toml is:package

Not on Stackage, so not searched.
Bidirectional TOML serialization Implementation of bidirectional TOML serialization. Simple codecs look like this:
data User = User
{ userName :: Text
, userAge  :: Int
}

userCodec :: TomlCodec User
userCodec = User
<$> Toml.text "name" .= userName
<*> Toml.int  "age"  .= userAge
The following blog post has more details about library design:
TOML 1.0.0 parser TOML parser using generated lexers and parsers with careful attention to the TOML 1.0.0 semantics for defining tables.
TOML format parser compliant with v1.0.0. See README.md for more details.
Alternative parser for TOML values produced by the toml-reader package. Package defines a set of parser combinators that allows analyzing arbitrary TOML structures. Includes formatted errors that keep track of where in the original TOML file a value came from.
Not on Stackage, so not searched. Command-line tool to check syntax of TOML files
Not on Stackage, so not searched. toml-parser test drivers
Not on Stackage, so not searched. Parser for TOML files
Not on Stackage, so not searched. Parser for TOML files
Not on Stackage, so not searched. Lenses for toml-parser
Not on Stackage, so not searched. Convert between Dhall and TOML
Not on Stackage, so not searched. Trial helper functions for tomland
Not on Stackage, so not searched. Parse TOML values produced by htoml-megaparsec package.
Not on Stackage, so not searched. Configuration Loader for toml