Simple CSV Parser

This is a CSV (delimiter can be changed) parser with a focus on:

1. Simplicity
2. Robustness
3. Performance (to a lesser extent)

It follows RFC 4180, but allows for non-conformant files to be processed. In order to accomplish this, it makes the following assumptions:

1. Commas on the end of a line results in a empty string for that column. * 1,2,3, is parsed as ["1","2","3",""]
2. Double quotes in a field that is not enclosed in double quotes are processed as a regular character and are included in the column string. * 1,2",3 is parsed as ["1","2\"","3"]
3. Non-delimiter characters immediately following a quoted field are treated as part of the column data and are appended to the column string. * 1,2,"3"123 is parsed as ["1","2","3123"]
4. An EOF in the middle of a quoted field is parsed as if the field was properly closed. * 1,2,"3*EOF* is parsed as ["1","2","3"]
5. There is no error for empty lines or varying number of columns per line. * An empty line is parsed as []

Limitations

• Lines are assumed to be UTF8 and are decoded "lossily" via Rust's String::from_utf8_lossy function.
• The iterator implementation forces an allocation for every row.

Usage

Add to your Cargo.toml:

[dependencies]
simple_csv = "~0.0.2"

Simple CSV usage

let test_string = "1,2,3\r\n4,5,6".to_string();
let bytes = test_string.into_bytes();
let mut test_csv_reader = bytes.as_slice();

let mut parser = SimpleCsv::new(&mut test_csv_reader);

assert_eq!(parser.next_row(), Ok(vec!["1".to_string(),"2".to_string(),"3".to_string()].as_slice()));
assert_eq!(parser.next_row(), Ok(vec!["4".to_string(),"5".to_string(),"6".to_string()].as_slice()));
assert!(parser.next_row().is_err());

Different Delimiter

let test_string = "1|2|3\r\n4|5|6".to_string();
let bytes = test_string.into_bytes();
let mut test_csv_reader = bytes.as_slice();

let mut parser = SimpleCsv::with_delimiter(&mut test_csv_reader,'|');

assert_eq!(parser.next_row(), Ok(vec!["1".to_string(),"2".to_string(),"3".to_string()].as_slice()));
assert_eq!(parser.next_row(), Ok(vec!["4".to_string(),"5".to_string(),"6".to_string()].as_slice()));
assert!(parser.next_row().is_err());

Using a iterator

let test_string = "1|2|3\r\n4|5|6".to_string();
let bytes = test_string.into_bytes();
let mut test_csv_reader = bytes.as_slice();

let mut parser = SimpleCsv::with_delimiter(&mut test_csv_reader,'|');

for row in parser {
	println!("{}",row);
}

To Do

• Improve malformed UTF8 handling
• Implement CSV writer?
• Allow the iterator method to return errors somehow?