Text.Boomerang.Error

An Error handling scheme that can be used with Boomerang

Documentation

data ErrorMsg

Constructors

SysUnExpect String

EOI String

UnExpect String

Expect String

Message String

Instances

Eq ErrorMsg

Data ErrorMsg

Ord ErrorMsg

Read ErrorMsg

Show ErrorMsg

Typeable * ErrorMsg

messageString :: ErrorMsg -> String

extract the String from an ErrorMsg. Note: the resulting String will not include any information about what constructor it came from.

data ParserError pos

Constructors

ParserError (Maybe pos) [ErrorMsg]

Instances

InitialPosition StringError

InitialPosition StringsError

InitialPosition TextsError

Eq pos => Eq (ParserError pos)

Data pos => Data (ParserError pos)

Ord pos => Ord (ParserError pos)

Show pos => Show (ParserError pos)

Error (ParserError p)

ErrorPosition (ParserError p)

Typeable (* -> *) ParserError

(~) * a b => IsString (Boomerang StringError String a b)

(~) * a b => IsString (Boomerang StringsError [String] a b)

(~) * a b => IsString (Boomerang TextsError [Text] a b)

type Pos (ParserError p) = p

mkParserError :: pos -> [ErrorMsg] -> [Either (ParserError pos) a]

lift a pos and '[ErrorMsg]' into a parse error

This is intended to be used inside a Parser like this:

Parser $ \tok pos -> mkParserError pos [Message "just some error..."]

(<?>) :: Boomerang (ParserError p) tok a b -> String -> Boomerang (ParserError p) tok a b infix 0

annotate a parse error with an additional Expect message

satisfy isUpper <?> 'an uppercase character'

condenseErrors :: Ord pos => [ParserError pos] -> ParserError pos

condense the ParserErrors with the highest parse position into a single ParserError

showErrorMessages :: String -> String -> String -> String -> String -> [ErrorMsg] -> String

Helper function for turning '[ErrorMsg]' into a user-friendly String

showParserError

Arguments

:: (pos -> String)

function to turn the error position into a String

-> ParserError pos

the ParserError

-> String

turn a parse error into a user-friendly error message