Types

Importance of the logged message.

These levels, listed in increasing order of importance, correspond to the levels used by syslog(3).

Path represents the hierarchical structure of logged messages.

For example, consider a df1 log line as like the following:

1999-12-20T07:11:39.230553031Z /foo x=a y=b /bar /qux z=c z=d WARNING Something

For that line, the log_path attribute of the Log datatype will contain the following:

[ Push (segment "foo")
, Attr (key "x") (value "a")
, Attr (key "y") (value "b")
, Push (segment "bar")
, Push (segment "qux")
, Attr (key "z") (value "c")
, Attr (key "z") (value "d")
] :: Seq Path

Please notice that [] :: Seq Path is a valid path insofar as df1 is concerned, and that Attr and Push can be juxtapositioned in any order.

Convert an arbitrary type to a Sequence of Paths.

You are encouraged to create custom ToPath instances for your types making sure you avoid rendering sensitive details such as passwords, so that they don't accidentally end up in logs.

Any characters that need to be escaped for rendering will be automatically escaped at rendering time. You don't need to escape them here.

A path segment.

If you have the OverloadedStrings GHC extension enabled, you can build a Segment using a string literal:

"foo" :: Segment

Otherwise, you can use fromString or segment.

Notice that "" :: Segment is acceptable, and will be correctly rendered and parsed back.

Convert an arbitrary type to a Segment.

You are encouraged to create custom ToSegment instances for your types making sure you avoid rendering sensitive details such as passwords, so that they don't accidentally end up in logs.

Any characters that need to be escaped for rendering will be automatically escaped at rendering time. You don't need to escape them here.

An attribute key (see Attr).

If you have the OverloadedStrings GHC extension enabled, you can build a Key using a string literal:

"foo" :: Key

Otherwise, you can use fromString or key.

Notice that "" :: Key is acceptable, and will be correctly rendered and parsed back.

Convert an arbitrary type to a Key.

You are encouraged to create custom ToKey instances for your types making sure you avoid rendering sensitive details such as passwords, so that they don't accidentally end up in logs.

Any characters that need to be escaped for rendering will be automatically escaped at rendering time. You don't need to escape them here.

An attribute value (see Attr).

If you have the OverloadedStrings GHC extension enabled, you can build a Value using a string literal:

"foo" :: Value

Otherwise, you can use fromString or value.

Notice that "" :: Value is acceptable, and will be correctly rendered and parsed back.

Convert an arbitrary type to a Value.

You are encouraged to create custom ToValue instances for your types making sure you avoid rendering sensitive details such as passwords, so that they don't accidentally end up in logs.

Any characters that need to be escaped for rendering will be automatically escaped at rendering time. You don't need to escape them here.

A message text.

If you have the OverloadedStrings GHC extension enabled, you can build a Message using a string literal:

"foo" :: Message

Otherwise, you can use fromString or message.

Notice that "" :: Message is acceptable, and will be correctly rendered and parsed back.

Convert an arbitrary type to a Message.

You are encouraged to create custom ToMessage instances for your types making sure you avoid rendering sensitive details such as passwords, so that they don't accidentally end up in logs.

Any characters that need to be escaped for rendering will be automatically escaped at rendering time. You don't need to escape them here.