lib/csv.nit

   1 # This file is part of NIT ( http://www.nitlanguage.org ).
   2 #
   3 # Licensed under the Apache License, Version 2.0 (the "License");
   4 # you may not use this file except in compliance with the License.
   5 # You may obtain a copy of the License at
   6 #
   7 #     http://www.apache.org/licenses/LICENSE-2.0
   8 #
   9 # Unless required by applicable law or agreed to in writing, software
  10 # distributed under the License is distributed on an "AS IS" BASIS,
  11 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  12 # See the License for the specific language governing permissions and
  13 # limitations under the License.
  14
  15 # CSV output facilities
  16 module csv
  17
  18 # A CSV document representation
  19 class CSVDocument
  20         private var file: String
  21         private var header: Array[String] = new Array[String]
  22         private var lines: Array[Array[String]] = new Array[Array[String]]
  23
  24         init(file: String) do self.file = file
  25
  26         fun set_header(values: Object...) do
  27                 header.clear
  28                 for value in values do header.add(value.to_s)
  29         end
  30
  31         fun add_line(values: Object...) do
  32                 if values.length != header.length then
  33                         print "CSV error: header declares {header.length} columns, line contains {values.length} values"
  34                         abort
  35                 end
  36                 var line = new Array[String]
  37                 for value in values do line.add(value.to_s)
  38                 lines.add(line)
  39         end
  40
  41         redef fun to_s do
  42                 var str = header.join(";") + "\n"
  43                 for line in lines do str += line.join(";") + "\n"
  44                 return str
  45         end
  46
  47         fun save do
  48                 var out = new OFStream.open(self.file)
  49                 out.write(self.to_s)
  50                 out.close
  51         end
  52 end