[Solved] RegEx: Remove spaces between...

[Espectr0]

Hola,
I want to remove spaces between { }, and try the following code:

Code: Pascal  [Select][+][-]

1. s := ReplaceRegExpr('\s+(?=[^{}]*\})', Text, '');
2.  

but it tells me that identifier is not recognized in pos 14.

What am I doing wrong?
If I'm not mistaken the expression is,

Code: Pascal  [Select][+][-]

1. \s+      # Match whitespace
2. (?=      # only if followed by...
3.  [^{}]*  # any number of characters except parentheses
4.  \}      # and a closing parenthesis
5. )        # End of lookahead assertion
6.  

Thanks!

[Fibonacci]

Code: Pascal  [Select][+][-]

1. uses uregexpr;
2.  
3. var
4.   s: string;
5.  
6. begin
7.   s := 'bla bla {    } bla bla';
8.   writeln('s = ', s);
9.  
10.   s := ReplaceRegExpr('{\s+}', s, '{}');
11.   writeln('s = ', s);
12.  
13.   readln;
14. end.    

s = bla bla {    } bla bla
s = bla bla {} bla bla

This removes any white chars, if you want only spaces then:

Code: Pascal  [Select][+][-]

1. s := ReplaceRegExpr('{ +}', s, '{}');

[Espectr0]

and if the string is:

"{  ab c } This is a Demo { x y z }"

I want:

"{abc} This is a Demo {xyz}"

How would it be?

[Fibonacci]

Code: Pascal  [Select][+][-]

1. uses SysUtils, Classes, uregexpr;
2.  
3. type
4.   tMustBeInClass = class
5.     function regreplace(ARegExpr: TRegExpr): RegExprString;
6.   end;
7.  
8. function tMustBeInClass.regreplace(ARegExpr: TRegExpr): RegExprString;
9. var
10.   s: string;
11. begin
12.   s := ARegExpr.Match[0];
13.   s := s.Replace(' ', '');
14.   result := s;
15. end;
16.  
17. var
18.   s, d: string;
19.   r: TRegExpr;
20.   m: tMustBeInClass;
21.  
22. begin
23.   s := '{  ab c } This is a Demo { x y z }';
24.   writeln('s = ', s);
25.  
26.   m := tMustBeInClass.Create;
27.  
28.   r := TRegExpr.Create('{[a-zA-Z0-9 ]*}');
29.   d := r.Replace(s, @m.regreplace);
30.  
31.   writeln('d = ', d);
32.  
33.   readln;
34. end.

s = {  ab c } This is a Demo { x y z }
d = {abc} This is a Demo {xyz}

That should do it. Ugly, but works.

I dont know why it wont accept just "dot" as "all chars". So you might want to add chars if needed. Other RegEx unit maybe would do it better.

EDIT: Better version

Code: Pascal  [Select][+][-]

1. uses SysUtils, Classes, uregexpr;
2.  
3. type
4.   tMustBeInClass = class
5.     function regreplace(ARegExpr: TRegExpr): RegExprString;
6.   end;
7.  
8. function tMustBeInClass.regreplace(ARegExpr: TRegExpr): RegExprString;
9. var
10.   s: string;
11. begin
12.   s := ARegExpr.Match[0];
13.   s := s.Replace(' ', '');
14.   result := s;
15. end;
16.  
17. var
18.   s, d: string;
19.   r: TRegExpr;
20.   m: tMustBeInClass;
21.  
22. begin
23.   s := '{  ab c } This is a Demo { x y z } {Foo    B-  A-R     }';
24.   writeln('s = ', s);
25.  
26.   m := tMustBeInClass.Create;
27.  
28.   r := TRegExpr.Create('({.*})');
29.   r.ModifierG := false;
30.   d := r.Replace(s, @m.regreplace);
31.  
32.   writeln('d = ', d);
33.  
34.   readln;
35. end.

s = {  ab c } This is a Demo { x y z } {Foo    B-  A-R     }
d = {abc} This is a Demo {xyz} {FooB-A-R}

[Fibonacci]

Ok, final version.

Code: Pascal  [Select][+][-]

1. uses uregexpr;
2.  
3. var
4.   s: string;
5.  
6. begin
7.   s := '{  ab c } This is a Demo { x y z }';
8.   writeln('s = ', s);
9.  
10.   s := ReplaceRegExpr('\s+(?=[^{}]*\})', s, '', [rroModifierG]);
11.   writeln('s = ', s);
12.  
13.   readln;
14. end.

s = {  ab c } This is a Demo { x y z } {some more test} {UPPER CASE}
s = {abc} This is a Demo {xyz} {somemoretest} {UPPERCASE}

Your RegEx was fine, you just missed rroModifierG.

[Espectr0]

I get this error:

"TRegExpr compile: unrecognized modifier (pos 14)." 

[Fibonacci]

Maybe this?

s := ReplaceRegExpr('\s+(?=[^{}]*})', s, '', [rroModifierG]);

Or update your FPC & RTL.

Both this and previous regexes are correct:
https://regex101.com/r/KvOeTq/1

Or if this doesnt work try my "EDIT: Better version" version

[Espectr0]

Same error
I'm using Lazarus 2.2.6, FPC 3.2.2.

[Fibonacci]

Try "Better version" from post #3.

If doesnt work update FPC to 3.3.1

[TRon]

Indeed fpc 3.3.1 is required to let the example code from Fibonacci that uses ReplaceRegExpr work. His example from the 3th post does seem to work as intended for me with fpc 3.2.2

[AlexTP]

You can copy the file
https://gitlab.com/freepascal.org/fpc/source/-/blob/main/packages/regexpr/src/regexpr.pas
from FPC 3.3 Git repo to the folder of your program. And try again with new Regex.

[Espectr0]

@Fibonacci, I will use your solution.

Thank you all!