gridtables

Parser for reStructuredText-style grid tables.

This package provides a parser for plain-text representations of tables, like the one given below.

+---------------------+-----------------------+
| Location            | Temperature 1961-1990 |
|                     | in degree Celsius     |
|                     +-------+-------+-------+
|                     | min   | mean  | max   |
+=====================+=======+=======+=======+
| Antarctica          | -89.2 | N/A   | 19.8  |
+---------------------+-------+-------+-------+
| Earth               | -89.2 | 14    | 56.7  |
+---------------------+-------+-------+-------+

Character widths

The tables are intended to look good when viewed in a monospace font. Therefore, wide and full-width characters, as those in East Asian scripts, are counted as two characters.

Column alignments

The parser re-implements a table extensions from John MacFarlane's pandoc, namely support for column-wide cell alignments. The alignment of cells is determined by placing colons in the row that separates the table head from the body, like so:

+------+--------+-------+
| left | center | right |
+:=====+:======:+======:+
| 1    | 2      | 3     |
+------+--------+-------+

The first line must be used for headless tables:

+:-----+:------:+------:+
| left | center | right |
+------+--------+-------+
| a 1  | b 2    | c 3   |
+------+--------+-------+

Algorithm

The cell tracing algorithm used in this package has been translated from the original Python implementation for reStructuredText. The parser has been placed in the public domain.

Usage

The usual way to use this package will be to use it as part of a parsec parser:

main :: IO ()
main = do
  let gt = T.unlines
           [ "+------+--------+-------+"
           , "| left | center | right |"
           , "+:=====+:======:+======:+"
           , "| 1    | 2      | 3     |"
           , "+------+--------+-------+"
           ]
  in print (runParser GT.gridTable () "table" gt)

Use traceLines :: [Text] -> Maybe (GridTable [Text]), if the table's raw lines have been retrieved in a different way.