwrapping lines in text

[zxandris]

Hi there,

I'm trying to create a routine that essentially un-wraps something i.e. when a line has a line break but the line directly under it has text.  But not if there is white space.  I think the proper term is repaginating but I'm not sure on that. I currently have :-

Code: Pascal  [Select][+][-]

1. procedure TfrmMain.actSelectReparagraphExecute(Sender: TObject);
2. var
3.    lst, lst2 : TStringList;
4.    a : Integer;
5.    txt : String;
6. begin
7.      lst := TStringList.create;
8.      try
9.         lst.text := GetEditorText;
10.         lst2 := TStringList.create;
11.         try
12.            a := 0;
13.            if lst.count-1<>-1 then
14.            begin
15.                txt := lst[0];
16.                while a<=lst.count - 1 do
17.                begin
18.                     if a+1<lst.count-1 then
19.                     begin
20.                          if trim(lst[a+1])<>'' then
21.                          begin
22.                              txt := txt + trim(lst[a+1]);
23. //                             a := succ(a);
24.                          end else
25.                          begin
26.                               lst2.add(txt);
27.                               lst2.add('');
28.                               txt := '';
29.                          end;
30.                     end else break;
31.                     a := succ(a);
32.                     if a>lst.count-1 then break;
33.                end;
34.                if txt<>'' then lst2.add(txt);
35.                setEditorText(lst2.text);
36.                memEdit.Modified := true;
37.            end;
38.         finally
39.                lst2.free;
40.         end;
41.      finally
42.             lst.free;
43.      end;
44.      SetCurrentFocus;
45. end;
46.  

Which only appears to work. If I've got say :-

Code: [Select]

This is a test, This is a test, This is a test, This
is a test, This is a test, This is a test, This is
a test, This is a test.

I get :-

Code: [Select]

This is a test, This is a test, This is a test, This is a test, This is a test, This is a test, This is

Which is wrong obviously.  I was hoping someone could help me with this please?

Thanks,

CJ

[zxandris]

Okay so I was a character out which is why it truncated, but I would imagine there is a better way of doing this no?

Code: Pascal  [Select][+][-]

1. function UnWrapLines(const str : String) : string;
2. var
3.    lst, lst2 : TStringList;
4.    a : Integer;
5.    txt : String;
6. begin
7.      lst := TStringList.create;
8.      try
9.         lst.text := str;
10.         lst2 := TStringList.create;
11.         try
12.            a := 0;
13.            if lst.count-1<>-1 then
14.            begin
15.                txt := lst[0];
16.                while a<=lst.count - 1 do
17.                begin
18.                     if a+1<=lst.count-1 then
19.                     begin
20.                          if trim(lst[a+1])<>'' then
21.                          begin
22.                              txt := txt + lst[a+1];
23.                          end else
24.                          begin
25.                               lst2.add(txt);
26.                               lst2.add('');
27.                               txt := '';
28.                          end;
29.                     end else break;
30.                     a := succ(a);
31.                     if a>lst.count-1 then break;
32.                end;
33.                if txt<>'' then lst2.add(txt);
34.            end;
35.            if trim(lst2.text)<>'' then result := lst2.text
36.            else result := '';
37.         finally
38.                lst2.free;
39.         end;
40.      finally
41.             lst.free;
42.      end;
43. end;
44.  

As you can see, I made it a function, tidies up my actual code a little lol.  But this seems somehow inelegant, and I would imagine there was a better way.  Is anyone willing to help me improve this?

[Roland57]

Hello!

If ever it can be useful, I use something like this, under Linux, for French text.

Code: Pascal  [Select][+][-]

1. uses
2.   RegExpr;
3.  
4. const
5.   CBefore = '\w|à|é|ù|,|\.|:|;|–|\?|!';
6.   CAfter = '\w|à|â|é|É|ê|œ|«';
7.  
8. var
9.   LText: string;
10.  
11. begin
12.   LText := ReplaceRegExpr('(' + CBefore + ')\x0A(' + CAfter + ')', LText, '$1 $2', TRUE);

[Khrys]

Using a regex like  /([^\n])\n(\S)/  with  /$1 $2/  as the substitution pattern is probably the shortest solution

[zxandris]

I must admit I've never used RegEx.  Is there a good source for information on that.  It seems, from what little I know, to be very useful.

