lens- Lenses, Folds and Traversals

Copyright(C) 2012-2014 Edward Kmett
LicenseBSD-style (see the file LICENSE)
MaintainerEdward Kmett <ekmett@gmail.com>
Safe HaskellTrustworthy






packed :: Iso' String Text Source

This isomorphism can be used to pack (or unpack) lazy Text.

>>> "hello"^.packed -- :: Text
pack x ≡ x '^.' packed
unpack x ≡ x '^.' from packed
packedfrom unpacked

unpacked :: Iso' Text String Source

This isomorphism can be used to unpack (or pack) lazy Text.

>>> "hello"^.unpacked -- :: String
pack x ≡ x '^.' from unpacked
unpack x ≡ x '^.' packed

This Iso is provided for notational convenience rather than out of great need, since

unpackedfrom packed

text :: IndexedTraversal' Int Text Char Source

Traverse the individual characters in a Text.

>>> anyOf text (=='c') "chello"
text = unpacked . traversed

When the type is unambiguous, you can also use the more general each.


Note that when just using this as a Setter, setting map can be more efficient.

builder :: Iso' Text Builder Source

Convert between lazy Text and Builder .

fromLazyText x ≡ x '^.' builder
toLazyText x ≡ x '^.' from builder

utf8 :: Prism' ByteString Text Source

EncodeDecode a lazy Text tofrom lazy ByteString, via UTF-8.

Note: This function does not decode lazily, as it must consume the entire input before deciding whether or not it fails.

>>> ByteString.unpack (utf8 # "☃")