Regex question
lazarus / 61-Beginners

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justnewbie · 2019-07-15 17:29

Hi guys,

I have this text:
Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i something
retvalue -1 anything anyt=55; nothing var1=5;
By using the RegExpr, I want to get the text in this form (ie. the
anything and nothing should be in a new line):
Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i something
retvalue -1 anything anyt=55; nothing var1=5;
The https://regex101.com/ site gives me the good result if I write the
\n\0 in the substitution field (see the attached picture).
But the Lazarus cannot handle it.

My code:
Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i reBefore :=
'(anything|nothing)';reAfter := '\n\0';Memo1.Text :=
ReplaceRegExpr(reBefore, Memo1.Text, reAfter, true);
This code doesn't do what I need. How can I solve this?

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engkin · 2019-07-15 17:35

replace '\n\0' with LineEnding

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justnewbie · 2019-07-15 17:41

Quote from: engkin on July 15, 2019, 07:35:37 pmreplace '\n\0' with
LineEnding
Do you mean
Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i reAfter :=
LineEnding;?
This doesn't work.

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engkin · 2019-07-15 17:49

Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i program
Project1; {$mode objfpc}{$H+} uses  RegExpr; var  s1:string='something
retvalue -1 anything anyt=55; nothing var1=5;';  s2, reBefore,
reAfter: String;begin  reBefore := '(anything|nothing)';  reAfter :=
LineEnding+'$0';  s2 := ReplaceRegExpr(reBefore, s1, reAfter, true); 
WriteLn(s2);  ReadLn;end.

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justnewbie · 2019-07-15 18:09

Great, thank you, works!
If I may ask, why did not work the original version? >> '\n\0'
What does '$0' mean?

Also, I tried this way
Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i reAfter :=
'\n$0';and it worked as well.

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engkin · 2019-07-15 18:41

Quote from: justnewbie on July 15, 2019, 08:09:03 pmGreat, thank you,
works!
why did not work the original version? >> '\n\0'
It did work, but did not give what you want.

Quote from: justnewbie on July 15, 2019, 08:09:03 pmWhat does '$0'
mean?
It refers to the text inside the brackets, in this expression it may
be anything or nothing. To see it, try this change:
Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i   reAfter
:= '-->$0<--';
Quote from: justnewbie on July 15, 2019, 08:09:03 pmAlso, I tried this
way
Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i reAfter :=
'\n$0';and it worked as well.
I just checked RegExpr code, it supports:
Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i      't':
Result := #$9;  // \t => tab (HT/TAB)     'n': Result := #$a;  // \n
=> newline (NL)     'r': Result := #$d;  // \r => carriage return
(CR)     'f': Result := #$c;  // \f => form feed (FF)     'a': Result
:= #$7;  // \a => alarm (bell) (BEL)     'e': Result := #$1b; // \e =>
escape (ESC)     'x': begin // \x: hex char

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justnewbie · 2019-07-15 18:47

Thank you for your help, engkin!

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justnewbie · 2019-07-16 09:58

Now I have a bit more complicated task.
In my example there is a loop "header" that is in 3 lines, and I need
it only in 1 line.
The original text:
Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i    string
something="";   bool anything=true;   for(int i=0;   i<var1;   i++)  
 {      string nothing=text[i];     }I want the for(int i=0; i<var1;
i++) in 1 line.
Important: I need it in a general formula, so eg. it can be either
for(int var2=x; var2<var3; var2++) or for(int var4=100; var4>=var1;
var4--) and similar ...

By using this regex for\s*\([^\n]+\n[^\n]+\n[^\n]+ I can get the loop
"header", but I don't know how could I get the result without those 2
\n (highlighted with orange).
Any help?

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engkin · 2019-07-16 11:35

To remove all line endings use:
Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i   reBefore
:= '([^\r\n]+)[\r\n]+';  reAfter := '$1';  s2 :=
ReplaceRegExpr(reBefore, s1, reAfter, true);
To remove the two line endings in a for statement:
Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i   reBefore
:= '(for\s*\([^\r\n]+)[\r\n]+([^\r\n]+)[\r\n]+([^\r\n]+\))';  reAfter
:= '$1$2$3';  s2 := ReplaceRegExpr(reBefore, s1, reAfter, true);

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justnewbie · 2019-07-16 12:06

Thank you engkin, this is exactly what I need for!
(Soon I will have new question ...)

