Text Parser - Printable Version

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FUNCTION ParseText$ (TextIn AS STRING, MaxWidth AS INTEGER, Action AS INTEGER) STATIC



    '-> Modifications added suggested by Pete 10/03/22. Corrects issue of crashing and mishandling of text

    '   in certain situations. (additions remarked in code below)

    '   - Function exit if text sent in is null

    '   - Handles non-breaking strings larger than space allocated

    '   - Handles end of text that has no trailing space

    '   - Clear text for next parsing event



    '-> Parses the string passed in into multiple lines of the maximum width desired

    '   The first time the function is called, regardless of action, the TextIn string is fully parsed

    '   Subsequent calls to the function with the same text will not parse the TextIn string again



    '-> INPUT PARAMETERS:

    '   TextIn   - the text string sent into the function

    '   MaxWidth - maximum width of text on a line

    '   Action   - 1 reports number of lines created, 0 returns lines of parsed text ("" = finished)



    '-> EXAMPLE:

    '   t$ = "The rain in Spain falls mainly on the plain. The weather in Spain seems pretty good!"

    '   Lines = VAL(ParseText$(t$, 40, 1)) '          report number of lines the text was parsed into

    '   DO '                                          get all parsed lines of text

    '       TextLine$ = ParseText$(t$, 40, 0) '       return the next line of parsed text

    '       IF TextLine$ <> "" THEN PRINT TextLine$ ' could easily be saved to an array as well

    '   LOOP UNTIL TextLine$ = "" '                   ParseText$ returns null when all lines returned



    '-> There is no need to have ParseText$ report the number of lines needed. A simple counter could be

    '   placed within the DO...LOOP as well. The report for the number of lines the text was parsed into will

    '   be returned as a string and need converted to a value VAL() as seen in the 2nd line of the example.



    DIM PText AS STRING '    previous text that was sent in

    DIM Index AS INTEGER '   array index counter

    DIM Plen AS INTEGER '    parse string length

    DIM Char AS STRING * 1 ' character analyzer

    DIM Parse AS STRING '    parsed string

    DIM WText AS STRING '    working text string

    DIM Done AS INTEGER '    flag to indicate parsing finished



    IF MaxWidth <= 0 THEN ParseText$ = "": EXIT FUNCTION '        (Pete) leave if null text sent in

    IF PText <> TextIn THEN '                                            was a new text string sent in?

        PText = TextIn '                                                 yes, remember text that was sent in

        WText = TextIn '                                                 get text sent in to work with

        Index = 0 '                                                      reset index counter

        Done = 0 '                                                       reset finished flag

        REDIM Text(0) AS STRING '                                        reset text array

    END IF

    IF NOT Done THEN '                                                   has parsing already been performed?

        DO '                                                             no, begin array loop

            Index = Index + 1 '                                          increment index counter

            REDIM _PRESERVE Text(Index) AS STRING '                      increase size of array



            ' (Pete) Non-breaking string larger than space alloted checked below.



            IF LEN(WText) > MaxWidth AND INSTR(MID$(WText, 1, MaxWidth + 1), " ") = 0 THEN ' (Pete)

                Plen = MaxWidth '                                 (Pete)  set length to maximum size

                Parse = MID$(WText, 1, Plen) '                    (Pete)  get the maximum size string allowed

            ELSE

                IF MID$(WText, MaxWidth + 1, 1) <> " " THEN '     (Pete) text with no trailing space?

                    Plen = MaxWidth '                             (Pete) yes, set length to remaining text

                ELSE '                                                   no, there is a a trailing space

                    Plen = MaxWidth + 1 '       (+1 for trailing spaces) set length to include space

                END IF

                DO '                                                     begin parse loop

                    IF LEN(WText) <= Plen THEN '                         remaining text all that is left?

                        Parse = MID$(WText, 1, Plen) '                   yes, get remaining text

                        Done = -1 '                                      parsing is done

                    ELSE '                                               no, text still longer than max width

                        IF INSTR(MID$(WText, 1, Plen), " ") = 0 THEN '   space found in text? (Pete)

                            Plen = Plen + 1 '                     (Pete) no, increment length

                        ELSE

                            DO '                                         begin space search loop

                                Char = MID$(WText, Plen, 1) '            get last character

                                IF Char <> " " THEN Plen = Plen - 1 '    if not a space then move back one

                            LOOP UNTIL Char = " " '                      leave when space found

                            Parse = LEFT$(WText, Plen - 1) '             get parsed string without space at end

                        END IF

                    END IF

                LOOP UNTIL Char = " " OR Done '                          leave when space found or parsing done

            END IF

            Text(Index) = Parse '                                        save the parsed text

            IF NOT Done THEN WText = MID$(WText, Plen + 1, LEN(WText)) ' remove parsed text from string

        LOOP UNTIL Done '                                                leave when parsing done

        Index = 0 '                                                      reset index counter for reporting

    END IF

    IF Action = 1 THEN '                                                 report number of lines?

        ParseText$ = STR$(UBOUND(Text)) '                                yes, return number of lines as a string

    ELSE '                                                               no, report parsed lines found

        Index = Index + 1 '                                              increment index counter

        IF Index > UBOUND(Text) THEN '                                   have all lines been reported?

            ParseText$ = "" '                                            yes, report nothing remaining

            PText = "" '                                          (Pete) clear for next parsing event

        ELSE '                                                           no, parsed text remains

            ParseText$ = Text(Index) '                                   report next line of text

        END IF

    END IF



END FUNCTION