Mine is Better Than mline()

mline() is a bit nasty.  If the last word in a line ends right at
the line length, the following space will be at the start of the next
line.

     Consider the string
          "This is a contrived example, but then, aren't they all?"
with a width of 19.  mline() breaks it up into
          "This is a contrived"
          " example, but then,"
          " aren't they all?"
My routine does it right:
          "This is a contrived"
          "example, but then,"
          "aren't they all?"

     Here is the code:

***** Start of Included Code *****
* mtolines
* Convert a Memo Value to Lines of Specified Length
* Last Modification: 2007-04-18
*
* This function is necessary, because the way the mline() splits up
memos can
* result in blanks at the start of a mid-paragraph line.

procedure mtolines
lparameters;
 physlines,;  && C: 1-D array by reference: returns the lines.  It
will be
 ;            &&    dimensioned to the number of lines, but if memo is
empty,
 ;            &&    one blank line will returned.  Leading and
trailing empty
 ;            &&    lines will be suppressed.
 thememo,;    && M/C: the memo (or string) to convert
 linewidth,;  && N: the line width to use
 maxlines,;   && N: the maximum number of lines to return.  (This must
be at
 ;            &&    least 1.)  If there is still more memo, put "..."
at the
 ;            &&    end of the last line.  The "..." may overwrite
characters
 ;            &&    so that it will fit in linewidth characters.
 fpad         && L: whether to pad the end of each line with spaces.
This is
 ;            &&    done before the "..." is placed.
*
* Returns the number of lines.  This is the same as alen(physlines).

   local rawlines(1)     && holds the unbroken-up lines (paragraphs)
   local crawlines       && size of rawlines()

   crawlines=alines(rawlines,thememo,0)     && 3rd: do not trim

   local cretlines     && numbers of lines returned, but 0 if empty
memo

   * Determine start of non-empty lines.
   local startline
   startline=1
   do while startline<=crawlines and empty(rawlines(startline))
      startline=startline+1
      enddo

   * Determine end of non-empty lines.
   local endline
   endline=crawlines
   do while endline>=startline and empty(rawlines(endline))
      endline=endline-1
      enddo

   * If memo is all empty lines, simple exit.
   if endline<startline
      dimension thearray(1)
      if fpad
         thearray(1)=space(linewidth)
      else
         thearray(1)=""
         endif
      return 0
      endif

   * Parse each raw line.
   * Trailing spaces will be trimmed.  Leading spaces will not be
trimmed.
   * Breaks will usually occur at spaces, rag right, and the following
   * physical line will not have leading spaces.  If a word is too
long to
   * fit on one line, it will be hyphenated (at the last position) and
   * continued on the next physical line.

   local cphyslines
   cphyslines=0

   local i, currraw, rawlinelen, physstart, lineend, currchar,
gotspace

   i=startline
   do while i<=endline and cphyslines<=maxlines+1
   && The second conjunct catches the situation of too many lines. The
   && condition is not caught right away, but only after at least one
too
   && many lines has been parsed (ensuring that there really are too
many)
   && and an entire paragraph has been finished (so it might be more
than one
   && too many lines).

      currraw=rtrim(rawlines(i))
      rawlinelen=len(currraw)

      if empty(currraw)     && empty raw line
         cphyslines=cphyslines+1
         dimension physlines(cphyslines)
         physlines(cphyslines)=""

      else     && raw line not empty
         physstart=1
         do while physstart<=rawlinelen
            lineend=physstart+linewidth-1
            if lineend>rawlinelen     && last fragment
               cphyslines=cphyslines+1
               dimension physlines(cphyslines)
               physlines(cphyslines)=substr(currraw,physstart)
               physstart=rawlinelen+1
            else     && a full physical line
               currchar=lineend
               gotspace=.f.
               if rawlinelen>lineend and
substr(currraw,currchar+1,1)=" "
               && Handle case of next char after segment is a space.
                  gotspace=.t.
                  currchar=currchar+1
                  endif
               do while currchar>=physstart and not gotspace
                  if substr(currraw,currchar,1)=" "
                     gotspace=.t.
                  else
                     currchar=currchar-1
                     endif
                  enddo
               if gotspace
                  cphyslines=cphyslines+1
                  dimension physlines(cphyslines)
                  physlines(cphyslines)=;
 rtrim(substr(currraw,physstart,currchar-physstart+1))
                  physstart=currchar
               else
                  cphyslines=cphyslines+1
                  dimension physlines(cphyslines)
                  physlines(cphyslines)=;
                   substr(currraw,physstart,linewidth-1)+"-"
                  physstart=lineend
                  endif
               do while;
                physstart<=rawlinelen and
substr(currraw,physstart,1)=" "
                  physstart=physstart+1
                  enddo
               endif
            enddo
         endif

      i=i+1
      enddo

   *

   * Pad if desired.
   if fpad
      for i=1 to cphyslines
         physlines(i)=padr(physlines(i),linewidth)
         endfor
      endif

   * Add "..." if memo continues.
   if cphyslines>maxlines
      cphyslines=maxlines
      dimension physlines(cphyslines)
 physlines(cphyslines)=left(physlines(cphyslines),linewidth-3)+"..."
      endif

   *

   return cphyslines

   endproc
***** End of Included Code *****

Sincerely,

Gene Wirchenko

Computerese Irregular Verb Conjugation:
     I have preferences.
     You have biases.
     He/She has prejudices.