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justnewbie · 2019-07-16 14:19

New issue:
I need those lines that do not start with the word 'something'.
I know what ^something does, but I need for its opposite.

Edit: maybe I figured it out:
^[^\bsomething\b].*

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justnewbie · 2019-07-16 15:09

Next:

I have this text:
Quotemytext mytext hjsdgfjsh 57574 //gkgaksg
//  ztwojkgk
fjfjaf//tjtrjs
nodelete fghfgkhag //zrwjsj
ghfhfhd ://uzrutziut
I want to delete the texts in red (text after the //, together the //
itself), but I don't want to delete the texts in teal.
Ie., no delete if
1./ a line starts with nodelete
or
2./ there is a colon (:) right before the //

So I want to get this:
Quotemytext mytext hjsdgfjsh 57574

fjfjaf
nodelete fghfgkhag //zrwjsj
ghfhfhd ://uzrutziut
Update:
I found the solution for the 2. case:
(?<!:)\/\/[^\n]+[\n]+
I need to expand it with the 1. rule also.

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justnewbie · 2019-07-16 16:52

I found a solution:
(^(?!nodelete).*)(?<!:)\/\/[^\n]+[\n]+

It works well in the online regex tester https://regex101.com/, but
Lazarus gives an error (unrecognized modifier).
Any help?

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engkin · 2019-07-16 17:07

Probably time to consider using a different engine. For instance look
for FLRE.

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justnewbie · 2019-07-16 17:31

Quote from: engkin on July 16, 2019, 07:07:23 pmProbably time to
consider using a different engine. For instance look for FLRE.
What is it? I only found 'flare regular expr' in Google.
Can you provide me a link?

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engkin · 2019-07-16 18:15

https://github.com/BeRo1985/flre

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justnewbie · 2019-07-16 19:01

Quote from: engkin on July 16, 2019, 08:15:09
pmhttps://github.com/BeRo1985/flre
Uh, that's bad. I never used the github and don't know what should I
do with the downloaded zip.
Couldn't find install instructions.
Anyway, thanks.

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engkin · 2019-07-16 20:51

There are two files, FLRE.pas and PUCU.pas, need to be visible to your
project. Add their path to your project, or copy them to your folder.

For frequently used units, create a package, add them to the package,
and compile the it. Later on, when you need any of these units, add
the package to your project.

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justnewbie · 2019-07-16 21:00

Quote from: engkin on July 16, 2019, 10:51:12 pmThere are two files,
FLRE.pas and PUCU.pas, need to be visible to your project. Add their
path to your project, or copy them to your folder.

For frequently used units, create a package, add them to the package,
and compile the it. Later on, when you need any of these units, add
the package to your project.
I will give it a shot, thank you for your help!

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justnewbie · 2019-10-11 08:23

Hi guys/girls,
I am stuck with a regex problem, cannot figure it out.
This is the text:
Quote{
   First,//Something text
   Second,
   Small//Something text
   Big
}

I need to get the First, Second, Small and Big (highlighted with
Teal).
There are 3 spaces before them, but it can be any not just 3 (from 0
to infinity).
I tried this regex:
(?<=(^\s\s\s))(.*)(?=(,|\/\/|\n))
I doesn't work, see the image. Can anyone help me?

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bytebites · 2019-10-11 11:10

(?<=(\n(\s*)))([a-zA-Z]*)(?=([,/\n]))

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justnewbie · 2019-10-11 11:47

Quote from: bytebites on October 11, 2019, 01:10:31
pm(?<=(\n(\s*)))([a-zA-Z]*)(?=([,/\n]))
Thank you, but it gives pattern error:

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bytebites · 2019-10-11 12:01

https://regexr.com gives only a warning  about positive lookbehind.

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justnewbie · 2019-10-11 12:13

Quote from: bytebites on October 11, 2019, 02:01:21
pmhttps://regexr.com gives only a warning  about positive lookbehind.
I am using the https://regex101.com/, but tried the https://regexr.com
and it gives no matches but error:

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bytebites · 2019-10-11 13:01

The "positive lookbehind" feature may not be supported in all
browsers.

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justnewbie · 2019-10-11 13:23

Quote from: bytebites on October 11, 2019, 03:01:53 pmThe "positive
lookbehind" feature may not be supported in all browsers.
I need this thing in my Lazarus program, not in a browser.

