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https://github.com/lovasko/comma
CSV Parser & Producer
https://github.com/lovasko/comma
csv haskell parsing rfc-4180 text
Last synced: 10 days ago
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CSV Parser & Producer
- Host: GitHub
- URL: https://github.com/lovasko/comma
- Owner: lovasko
- License: bsd-2-clause
- Created: 2017-01-12T11:23:32.000Z (almost 8 years ago)
- Default Branch: master
- Last Pushed: 2017-02-07T17:14:01.000Z (almost 8 years ago)
- Last Synced: 2024-04-24T13:44:45.075Z (8 months ago)
- Topics: csv, haskell, parsing, rfc-4180, text
- Language: Haskell
- Homepage:
- Size: 10.7 KB
- Stars: 0
- Watchers: 2
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE
Awesome Lists containing this project
README
# Text.Comma
[](https://travis-ci.org/lovasko/comma)
The `comma` package implements parsing and producing of the CSV format.
## Build & install
There are two standard ways of obtaining the module:
* by cloning the git repository: `git clone https://github.com/lovasko/comma`
* by using the central Hackage server: `cabal install comma`
### Dependencies
Main part, the library itself, depends on two packages:
* `attoparsec`
* `text`
In addition, the testing component of the project depends on the `QuickCheck`
package.
## API
The `Text.Comma` module exports only two functions: `comma` and `uncomma`,
parsing and producing CSV respectively. The function prototypes are as follows:
```haskell
-- | Parse a block of text into a CSV table.
comma :: T.Text -- ^ CSV text
-> Either String [[T.Text]] -- ^ error | table
```
```haskell
-- | Render a table of texts into a valid CSV output.
uncomma :: [[T.Text]] -- ^ table
-> T.Text -- ^ CSV text
```
### Example
The following example loads any CSV file and prepends a column that contains
row numbers:
```haskell
{-# LANGUAGE OverloadedStrings #-}
import Text.Comma
import System.Exit
import qualified Data.Text as T
import qualified Data.Text.IO as T
-- | Prepend a number in front of each row.
number :: [[T.Text]] -> [[T.Text]]
number = zipWith (:) (map (T.pack . show) [0..])
main :: IO ()
main = T.readFile "table.csv" >>= (\file -> case comma file of
Left err -> T.putStrLn ("ERROR: " <> T.pack err) >> exitFailure
Right csv -> T.writeFile "table.csv" (uncomma $ number csv) >> exitSuccess)
```
Example usage:
```bash
$ cat table.csv
name,surname,language
Dennis,Ritchie,C
Larry,Wall,Perl
John,McCarthy,Lisp
$ ./number && cat table.csv
0,name,surname,language
1,Dennis,Ritchie,C
2,Larry,Wall,Perl
3,John,McCarthy,Lisp
```
## Standards
Both producing and parsing of CSV files closely follows the
[RFC4180](https://tools.ietf.org/html/rfc4180) document. The `comma`
implementation has made the following decisions:
* record separator is always only `\n` ('\r` is not recognized as a newline
symbol)
* it is not required for the last record to be trailed with a `\n`. This
means that `comma "hello\nworld" == comma "hello\nworld\n" == Right
[["hello"], ["world"]]`
## License
The `comma` package is licensed under the terms of the [2-clause BSD
license](LICENSE). In case you need any other license, feel free to contact the
author.
## Author
Daniel Lovasko