v/vlib/encoding/csv/writer.v

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// Copyright (c) 2019 Alexander Medvednikov. All rights reserved.
// Use of this source code is governed by an MIT license
// that can be found in the LICENSE file.
module csv
import strings
struct Writer {
sb strings.Builder
pub:
mut:
use_crlf bool
delimiter byte
}
pub fn new_writer() &Writer {
return &Writer{
delimiter: `,`,
sb: strings.new_builder(200)
}
}
// write writes a single record
pub fn (w mut Writer) write(record []string) ?bool {
if !valid_delim(w.delimiter) {
return err_invalid_delim
}
le := if w.use_crlf { '\r\n' } else { '\n' }
for n, _field in record {
mut field := _field
if n > 0 {
w.sb.write(w.delimiter.str())
}
if !w.field_needs_quotes(field) {
w.sb.write(field)
continue
}
w.sb.write('"')
for field.len > 0 {
mut i := field.index_any('"\r\n')
if i < 0 {
i = field.len
}
w.sb.write(field[..i])
field = field[i..]
if field.len > 0 {
z := field[0]
switch z {
case `"`:
w.sb.write('""')
case `\r` || `\n`:
w.sb.write(le)
}
field = field[1..]
}
}
w.sb.write('"')
}
w.sb.write(le)
return true
}
// Once we have multi dimensional array
// pub fn (w &Writer) write_all(records [][]string) {
// for _, record in records {
// w.write(record)
// }
// }
fn (w &Writer) field_needs_quotes(field string) bool {
if field == '' {
return false
}
if field.contains(w.delimiter.str()) || (field.index_any('"\r\n') != -1) {
return true
}
return false
}
pub fn (w &Writer) str() string {
return w.sb.str()
}