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Leledumbo · 2019-10-11 14:04

Quote from: justnewbie on October 11, 2019, 10:23:32 amHi guys/girls,
I am stuck with a regex problem, cannot figure it out.
This is the text:
Quote{
   First,//Something text
   Second,
   Small//Something text
   Big
}

I need to get the First, Second, Small and Big (highlighted with
Teal).
There are 3 spaces before them, but it can be any not just 3 (from 0
to infinity).
I tried this regex:
(?<=(^\s\s\s))(.*)(?=(,|\/\/|\n))
I doesn't work, see the image. Can anyone help me?
That looks like a JSON so a JSON parser should work better.

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justnewbie · 2019-10-11 15:19

Thank you, but your advice is not an answer to my question.
I need the proper pattern that can be used in Lazarus.

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howardpc · 2019-10-11 16:42

This quick hack solution does not answer your regex question either,
but it does give a correct result.
Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i function
ParsedOK(aTxt: String; out s1, s2, s3, s4: String): Boolean;var  c:
SizeInt;  sl: TStringList;begin  Result := False;  s1 := ''; s2:= '';
s3 := ''; s4 := '';  aTxt := Trim(aTxt);  if (Length(aTxt) < 12) or
(aTxt[1] <> '{') or (aTxt[Length(aTxt)] <> '}') then    Exit;  sl :=
TStringList.Create;  try    sl.Text := aTxt;    if sl.Count <> 6 then 
    Exit;    c := Pos(',', sl[1]);    if c = 0 then      Exit;   
Dec(c);    s1 := Trim(Copy(sl[1], 1, c));     c := Pos(',', sl[2]);  
if c = 0 then      Exit;    Dec(c);    s2 := Trim(Copy(sl[2], 1,
c));     c := Pos('/', sl[3]);    if c = 0 then      Exit;    Dec(c); 
  s3 := Trim(Copy(sl[3], 1, c));     s4 := Trim(sl[4]);    Result :=
True;  finally    sl.Free;  end;end;

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justnewbie · 2019-10-11 16:50

Thank you, but unfortunately it is not good for me. I need REGEX.
(For example: I don't know in advance how many strings will be there,
the 4 is just an example. So, I need a general solution, regex can do
it.)

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ASerge · 2019-10-11 23:06

Quote from: justnewbie on October 11, 2019, 06:50:57 pmThank you, but
unfortunately it is not good for me. I need REGEX.
Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i {$MODE
OBJFPC}{$APPTYPE CONSOLE}{$LONGSTRINGS ON} uses RegExpr; procedure
Test(const S: string);var  R: TRegExpr;begin  R :=
TRegExpr.Create('');  try    R.ModifierM := True;    R.Expression :=
'^\W*(\w+)';    if R.Exec(S) then      repeat        Writeln('"',
R.Match[1], '"');      until not R.ExecNext;  finally    R.Free; 
end;end; const  CSampleInputText =    '{' + LineEnding +    '  
First,//Something text' + LineEnding +    '   Second,' + LineEnding + 
  '   Small//Something text' + LineEnding +    '   Big' + LineEnding
+    '}';begin  Test(CSampleInputText);  Readln;end.

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howardpc · 2019-10-12 09:19

Quote from: justnewbie on October 11, 2019, 06:50:57 pmI don't know in
advance how many strings will be there, the 4 is just an example. So,
I need a general solution, regex can do it.A more general (non-regex)
solution might be something like the following.
Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i program
ParseExample; {$AppType console}{$Mode objfpc}{$H+}        uses
Classes, SysUtils; const  txt = '{' + LineEnding +        '  
First,//Something text' + LineEnding +        '   Second,' +
LineEnding +        '                          extra                 
' + LineEnding +        '   Small//Something text' + LineEnding +    
  '   Big' + LineEnding + '}'; function
ParsedCommentToFirstWords(const aTxt: String; list: TStrings):
Boolean;     function FirstWord(const s: String): String;    var     
p, b: Integer;    begin      p := 1;      while (s[p] in [' ', #9])
and (p < Length(s)) do        Inc(p);      b := p;      while (s[p] in
['a'..'z','A'..'Z']) and (p < Length(s)) do        Inc(p);      case
(p = Length(s)) and (s[p] in ['a'..'z','A'..'Z']) of        True:
 Result := Copy(s, b, p-b+1);        False: Result := Copy(s, b,
p-b);      end;    end; var  i, min: Integer;begin  list.Text :=
Trim(aTxt);  if (list.Count < 3) or (Trim(list[0]) <> '{') or
(Trim(list[list.Count-1]) <> '}') then    Exit(False); 
list.Delete(0);  list.Delete(list.Count-1);  min := MaxInt;  for i :=
0 to list.Count-1 do    begin      list[i] := FirstWord(list[i]);    
if min > Length(list[i]) then        min := Length(list[i]);    end; 
Result := min > 0;end; var  sl: TStringList;  s: String;begin  sl :=
TStringList.Create;  if ParsedCommentToFirstWords(txt, sl) then    for
s in sl do      WriteLn(s)  else Writeln('invalid text format for
"',txt,'"');  sl.Free;end.

