Parsing a CSV-format data file

• opening and closing a file
• using 'trim', 'readtextline', 'nextfield'
• using 'parseint', 'parsereal', 'parsetext', 'parseextn'
• using loops: while

(!*******************************************************
  * Mosel Example Problems                              *
  * ======================                              *
  *                                                     *
  * file readcsv.mos                                    *
  * ````````````````                                    *
  * Example for the use of the Mosel language           *
  * (Read a data file in CSV format)                    *
  *                                                     *
  * (c) 2014 Fair Isaac Corporation                     *
  *     author: Y. Colombani                            *
  *******************************************************!)

model readcsv

uses 'mmsystem'

declarations
 public example_file=`
1|Estaque|1/2/1980|13.2
2|Endoume|23/5/2001|-77.3
23|wrongly formatted line
3|Lodi|12/12/1999|1
`
 l:text
 ndx:integer
 word:text
 when:date
 number:real
end-declarations

fopen("text:example_file",F_INPUT)
setparam("sys_sepchar",getchar("|",1))     ! field separator
setparam("datefmt","%d/%m/%y")             ! date format
while (readtextline(l)>0) do
 trim(l,SYS_RIGHT)                         ! remove end of line character
 setparam("sys_endparse",0)                ! start parsing
 b:=nextfield(l)                           ! jump to first field
 ndx:=parseint(l); b:=b and nextfield(l)   ! parse an integer,
 word:=parsetext(l); b:=b and nextfield(l) ! some text,
 parseextn(l,when); b:=b and nextfield(l)  ! a date,
 number:=parsereal(l)                      ! and a number
 
 if not b then
  writeln("!! Line not properly formatted")
 else
  writeln("->",ndx,"\t",word,"\t",when,"\t",number)
 end-if
end-do
end-model