envparse

Parse environment variables

https://supki.github.io/envparse

Version on this page:	0.5.2
LTS Haskell 24.2:	0.6.0
Stackage Nightly 2025-07-30:	0.6.0
Latest on Hackage:	0.6.0

See all snapshots envparse appears in

BSD-3-Clause licensed by Matvey Aksenov

Maintained by [email protected]

This version can be pinned in stack with:envparse-0.5.2@sha256:4c13fc024c8b524237f17c3eb6e0233ae9abf775140c0054862f1705c3e5ce86,2849

Module documentation for 0.5.2

Env
- Env.Internal

Depends on 2 packages(full list with versions):

base, containers

Used by 1 package in nightly-2024-08-12(full list with versions):

envparse

optparse-applicative, but for environment variables

See example/Main.hs for an executable example

As to why anyone would want to use environment to configure their applications, here’s what some folks think about it.

Changes

0.5.2

Added eitherReader. (https://github.com/supki/envparse/pull/24)

0.5.1

Added configurable maximum info block width (https://github.com/supki/envparse/pull/21).
Added instance (Field e a, ...) => Field e (Maybe a) for generic environment parsing. (https://github.com/supki/envparse/pull/16)

0.5

Added char.
Fixed masking parse errors with default values. (https://github.com/supki/envparse/issues/8)
Replaced keep with sensitive. All variables are kept in the environment after a successul parse except those wrapped in sensitive. (https://github.com/supki/envparse/issues/9)

0.4.1

Supported GHC 8.4.3.

0.4

Supported GHC 8.0.1.
On GHC 7.8 and newer, as a secutiry measure, all declared variables are unset by the end of a successful parse. If you want to keep the variable in the environment, use the keep modifier. (https://github.com/supki/envparse/pull/7)

0.3.4

Added splitOn.

0.3.3

Removed the unnecessary AsEmpty and AsUnset constraints on the error type in the flag and switch parsers.

0.3.2

Added showDef.

0.3.1

Supported Generically derived Parsers on GHC 7.10.

0.3.0

Supported user-defined Reader errors. (https://github.com/supki/envparse/pull/4)
Widened the range of GHC versions to test the library with from 7.6–7.8 to 7.6–HEAD.

0.2.2

Added helpDoc, a Parser pretty-printer for use in error messages.

0.2.1

Cosmetic changes in the help output.

0.2.0

Added prefixed.
Added parseOr, a slightly generalized version of parse.
Renamed parseTest to parsePure.

0.1.0

Initial release.