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justnewbie · 2019-10-14 20:33

Guys, thank you very much!

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justnewbie · 2019-10-15 13:49

Hi ASerge, I wish you were somewhere nearby ... 
I have a task that is too complicated for me (again! LOL). I spent
hours with it, but ...
I have a text and I need to get all the variable names (highlighted
with bold).
What is the proper REGEX pattern to get them? Have you any idea?
Quoteint something;
double anything=2.15;
int nothing  = 7;
string anytext, mytext="",poems;
int   x=7;int z; int w=85;
int k,q,e=2;

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Thaddy · 2019-10-15 14:02

Regular expressions are powerful, but that looks like something where
they are not in place.
It is much simpler to compare to a list of reserved words(int,double
etc, not something and family) and parse until white space or control
is met

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justnewbie · 2019-10-15 14:10

Quote from: Thaddy on October 15, 2019, 04:02:43 pmRegular expressions
are powerful, but that looks like something where they are not in
place.
It is much simpler to compare to a list of reserved words(int,double
etc, not something and family) and parse until white space or control
is met
I don't understand your post. I need to get the variable names
(something, anything etc ..) that are highlighted with bold.

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lucamar · 2019-10-15 14:30

Quote from: justnewbie on October 15, 2019, 04:10:36 pmQuote from:
Thaddy on October 15, 2019, 04:02:43 pmRegular expressions are
powerful, but that looks like something where they are not in place.
It is much simpler to compare to a list of reserved words(int,double
etc, not something and family) and parse until white space or control
is met
I don't understand your post. I need to get the variable names
(something, anything etc ..) that are highlighted with bold.

It means parsing out the known reserved words, numbers, etc. so that
you're left with the "unknown" ones, which are what you're after. For
example, parsing the second line: double anything=2.15; you first get
"double" which, being a reserved word, you can ignore; then you skip
the space(s) and get the word up to the symbol "=": you get "anything"
which is not a reserved word but comes after one, so it must be a
variable name, which is what you're looking for. Keep going on,
skipping the parts in which you're not interested, and you get your
list of variables as result.

It might help if you draw a BNF diagram of your lines; that allows you
to get a "feel" of what (and how) to parse "in" and what "out".

----------------------------------------------------------------------
justnewbie · 2019-10-15 14:40

Quote from: lucamar on October 15, 2019, 04:30:39 pmQuote from:
justnewbie on October 15, 2019, 04:10:36 pmQuote from: Thaddy on
October 15, 2019, 04:02:43 pmRegular expressions are powerful, but
that looks like something where they are not in place.
It is much simpler to compare to a list of reserved words(int,double
etc, not something and family) and parse until white space or control
is met
I don't understand your post. I need to get the variable names
(something, anything etc ..) that are highlighted with bold.

It means parsing out the known reserved words, numbers, etc. so that
you're left with the "unknown" ones, which are what you're after. For
example, parsing the second line: double anything=2.15; you first get
"double" which, being a reserved word, you can ignore; then you skip
the space(s) and get the word up to the symbol "=": you get "anything"
which is not a reserved word but comes after one, so it must be a
variable name, which is what you're looking for. Keep going on,
skipping the parts in which you're not interested, and you get your
list of variables as result.

