Tip

How to cull elements from a list using Formula

VIEW MEMBER FEEDACK TO THIS TIP

Whether it's because of ignorance or inexperience, I find that string and list handling are not completely covered in Formula language. I often find myself "inventing" functionality that would well defend a permanent place in Formula coding as a built-in function.

I offer to you a widget I sometimes use to cull elements from a list. I've dressed it up for testing. I would appreciate users testing this and responding with suggestions for improvements -- supposing that it is logically sound and fail-safe (I haven't really done that).

If this is already a built-in Formula feature, I haven't seen it thus far. But if it does already exist, I would appreciate any information you have about it.

REM {Keep only elements from one 
list not in the other list -- differentiate them. 
Place this code in an action button or paste the code 
into any text field on a form and enter CTRL+SHIFT+F9 
to execute the code. You may also increase usability by
 converting the lists to lowercase 
using @LowerCase before comparing, for example.};

REM {List1 is the original list in which you wish to keep 
only elements not present in List2, 
it replaces the elements in List2 with "" in List1};

list1 := @Prompt([OkCancelEdit]; 
"Enter list1"; "Please enter a list of elements";
 "summer, winter, spring" );

list1 := @Explode( list1 );

@Prompt([OK] ; "This is your list" ; 
@Implode( @Sort( @Trim( list1 ) ) ; @Newline ) );

list2 := @Prompt([OkCancelEdit]; 
"Which element(s) would you like to remove? 
(from List1)"; "Enter the element(s) here"; 
"summer, winter, leaf");

list2 := @Explode( list2 );

@Prompt([OK] ; "You wish to remove" ; 
@Trim(@Implode(list2 ; @Newline)) );

result := @Replace( list1 ; list2; "");

@Prompt([Ok] ; "Result"  ; 
"Remaining entries: " + @NewLine + 
@Implode(@Sort(result) ; @NewLine ) + 
@NewLine +  @NewLine + "Cleared:" + 
@NewLine + @NewLine + @Implode(@Sort(list2) ; 
@Newline ) + @NewLine + + @NewLine + "** from **" 
+ @NewLine + @NewLine + @Implode(@Sort(list1) ; @Newline) )

MEMBER FEEDBACK TO THIS TIP

You can also use:

@ReplaceSubstring( list1 ; list2 ; "" )) )

For example:

list1 := @Explode( "summer, winter, spring" );
list2 := @Explode( "summer, winter, leaf" ); 
FIELD Exe := Exe; @SetField
("Exe";@Trim(@ReplaceSubstring( list1 ; list2 ; "" )) )

—Bala R.

******************************************

You can also replace @NewLine with @Char(10) throughout the entire formula. Otherwise, all the displays truncate after a single entry.

I don't know if this only occurs on our Lotus Notes installation, but I find that in column formula and @prompts @Char(10) works, whereas @Newline usually doesn't.
—Angelo M.

Do you have comments on this tip? Let us know.

Related information from SearchDomino.com:

  • FAQ: Formula advice
  • Tip: How to create a forgiving Notes/Domino date parser with Formula
  • Tip: Setting row colors by category in a Lotus Notes view
  • Learning Guide: Formula language
  • Reference Center: Formula language for Lotus Notes and Domino

    This tip was submitted to the SearchDomino.com tip library by member Peter Skold. Please let others know how useful it is via the rating scale below. Do you have a useful Lotus Notes, Domino, Workplace or WebSphere tip or code snippet to share? Submit it to our monthly tip contest and you could win a prize.

    This was first published in December 2006

  • There are Comments. Add yours.

     
    TIP: Want to include a code block in your comment? Use <pre> or <code> tags around the desired text. Ex: <code>insert code</code>

    REGISTER or login:

    Forgot Password?
    By submitting you agree to receive email from TechTarget and its partners. If you reside outside of the United States, you consent to having your personal data transferred to and processed in the United States. Privacy
    Sort by: OldestNewest

    Forgot Password?

    No problem! Submit your e-mail address below. We'll send you an email containing your password.

    Your password has been sent to:

    Disclaimer: Our Tips Exchange is a forum for you to share technical advice and expertise with your peers and to learn from other enterprise IT professionals. TechTarget provides the infrastructure to facilitate this sharing of information. However, we cannot guarantee the accuracy or validity of the material submitted. You agree that your use of the Ask The Expert services and your reliance on any questions, answers, information or other materials received through this Web site is at your own risk.