Text.RowRecord

Convert lists of strings to records.

Tables

type Column = String

Identifies a column.

type Row = Map Column String

A row of String data.

type Table = [Row]

A table.

fromStrings :: [[String]] -> Result Table

Convert a list of String rows into a Table. Uses the first row as column names.

Parsing fields

data Result a

A parse result.

Constructors

Success a

Failure RowError

Instances

Monad Result

Functor Result

Applicative Result

Show a => Show (Result a)

data RowError

Possible errors from parsing a row.

Constructors

MissingField Column

NoParse Column String

Instances

Show RowError

class Field a where

Class of field types which can be decoded from String.

The input can be Nothing to represent a missing field. The instance Field a => Field (Maybe a) models optional fields.

If your record contains custom types, you must create a Field instance for each. If you have base types but need different parsing behavior, you can use a newtype wrapper.

Methods

decode :: Maybe String -> Result a

Instances

Field Bool

Field Char

Field Double

Field Float

Field Int

Field Integer

Field String

Field a => Field (Maybe a)

require :: (String -> Maybe a) -> Maybe String -> Result a

Implement decode for a required field.

safeRead :: Read a => String -> Maybe a

read in Maybe.

getField :: Field a => Column -> Row -> Result a

Decode a field by column name.

Called from TH-generated code, but may be useful independently.

Parsing tables

class ParseRow a where

Class of types which can be parsed from a Row. These types are typically single-constructor records.

Instances may be generated using Text.RowRecord.TH.

Methods

parseRow :: Row -> Result a

parseTable :: ParseRow a => Table -> Result [a]

Parse a whole table.