It might help if you draw a BNF diagram of your lines; that allows you
to get a "feel" of what (and how) to parse "in" and what "out".
To be honest, I cannot imagine that there is no a much simpler way.
Think of it: there are hundreds of reserved words and characters (my
example is heavily simplified).

This is where I am now: I can get the "orange parts" that contain
those names (see picture). The pattern:
\b(int|double|string)(\s+)(.+)(  >> the smiley is a ; and )
But, I don't know how could I get ONLY the names.

----------------------------------------------------------------------
Thaddy · 2019-10-15 14:51

Quote from: justnewbie on October 15, 2019, 04:40:04 pmTo be honest, I
cannot imagine that there is no a much simpler way.
Think of it: there are hundreds of reserved words and characters (my
example is heavily simplified).
It is NOT that easy! As Lucamar confirmed.
For such tasks I usually write a compiler...
Don't be afraid, I mean I write a grammar and use plex and pyacc or
GoldParser to  generate the basic code.
In your case any C grammar would generate a correct lexer and parser
for your problem so you don't even have to write a grammar......

Now that is a "nice" answer to anyone that thinks simple things must
be easy to program..

There is a good example: the h2pas sourcecode. (I mean that: you have
to do all that)

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justnewbie · 2019-10-15 17:20

It can be done with 2 or 3 steps, see pictures.

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howardpc · 2019-10-15 17:59

A non-regex solution could be done by extending the list of allowed
type names in the following example.
I don't know if digits are allowed in your variable names. If so,
you'll need to adjust the parsing routine accordingly.
Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i program
project1; {$mode objfpc}{$H+}{$IfDef Windows}{$AppType
console}{$EndIf} uses  SysUtils, Types; function IsReserved(const
aWord: String): Boolean; // extend this for needed keywordsbegin  if
not Length(aWord) in [3, 6] then    Exit(False);  case
LowerCase(aWord) of    'int',    'string',    'double': Exit(True);  
else      Exit(False);  end;end; function GetVarNames(aTxt: String):
TStringDynArray;var  p: Integer = 1;  index: Integer = 0;  s:
String;   function GetNextWord: String; // assumes variable names must
be alphabetical  begin    Result := '';    while (p < Length(aTxt))
and not (aTxt[p] in ['A'..'Z','a'..'z']) do      Inc(p);    while (p <
Length(aTxt)) and (aTxt[p] in ['A'..'Z','a'..'z']) do      begin     
 Result := Result + aTxt[p];        Inc(p);      end;  end; begin 
SetLength(Result, Length(aTxt) shr 1);  aTxt := Trim(aTxt);  repeat  
s := GetNextWord;    case IsReserved(s) of      True: ;      False:  
    begin          Result[index] := s;          Inc(index);       
end;    end;  until s = '';  SetLength(Result, Pred(index));end; var 
txt: String = 'int something;'+LineEnding+                'double
anything=2.15;' + LineEnding +                'int nothing  = 7;' +
LineEnding +                'string anytext, mytext="",poems;' +
LineEnding +                'int   x=7;int z; int w=85;' + LineEnding
+                'int k,q,e=2;';  arr: TStringDynArray;  s:
String; begin  arr := GetVarNames(txt);  for s in arr do   
WriteLn(s);  WriteLn('Press [Enter] to finish');  ReadLn;end.This
outputsCode: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i
somethinganythingnothinganytextmytextpoemsxzwkqePress [Enter] to
finish

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Thaddy · 2019-10-15 18:17

That's extending white space...(but it neat code and maybe is a
solution)
The only proper solution is a parser.

----------------------------------------------------------------------
justnewbie · 2019-10-15 18:36

Thank you guys for the contribution!

----------------------------------------------------------------------
bytebites · 2019-10-15 19:36

Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i Result :=
Result + aTxt[p];This is slow.

