lib/csv/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         super Streamable
  21
  22         var header: Array[String] = new Array[String] is writable
  23         var records: Array[Array[String]] = new Array[Array[String]]
  24
  25         fun set_header(values: Object...) do
  26                 header.clear
  27                 for value in values do header.add(value.to_s)
  28         end
  29
  30         fun add_record(values: Object...) do
  31                 assert values.length == header.length else
  32                         sys.stderr.write "CSV error: Header declares {header.length} columns, record contains {values.length} values.\n"
  33                 end
  34                 var record = new Array[String]
  35                 for value in values do record.add(value.to_s)
  36                 records.add(record)
  37         end
  38
  39         private fun write_line_to(line: Collection[String], stream: OStream)
  40         do
  41                 var i = line.iterator
  42                 if i.is_ok then
  43                         stream.write(i.item)
  44                         i.next
  45                         while i.is_ok do
  46                                 stream.write(";")
  47                                 stream.write(i.item)
  48                                 i.next
  49                         end
  50                 end
  51                 stream.write("\n")
  52         end
  53
  54         redef fun write_to(stream) do
  55                 write_line_to(header, stream)
  56                 for record in records do write_line_to(record, stream)
  57         end
  58
  59         # Deprecated alias for `write_to_file`.
  60         fun save(file: String) do write_to_file(file)
  61 end