Debug.Record

Module for recording and manipulating debug traces. For most users, the TemplateHaskell helpers in Debug should be sufficient.

Recording

data Function

Metadata about a function, used to drive the HTML view.

Constructors

Function

Fields

• funName :: String

  Function name

• funSource :: String

  Function source, using n to break lines

• funArguments :: [String]

  Variables for the arguments to the function

• funResult :: String

  Variable for the result of the function

Instances

Eq Function

Methods

(==) :: Function -> Function -> Bool

(/=) :: Function -> Function -> Bool

Ord Function

Methods

compare :: Function -> Function -> Ordering

(<) :: Function -> Function -> Bool

(<=) :: Function -> Function -> Bool

(>) :: Function -> Function -> Bool

(>=) :: Function -> Function -> Bool

max :: Function -> Function -> Function

min :: Function -> Function -> Function

Show Function

Methods

showsPrec :: Int -> Function -> ShowS

show :: Function -> String

showList :: [Function] -> ShowS

data Call

A single function call, used to attach additional information

funInfo :: Show a => Function -> (Call -> a) -> a

A version of fun allowing you to pass further information about the Function which is used when showing debug views.

fun :: Show a => String -> (Call -> a) -> a

Called under a lambda with a function name to provide a unique context for a particular call, e.g.:

tracedAdd x y = fun "add" $ \t -> var t "x" x + var t "y" y

This function involves giving identity to function calls, so is unsafe, and will only work under a lambda.

var :: Show a => Call -> String -> a -> a

Used in conjunction with fun to annotate variables. See fun for an example.

Viewing

debugClear :: IO ()

Clear all debug information. Useful when working in ghci to reset any previous debugging work and reduce the amount of output.

debugPrint :: IO ()

Print information about the observed function calls to stdout, in a human-readable format.

debugJSON :: IO String

Obtain information about observed functions in JSON format. The JSON format is not considered a stable part of the interface, more presented as a back door to allow exploration of alternative views.

debugView :: IO ()

Open a web browser showing information about observed functions.

debugSave :: FilePath -> IO ()

Save information about observed functions to the specified file, in HTML format.

Orphan instances

Show a

An orphan instance of Show that maps anything without a Show instance to ?. Suitable for use only when debugging.

Methods

showsPrec :: Int -> a -> ShowS

show :: a -> String

showList :: [a] -> ShowS