Documentation

A basic dependent sum type; the first component is a tag that specifies the type of the second; for example, think of a GADT such as:

data Tag a where
   AString :: Tag String
   AnInt   :: Tag Int

Then, we have the following valid expressions of type Applicative f => DSum Tag f:

AString ==> "hello!"
AnInt   ==> 42

And we can write functions that consume DSum Tag f values by matching, such as:

toString :: DSum Tag Identity -> String
toString (AString :=> Identity str) = str
toString (AnInt   :=> Identity int) = show int

By analogy to the (key => value) construction for dictionary entries in many dynamic languages, we use (key :=> value) as the constructor for dependent sums. The :=> and ==> operators have very low precedence and bind to the right, so if the Tag GADT is extended with an additional constructor Rec :: Tag (DSum Tag Identity), then Rec ==> AnInt ==> 3 + 4 is parsed as would be expected (Rec ==> (AnInt ==> (3 + 4))) and has type DSum Identity Tag. Its precedence is just above that of $, so foo bar $ AString ==> "eep" is equivalent to foo bar (AString ==> "eep").

The Lambdabot entry point. Initialise plugins, connect, and run the bot in the LB monad

Also, handle any fatal exceptions (such as non-recoverable signals), (i.e. print a message and exit). Non-fatal exceptions should be dealt with in the mainLoop or further down.

Priorities are used to define how important a log message is. Users can filter log messages based on priorities.

These have their roots on the traditional syslog system. The standard definitions are given below, but you are free to interpret them however you like. They are listed here in ascending importance order.