Copyright	(c) Daan Leijen 1999-2001 (c) Paolo Martini 2007
License	BSD-style (see the LICENSE file)
Maintainer	derek.a.elkins@gmail.com
Stability	provisional
Portability	portable
Safe Haskell	Safe
Language	Haskell2010

Text.Parsec.Error

Description

Parse errors

Synopsis

data Message
- = SysUnExpect !String
- | UnExpect !String
- | Expect !String
- | Message !String
messageString :: Message -> String
data ParseError
errorPos :: ParseError -> SourcePos
errorMessages :: ParseError -> [Message]
errorIsUnknown :: ParseError -> Bool
showErrorMessages :: String -> String -> String -> String -> String -> [Message] -> String
newErrorMessage :: Message -> SourcePos -> ParseError
newErrorUnknown :: SourcePos -> ParseError
addErrorMessage :: Message -> ParseError -> ParseError
setErrorPos :: SourcePos -> ParseError -> ParseError
setErrorMessage :: Message -> ParseError -> ParseError
mergeError :: ParseError -> ParseError -> ParseError

Documentation

data Message Source #

This abstract data type represents parse error messages. There are four kinds of messages:

 data Message = SysUnExpect String
              | UnExpect String
              | Expect String
              | Message String

The fine distinction between different kinds of parse errors allows the system to generate quite good error messages for the user. It also allows error messages that are formatted in different languages. Each kind of message is generated by different combinators:

A SysUnExpect message is automatically generated by the satisfy combinator. The argument is the unexpected input.
A UnExpect message is generated by the unexpected combinator. The argument describes the unexpected item.
A Expect message is generated by the <?> combinator. The argument describes the expected item.
A Message message is generated by the fail combinator. The argument is some general parser message.

Constructors

SysUnExpect !String
UnExpect !String
Expect !String
Message !String

Instances

Enum Message Source #
Instance details Methods succ :: Message -> Message Source # pred :: Message -> Message Source # toEnum :: Int -> Message Source # fromEnum :: Message -> Int Source # enumFrom :: Message -> [Message] Source # enumFromThen :: Message -> Message -> [Message] Source # enumFromTo :: Message -> Message -> [Message] Source # enumFromThenTo :: Message -> Message -> Message -> [Message] Source #
Eq Message Source #
Instance details Methods (==) :: Message -> Message -> Bool # (/=) :: Message -> Message -> Bool #
Ord Message Source #
Instance details Methods compare :: Message -> Message -> Ordering # (<) :: Message -> Message -> Bool # (<=) :: Message -> Message -> Bool # (>) :: Message -> Message -> Bool # (>=) :: Message -> Message -> Bool # max :: Message -> Message -> Message # min :: Message -> Message -> Message #

messageString :: Message -> String Source #

Extract the message string from an error message

data ParseError Source #

The abstract data type ParseError represents parse errors. It provides the source position (SourcePos) of the error and a list of error messages (Message). A ParseError can be returned by the function parse. ParseError is an instance of the Show and Eq classes.

Instances

Eq ParseError Source #
Instance details Methods (==) :: ParseError -> ParseError -> Bool # (/=) :: ParseError -> ParseError -> Bool #
Show ParseError Source #
Instance details Methods showsPrec :: Int -> ParseError -> ShowS Source # show :: ParseError -> String Source # showList :: [ParseError] -> ShowS Source #

errorPos :: ParseError -> SourcePos Source #

Extracts the source position from the parse error

errorMessages :: ParseError -> [Message] Source #

Extracts the list of error messages from the parse error

errorIsUnknown :: ParseError -> Bool Source #

showErrorMessages :: String -> String -> String -> String -> String -> [Message] -> String Source #

newErrorMessage :: Message -> SourcePos -> ParseError Source #

newErrorUnknown :: SourcePos -> ParseError Source #

addErrorMessage :: Message -> ParseError -> ParseError Source #

setErrorPos :: SourcePos -> ParseError -> ParseError Source #

setErrorMessage :: Message -> ParseError -> ParseError Source #

mergeError :: ParseError -> ParseError -> ParseError Source #