# Deprecated alias for `write_to_file`.
fun save(file: String) do write_to_file(file)
+
+ # Load from the specified stream.
+ #
+ # Parameters:
+ #
+ # * `stream`: Input stream.
+ # * `has_header`: Is the first row the header?
+ # * `skip_empty`: Do we skip the empty lines?
+ # For details, see `CsvReader.skip_empty`.
+ fun load_from(stream: IStream, has_header: Bool, skip_empty: Bool) do
+ var reader = new CsvReader.with_format(stream, format)
+ reader.skip_empty = skip_empty
+ if has_header then
+ if reader.is_ok then
+ header = reader.item
+ else
+ header.clear
+ end
+ end
+ records.clear
+ for record in reader do records.add(record)
+ end
+
+ # Load from the specified file.
+ #
+ # Parameters:
+ #
+ # * `path`: Path of the file.
+ # * `has_header`: Is the first row the header?
+ # * `skip_empty`: Do we skip the empty lines?
+ fun load(path: String, has_header: Bool, skip_empty: Bool) do
+ var istream = new IFStream.open(path)
+ load_from(istream, has_header, skip_empty)
+ istream.close
+ end
end
# Appends CSV rows to a file.
end
end
-# The CSV format recommended by RFC 4180.
+# Reads rows from a CSV file.
+#
+# By default, uses the format recommended by RFC 4180 (see `rfc4180`).
+#
+# ~~~nit
+# var example = new StringIStream("""
+# foo,bar\r
+# "Hello, word!",1234.5 + 42\r
+# "Something\r
+# ""else""\", baz\r
+# """)
+# var reader = new CsvReader(example)
+# var table = new Array[Array[String]]
+#
+# for row in reader do table.add row
+# assert table == [
+# ["foo","bar"],
+# ["Hello, word!","1234.5 + 42"],
+# ["Something\r\n\"else\""," baz"]
+# ]
+# ~~~
+class CsvReader
+ super Iterator[Array[String]]
+
+ # The input stream.
+ var istream: IStream
+
+ # The format to use.
+ #
+ # Defaults to `rfc4180`.
+ var format: CsvFormat = rfc4180 is lazy
+
+ # Do we skip the empty lines?
+ #
+ # Note: Even if this attribute is `false`, the presence of an line ending at
+ # end of the last row does not change the number of returned rows.
+ # This is because the line endings are processed as terminators, not as
+ # separators. Therefore, when there is more than one line ending at the end
+ # of the file, the additional lines are interpreted as empty rows that
+ # are skipped only if `skip_empty` is set to `true`.
+ #
+ # `false` by default.
+ var skip_empty: Bool = false is writable
+
+ # The last read row.
+ private var row: nullable Array[String] = null
+
+ # Did we read something?
+ private var started = false
+
+ # Create a new reader with the specified format.
+ init with_format(istream:IStream, format: CsvFormat) do
+ self.istream = istream
+ self.format = format
+ end
+
+ # Read the first row, if needed.
+ fun prepare do
+ if not started then
+ row = read_row
+ started = true
+ end
+ end
+
+ redef fun next do
+ prepare
+ assert is_ok else
+ sys.stderr.write "Already at the end of the stream.\n"
+ end
+ row = read_row
+ end
+
+ # Return the last read row.
+ redef fun item do
+ prepare
+ return row.as(not null)
+ end
+
+ redef fun is_ok do
+ prepare
+ return row != null
+ end
+
+ # Free some internal ressources and set `is_ok` to `false`.
+ #
+ # Do not close the input stream.
+ redef fun finish do row = null
+
+ # Close the input stream.
+ fun close do istream.close
+
+ private fun read_row: nullable Array[String] do
+ if istream.eof then return null
+ var row = new Array[String]
+ var value = new RopeBuffer
+
+ # Number of unescaped characters since the last delimiter or separator.
+ var unescaped = 0
+
+ # Do we read the start of a row?
+ var got_row = false
+
+ # Do we found a delimited string in the current cell?
+ var got_delimiter = false
+
+ loop
+ var i = istream.read_char
+ var c: Char
+
+ if i < 0 then
+ if got_row then
+ row.add value.to_s
+ return row
+ else
+ return null
+ end
+ end
+ c = i.ascii
+
+ if c == format.delimiter then
+ if got_delimiter and unescaped == 0 then
+ # Got an escaped delimiter.
+ value.add format.delimiter
+ end
+ # Read all bytes until the delimiter.
+ loop
+ i = istream.read_char
+ assert not_eof: i >= 0 else
+ sys.stderr.write "Unexpected end of file before the end of a delimited value.\n"
+ end
+ c = i.ascii
+ if c == format.delimiter then break
+ value.add c
+ end
+ unescaped = 0
+ got_row = true
+ got_delimiter = true
+ else if c == format.separator then
+ # Flush the value to the row.
+ row.add value.to_s
+ value.clear
+ unescaped = 0
+ got_delimiter = false
+ else
+ value.add c
+ unescaped += 1
+ if unescaped >= format.eol.length and
+ value.has_suffix(format.eol) then
+ var value_trimed = value.substring(0,
+ value.length - format.eol.length).to_s
+ if skip_empty and row.is_empty and
+ value_trimed.is_empty and
+ not got_delimiter then
+ # Skip the empty line.
+ value.clear
+ unescaped = 0
+ got_row = false
+ else
+ row.add value_trimed
+ return row
+ end
+ else
+ got_row = true
+ end
+ end
+ end
+ end
+end
+
+# The CSV format recommended by [RFC 4180](https://tools.ietf.org/html/rfc4180).
#
# * `delimiter`: `'"'`
# * `separator`: `','`
nitlanguage / nit.git / blobdiff