The next lexical functions are F$EDIT and F$ELEMENT. The F$EDIT function is described here and F$ELEMENT in the second half of the article.

Value

Meaning

COLLAPSE

Remove all spaces and tabs.

COMPRESS

Replace multiple spaces or tabs with a single space

LOWERCASE

Change all uppercase characters to lowercase

TRIM

Remove leading and trailing spaces and tabs

UNCOMMENT

Remove comments

UPCASE

Change all lowercase characters to uppercase

Example
$ X = F$EDIT(" Hello world ! This is a comment","LOWERCASE,TRIM,UNCOMMENT")

This would return a value equal to "hello world". Note that the comment was removed, the uppercase "H" was changed to lowercase, and the leading and trailing spaces were removed.

        Function_Edit : begin
                            if( Missing_Parentheses( '(' ) ) then
                            begin
                                exit ;
                            end ;
                            if( Parse_Edit( Err, Context ) ) then
                            begin
                                exit ;
                            end ;
                            if( Missing_Parentheses( ')' ) ) then
                            begin
                                exit ;
                            end ;
                            S := Context ;
                        end ;

function Parse_Edit( var Err : integer ; var Context : string ) : boolean ;

var I : integer ;
    In_Quote : boolean ;
    Loop : integer ;
    S, S1 : string ;

begin
    Result := True ; // Assume error
    S := Get_Parameter( Err, Context ) ;
    if( Err <> 0 ) then
    begin
        exit ;
    end ;
    if( Get_Token <> ',' ) then
    begin
        Err := UCL_ARGREQ ;
        exit ;
    end ;
    S1 := Edit( Get_Parameter( Err, Context ), -1, 0 ) ;
    if( Err <> 0 ) then
    begin
        exit ;
    end ;
    I := Parse_Edit_Options( S1, Context ) ;
    if( I = 0 ) then
    begin
        Err := UCL_IVKEYW ;
        exit ;
    end ;

    if( ( I and 32768 ) <> 0 ) then // Remove comments
    begin
        In_Quote := False ;
        for Loop := 1 to length( S ) do
        begin
            if( S[ Loop ] = '"' ) then
            begin
                In_Quote := not In_Quote ;
            end else
            if( ( S[ Loop ] = '!' ) and ( not In_Quote ) ) then
            begin
                setlength( S, Loop - 1 ) ;
                break ;
            end ;
        end ; // for Loop := 1 to length( S )
    end ; // if( ( I and 32768 ) <> 0 )
    I := I and 32767 ;
    Context := Edit( S, I or 256, 0 ) ;
    Result := False ; // No error
end ; // Parse_Edit

function Parse_Edit_Options( S : string ; var Context : string ) : integer ;

var I : integer ;
    S1 : string ;

begin
    Result := 0 ;
    while( S <> '' ) do
    begin
        I := pos( ',', S + ',' ) ;
        S1 := copy( S, 1, I - 1 ) ;
        S := copy( S, I + 1, length( S ) ) ;
        if( S1 = 'COLLAPSE' ) then // Removes all spaces or tabs.
        begin
            Result := Result or 2 ;
        end else
        if( S1 = 'COMPRESS' ) then // Replaces multiple spaces or tabs with a single space.
        begin
            Result := Result or 16 ;
        end else
        if( S1 = 'LOWERCASE' ) then // Changes all uppercase characters to lowercase.
        begin
            Result := Result or 512 ;
        end else
        if( S1 = 'TRIM' ) then // Removes leading and trailing spaces or tabs.
        begin
            Result := Result or 8 or 128 ;
        end else
        if( S1 = 'UNCOMMENT' ) then // Removes comments.
        begin
            Result := Result or 32768 ;
        end else
        if( S1 = 'UPCASE' ) then // Change all lowercase characters to uppercase.
        begin
            Result := Result or 32 ;
        end else
        begin
            Result := 0 ;
            Context := S1 ;
            exit ;
        end ;
    end ;
    if( ( Result and 544 ) = 544 ) then // Both UPCASE and LOWERCASE
    begin
        Result := Result and ( not 512 ) ; // Remove lowercase option
    end ;
end ; // Parse_Edit_Options

Example
$ X = F$ELEMENT(1,",","A,B,C,D,E,F,G,H,I,J")
This would return a value equal to "B".

        Function_Element : begin
                               if( Missing_Parentheses( '(' ) ) then
                               begin
                                   exit ;
                               end ;
                               if( Parse_Element( Err, Context ) ) then
                               begin
                                   exit ;
                               end ;
                               if( Missing_Parentheses( ')' ) ) then
                               begin
                                   exit ;
                               end ;
                               S := Context ;
                           end ;

function Parse_Element( var Err : integer ; var Context : string ) : boolean ;

var Index, P, Start : int64 ;
    S, S1 : string ;

begin
    Result := True ; // Assume error
    S := Get_Parameter( Err, Context ) ;
    if( Err <> 0 ) then
    begin
        exit ;
    end ;
    Result := Missing_Comma( Err ) ;
    if( Result ) then
    begin
        exit ;
    end ;
    if( S <> '' ) then
    begin
        S := UCL_Strtoint( S ) ;
        if( not trystrtoint64( S, Index ) ) then
        begin
            Err := UCL_EXPSYN ; // Invalid expression syntax
            Context := S ;
            exit ;
        end ;
    end ;
    if( Index < 0 ) then
    begin
        Err := UCL_INVRANGE ;
        Context := S ;
        exit ;
    end ;

    S := Get_Parameter( Err, Context ) ;
    if( Err <> 0 ) then
    begin
        exit ;
    end ;
    if( length( S ) <> 1 ) then
    begin
        Err := UCL_STRTOOLNG ;
        Context := S ;
        exit ;
    end ;
    Result := Missing_Comma( Err ) ;
    if( Result ) then
    begin
        exit ;
    end ;

    S1 := Get_Parameter( Err, Context ) ;
    if( Err <> 0 ) then
    begin
        exit ;
    end ;

    if( S1 <> '' ) then
    begin
        Start := 1 ;
        P := 1 ;
        while( P <= length( S1 ) ) do
        begin
            if( S1[ P ] = S ) then
            begin
                if( Index = 0 ) then
                begin
                    break ;
                end ;
                Start := P + 1 ;
                dec( Index ) ;
            end ; // if( S1[ P ] = S )
            inc( P ) ;
        end ; // while( P < length( S1 ) )
        S1 := copy( S1, Start, P - Start ) ;
    end ; // if( S1 <> '' )
    if( Index > 0 ) then // Index is out of range
    begin
        S1 := S ;
    end ;

    Context := S1 ;
    Result := False ; // No error
end ; // Parse_Element