Text.I18n.Po

Internationalization support for Haskell. This module contains PO parser. PO files are assumed to be in UTF-8 encoding.

Plural forms are not yet implemented.

modules Text.I18n, Control.Monad.Trans, and function putStrLn and putStr from System.IO.UTF8 are exported for convenience.

 import Prelude hiding (putStr,putStrLn)

Type Declarations

newtype Msgid

Constructors

Msgid String

Instances

Eq Msgid

Ord Msgid

Show Msgid

type Msgstr = String

newtype Locale

Constructors

Locale String

Instances

Eq Locale

Ord Locale

Show Locale

type Context = String

type I18n a = ReaderT (Locale, L10n, Maybe Context) Identity a

The Internationalization monad built using monad transformers.

type L10n = Map Locale (Map (Maybe Context) (Map Msgid [Msgstr]))

The Localization structure.

PO parsing

getL10n

Arguments

:: FilePath

Directory containing PO files.

-> IO (L10n, [ParseError])

Localization structure and a list of parse errors.

Builds L10n structure by parsing .po files contained in a given directory. L10n structure is to be passed to localize function. L10n structure is used internaly by the I18n monad.

I18n Monad Functions

localize

Arguments

:: L10n

Structure containing localization data

-> Locale

Locale to use

-> I18n a

Inernationalized expression

-> a

Localized expression

The top level localization function.

 import Text.I18n.Po
 import Prelude hiding (putStr,putStrLn)

 main = do
     (l10n,errors) <- getL10n "dir/to/po" -- directory containing PO files
     putStrLn $ localize l10n (Locale "en") (example "Joe")

gettext :: PrintfType a => String -> I18n a

The heart of I18n monad. Based on Text.Printf.printf.

 example :: String -> I18n String
 example name = do
     hello <- gettext "Hello, %s!"
     return (hello name)

withContext

Arguments

:: Maybe Context

Context to use

-> I18n a

Internationalized expression

-> I18n a

New internationalized expression

Sets a local Context for an internationalized expression. If there is no translation, then no context version is tried.

 example2 :: String -> I18n String
 example2 = withContext (Just "test") . example

withLocale

Arguments

:: Locale

Locale to use

-> I18n a

Internationalized expression

-> I18n a

New internationalized expression. Note: while this expression is localy localized already, it is to be a part of another internationalized expression. Therefore the final type is internationalized.

Sets a local Locale for an internationalized expression.

 example3 :: String -> I18n String
 example3 = withLocale (Locale "ru") . example2

UTF-8 Output Functions

putStrLn :: String -> IO ()

The same as putStr, but adds a newline character.

putStr :: String -> IO ()

Write a UTF8 string to the standard output device

module Control.Monad.Trans