sv

sv

For all your separated value needs.

• sv.Stringifier is a Readable stream.
• sv.Parser is a Writable stream.

Install

npm install sv

The optimist dependency is only required for command line use.

API usage

All tabular data must / will have column names on the first row.

Parsing

sprints.csv:

index	name	time
1	chris	1:18
2	daniel	1:17
3	lewis	1:30
4	stephen	1:16
5	larry	1:32

And in node:

var sv = require('sv');
var parser = new sv.Parser();
parser.on('data', function(obj) {
  console.log('sprinter ->', obj);
});

var fs = require('fs');
var sprints = fs.createReadStream('sprints.csv', {encoding: 'utf8'});
sprints.pipe(parser);

Stringifying

var expenses = [
  {name: 'Tip'                },
  {name: 'Lunch', amount: 5.90},
  {name: 'Latte', amount: 3.15},
  {name: 'Paper', amount: 2.10},
  {name: 'Pens' , amount: 4.59},
  {               amount: 9.16}
];

var sv = require('sv');
var stringifier = new sv.Stringifier({peek: 2, missing: 'n/a'});
stringifier.pipe(process.stdout);
expenses.forEach(function(expense) {
  stringifier.write(expense);
});

// if you write set 'peek' to more rows than you have in your data,
// you'll need to call stringifier end so that they get flushed.
stringifier.end();

• N.b.: If you pipe a buffer or (i.e., with a stringifier) into a parser, the parser will not receive any encoding. You must set the encoding on the parser in those cases.

Stringifier features:

1. Infer column names from a list of objects.
2. Convert from objects to csv / tsv plaintext.
   • Also allows writing arrays / strings directly.
3. Write header automatically.

Parser features:

1. Infer delimiter from input.
2. Infer column names from first line of input.
3. Handle universal newlines (\r, \r\n, or \n).

CLI usage

shopt -s globstar
for csv in ~/corpora/testsheets/**/*.csv; do
  echo
  file "$csv"
  echo "Tunneling through multiple 'sv' calls should be transparent."
  cat "$csv" | sv -j | wc -l
  cat "$csv" | sv | sv -j | wc -l
done

TODO

• Decide how to encode a field like {id: 1, name: '"chris'}, when the delimiter is , and quotechar is ".
  • This is weird because it doesn't need quoting, but without, the quotechar marker will trigger an inside state, but there's no end quote.)

Also see the notes for more development comments.

License

Copyright © 2013 Christopher Brown. MIT Licensed.