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howardpc · 2019-10-22 14:32

A non-regex solution:
Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i program
project1; {$mode objfpc}{$H+}{$IfDef Windows}{$AppType
console}{$EndIf} uses  SysUtils; var  txt: String = 'Something
(anything nothing="hey!", anything something, nothing="hola!", thing)'
+                'something nothing="aloha!"';  sArr: TStringArray; 
s: String;  b, e, i: Integer;   function ExtractedBrackets(const aTxt:
String; out Brackets: TStringArray): Boolean;  var    p, pb: Integer; 
  bCount: Integer = 0;  begin    SetLength({%H-}Brackets, 0);   
Result := False;    p := 0;    while p < Length(aTxt) do      begin  
    Inc(p);        if (aTxt[p] = '(') and (bCount = 0) then         
begin            Inc(bCount);            pb := Succ(p);          end; 
      if (aTxt[p] = ')') and (bCount > 0) then          begin        
  SetLength(Brackets, Length(Brackets)+1);           
Brackets[High(Brackets)] := Copy(aTxt, pb, p-pb);           
Dec(bCount);            Result := True;          end;      end; 
end; function FoundBetweenPatternAndSeparator(aBegin: Integer; const
aTxt, aPattern: String; aSeparators: TSysCharSet; out Fragment:
String; out EndPos: Integer): Boolean;var  p, b: Integer;begin 
Fragment := '';  Result := False;  EndPos := 0;  p := Pos(aPattern,
aTxt, aBegin);  if p > 0 then    begin      Inc(p, Length(aPattern)); 
    b := p;      repeat        Inc(p);      until (p = Length(aTxt))
or (aTxt[p] in aSeparators);      if aTxt[p] in aSeparators then     
 begin          Fragment := Copy(aTxt, b, p-b);          EndPos :=
Succ(p);          Exit(True);        end;    end;end; begin  b := 1; 
if ExtractedBrackets(txt, sArr) then    for i := 0 to High(sArr) do  
  while FoundBetweenPatternAndSeparator(b, sArr[i], 'nothing=', [','],
s, e) do        begin          WriteLn(s);          b := e;       
end;  ReadLn;end.

----------------------------------------------------------------------
ASerge · 2019-10-22 21:04

Quote from: justnewbie on October 22, 2019, 01:00:52 pmI want to find
all occurences of a pattern in a text.
Requirements: follows the nothing= and has to be within brackets.
Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i {$MODE
OBJFPC}{$APPTYPE CONSOLE}{$LONGSTRINGS ON} uses RegExpr; procedure
Test(const S: string);var  ROut, RIn: TRegExpr;begin  ROut :=
TRegExpr.Create('\(([^\)]*)\)');  try    if ROut.Exec(S) then   
begin      RIn := TRegExpr.Create('nothing="([^"]+)"');      try     
 repeat          if RIn.Exec(ROut.Match[1]) then            repeat   
         Writeln(RIn.Match[1]);            until not RIn.ExecNext;   
   until not ROut.ExecNext;      finally        RIn.Free;      end;  
end;  finally    ROut.Free;  end;end; const  CSampleInputText =   
'Something (anything nothing="hey!", anything something,
nothing="hola!", thing)' + LineEnding +    'something
nothing="aloha!"' + LineEnding +    '(skip empty nothing="")' +
LineEnding +    '(other nothing="other!", nothing="again!",
thing)';begin  Test(CSampleInputText);  Readln;end.

----------------------------------------------------------------------
maurobio · 2019-11-05 10:46

Dear ALL,

I have strings with some embedded characters as follows:

s := '\i{}This is a string\i0{}'

I want to get rid of the \{} and \i0{} using the following regex:

e := '\\i\d*{}'

But when I attempt this:

n := ReplaceRegExpr(e, s, '', True);

I get the error:

TRegrExpr(comp): Nested *?+ (pos 6)

The above regex works in Python (as n = re.sub(e, '', s)), but
obviously the FPC implementation is different.

Could someone give me a hand?

Thanks in advance!

Best regards,

----------------------------------------------------------------------
Thaddy · 2019-11-05 10:51

I already replied in the other post: use an escape to escape a slash
\\

----------------------------------------------------------------------
maurobio · 2019-11-05 11:11

Thanks, @Thaddy!

----------------------------------------------------------------------
maurobio · 2019-11-05 11:18

... but when I changed the regex to:

e := '\\i\\d*{}'

I still get the same error (just one position changed):

TRegrExpr(comp): Nested *?+ (pos 7)

Any hints?

----------------------------------------------------------------------
bytebites · 2019-11-05 12:44

e:='\\i\d*\{}'

() is not needed.

----------------------------------------------------------------------
maurobio · 2019-11-05 20:03

@bitebyes:

There are no parentheses ('()') in my regex, those are braces ('{}'),
which are part of the string and that I want to get rid of.

Cheers,