[alpine]

If I got your intention right:

Code: Pascal  [Select][+][-]

1. procedure TfrmMain.actSelectReparagraphExecute(Sender: TObject);
2. var
3.    lst, lst2 : TStringList;
4.    a : Integer;
5.    txt : String;
6. begin
7.    lst := TStringList.create;
8.    try
9.       lst.text := GetEditorText;
10.       lst2 := TStringList.create;
11.       try
12.         if lst.count>0 then
13.         begin
14.           txt := lst[0];
15.           a := 1;
16.           while a<lst.count do
17.           begin
18.             if trim(lst[a])<>'' then
19.               txt := txt + trim(lst[a])
20.             else
21.             begin
22.               if txt<>'' then
23.               begin
24.                 lst2.add(txt);
25.                 lst2.add('');
26.               end;
27.               txt := '';
28.             end;
29.             a := succ(a);
30.           end;
31.           if txt<>'' then lst2.add(txt);
32.           setEditorText(lst2.text);
33.           memEdit.Modified := true;
34.         end;
35.       finally
36.         lst2.free;
37.       end;
38.    finally
39.      lst.free;
40.    end;
41.    SetCurrentFocus;
42. end;

[TRon]

I leave the separation details for OP (example assumes wrapped lines contains spaces between words, at all times/everywhere).

Code: Pascal  [Select][+][-]

1. function UnWrapLines(const str : string) : string;
2. var
3.   WrappedLines   : TStringList;
4.   WrappedLine    : string;
5.   UnwrappedLines : TStringList;
6.   UnWrappedLine  : string = '';
7. begin
8.   Result := '';
9.   WrappedLines   := TStringList.Create;
10.   UnWrappedLines := TStringList.Create;
11.  
12.   try
13.     WrappedLines.text := str;
14.  
15.     for WrappedLine in WrappedLines do
16.     begin
17.       if WrappedLine = '' then
18.       begin
19.         UnWrappedLines.Add(UnwrappedLine);
20.         UnWrappedLines.Add('');
21.         UnwrappedLine := '';
22.       end
23.       else
24.       begin
25.         UnwrappedLine := UnwrappedLine + WrappedLine;
26.       end;
27.     end;
28.  
29. // I forgot about this situation
30.     if Length(UnwrappedLine) > 0
31.       then UnWrappedLines.Add(UnwrappedLine);
32. // end of forgetfulness
33.  
34.     result := UnwrappedLines.Text;
35.   finally
36.     WrappedLines.Free;
37.     UnWrappedLines.Free;
38.   end;
39. end;
40.  

[zxandris]

Hey there I'm using, as my testing text

Code: [Select]

This is a test, This is a test, This is a test, This
is a test, This is a test, This is a test, This is
a test, This is a test. This is a test, This is a
test, This is a test, This is a test, This is a test,
This is a test, This is a test, This is a test.

And your solution doesn't appear to actually return anything?!  Am I doing it wrong?

I leave the separation details for OP (example assumes wrapped lines contains spaces between words, at all times/everywhere).

Code: Pascal  [Select][+][-]

1. function UnWrapLines(const str : string) : string;
2. var
3.   WrappedLines   : TStringList;
4.   WrappedLine    : string;
5.   UnwrappedLines : TStringList;
6.   UnWrappedLine  : string = '';
7. begin
8.   Result := '';
9.   WrappedLines   := TStringList.Create;
10.   UnWrappedLines := TStringList.Create;
11.  
12.   try
13.     WrappedLines.text := str;
14.  
15.     for WrappedLine in WrappedLines do
16.     begin
17.       if WrappedLine = '' then
18.       begin
19.         UnWrappedLines.Add(UnwrappedLine);
20.         UnWrappedLines.Add('');
21.         UnwrappedLine := '';
22.       end
23.       else
24.       begin
25.         UnwrappedLine := UnwrappedLine + WrappedLine;
26.       end;
27.     end;
28.     result := UnwrappedLines.Text;
29.   finally
30.     WrappedLines.Free;
31.     UnWrappedLines.Free;
32.   end;
33. end;
34.  

[TRon]

And your solution doesn't appear to actually return anything?!  Am I doing it wrong?

Sorry, my bad. I made the assumption there is always and "empty ending" marker

I have fixed my posted code by adding the line

Code: Pascal  [Select][+][-]

1.     if Length(UnwrappedLine) > 0
2.       then UnWrappedLines.Add(UnwrappedLine);
3.  

[Roland57]

My corrected solution, following Khrys' suggestion.

Code: Pascal  [Select][+][-]

1. uses
2.   RegExpr;
3.  
4. const
5.   CSample =
6.   'This is a test.' + LineEnding +
7.   'This is a test.' + LineEnding + LineEnding +
8.   'This is a test.' + LineEnding +
9.   'This is a test.' + LineEnding +
10.   '  This is a test.';
11.  
12.  
13.   CBefore = '[^\n]'; // One character that is not line ending
14.   CAfter = '[^\n\s]'; // One character that is neither line ending nor space
15.  
16. var
17.   LText: string;
18.  
19. begin
20.   LText := CSample;
21.   LText := ReplaceRegExpr('(' + CBefore + ')\n(' + CAfter + ')', LText, '$1 $2', TRUE);
22.   // Parentheses are for capturing.
23.   // TRUE => Enable substitution
24.   WriteLn(LText);
25. end.
26.  

Code: Text  [Select][+][-]

1. [roland@localhost regexpr]$ ./unwrap
2. This is a test. This is a test.
3.  
4. This is a test. This is a test.
5.   This is a test.
6.