'String.Format
'Emulates the AML [format] function for generating formatted text

'Arguments:

'<format_string> - the string to be formatted.  Special format variables,
'%1% to %n%, can be placed within the format string to indicate where
'arguments should be substituted.  A field width for each argument can
'also be specified by including a comma and the field width after the
'format variable number (e.g., %1,5%).  Negative field widths cause
'output text to be right justified.

'{argument1...argument_n} - the arguments to be substituted into the
'format string.  These must be strings.  Arguments are substituted into
'the format string with the order of the arguments corresponding to the
'order of the format variables in the format string.

'Example:

'format_string = " AREA : %1,14%(%2%)  %3,-8%A"
'temp1 = "COOPER"
'temp2 = "0057"
'temp3 = 999
'temp3.SetFormat("d.dd")
'output = av.Run("String.Format", {format_string,temp1,temp2,temp3.AsString})

'output will equal " AREA : COOPER        (0057)    999.00A"

FS = SELF.Get(0)
i = 1
output = ""
while (i <= FS.Count)
   char = FS.Middle(i - 1, 1)
   if (char = "%") then
      j = i + 1
      statement = ""
      subst = ""
      notdone = TRUE
      while (notdone)
         char = FS.Middle(j - 1, 1)
         if (char = "%") then
            comma = statement.IndexOf(",")
            if (comma > 0) then
               varnum = statement.AsTokens(",").Get(0).AsNumber
               strwid = statement.AsTokens(",").Get(1).AsNumber
               if (strwid < 0) then
                  strwid = strwid.Abs
                  just = "R"
               else
                  just = "L"
               end
               vartxt = SELF.Get(varnum)
               varwid = vartxt.Count
               if (varwid > strwid) then
                  subst = String.MakeBuffer(strwid).Translate(" ","*")
               else
                  buff = strwid - varwid
                  if (buff = 0) then
                     subst = vartxt
                  else
                     if (just = "L") then
                        subst = vartxt+String.MakeBuffer(buff)
                     else
                        subst = String.MakeBuffer(buff)+vartxt
                     end
                  end
               end
            else
               subst=SELF.Get(statement.AsNumber)
            end
            notdone = FALSE
         else
            statement = statement+char
            j = j + 1
            if (j > FS.Count) then
               notdone = FALSE
            end
         end
      end
      output = output+subst
      if (j <= FS.Count) then
        i = j
      end
   else
      output = output+char
   end
   i = i + 1
end

return output