Initial project import

tools/v/vlib/encoding/csv/writer.v

@@ -0,0 +1,90 @@
+// Copyright (c) 2019-2024 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 {
+	use_crlf  bool
+	delimiter u8
+mut:
+	sb strings.Builder
+}
+
+@[params]
+pub struct WriterConfig {
+pub:
+	use_crlf  bool
+	delimiter u8 = `,`
+}
+
+// new_writer returns a reference to a Writer
+pub fn new_writer(config WriterConfig) &Writer {
+	return &Writer{
+		sb:        strings.new_builder(200)
+		use_crlf:  config.use_crlf
+		delimiter: config.delimiter
+	}
+}
+
+// write writes a single record
+pub fn (mut w Writer) write(record []string) !bool {
+	if !valid_delim(w.delimiter) {
+		return &InvalidDelimiterError{}
+	}
+	le := if w.use_crlf { '\r\n' } else { '\n' }
+	for n, field_ in record {
+		mut field := field_
+		if n > 0 {
+			w.sb.write_string(w.delimiter.ascii_str())
+		}
+		if !w.field_needs_quotes(field) {
+			w.sb.write_string(field)
+			continue
+		}
+		w.sb.write_string('"')
+		for field.len > 0 {
+			mut i := field.index_any('"\r\n')
+			if i < 0 {
+				i = field.len
+			}
+			w.sb.write_string(field[..i])
+			field = field[i..]
+			if field.len > 0 {
+				z := field[0]
+				match z {
+					`"` { w.sb.write_string('""') }
+					`\r`, `\n` { w.sb.write_string(le) }
+					else {}
+				}
+
+				field = field[1..]
+			}
+		}
+		w.sb.write_string('"')
+	}
+	w.sb.write_string(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.ascii_str()) || field.index_any('"\r\n') != -1 {
+		return true
+	}
+	return false
+}
+
+// str returns the writer contents
+pub fn (mut w Writer) str() string {
+	return w.sb.str()
+}