{-# LANGUAGE DeriveDataTypeable #-}
{- |
   Module      : Data.GraphViz.Exception
   Description : Graphviz-specific exceptions
   Copyright   : (c) Ivan Lazar Miljenovic
   License     : 3-Clause BSD-style
   Maintainer  : Ivan.Miljenovic@gmail.com
-}
module Data.GraphViz.Exception
       ( GraphvizException(..)
         -- * Re-exported for convenience.
       , mapException
       , throw
       , throwIO
       , handle
       , bracket
       ) where

import Control.Exception
import Data.Typeable

-- -----------------------------------------------------------------------------

-- | Exceptions that arise from using this library fall into four
--   categories:
--
--   * Unable to parse provided Dot code.
--
--   * Dot code is not valid UTF-8.
--
--   * An error when trying to run an external program (e.g. @dot@).
--
--   * Treating a non-custom Attribute as a custom one.
--
data GraphvizException = NotDotCode String
                       | NotUTF8Dot String
                       | GVProgramExc String
                       | NotCustomAttr String
                       deriving (GraphvizException -> GraphvizException -> Bool
(GraphvizException -> GraphvizException -> Bool)
-> (GraphvizException -> GraphvizException -> Bool)
-> Eq GraphvizException
forall a. (a -> a -> Bool) -> (a -> a -> Bool) -> Eq a
$c== :: GraphvizException -> GraphvizException -> Bool
== :: GraphvizException -> GraphvizException -> Bool
$c/= :: GraphvizException -> GraphvizException -> Bool
/= :: GraphvizException -> GraphvizException -> Bool
Eq, Eq GraphvizException
Eq GraphvizException =>
(GraphvizException -> GraphvizException -> Ordering)
-> (GraphvizException -> GraphvizException -> Bool)
-> (GraphvizException -> GraphvizException -> Bool)
-> (GraphvizException -> GraphvizException -> Bool)
-> (GraphvizException -> GraphvizException -> Bool)
-> (GraphvizException -> GraphvizException -> GraphvizException)
-> (GraphvizException -> GraphvizException -> GraphvizException)
-> Ord GraphvizException
GraphvizException -> GraphvizException -> Bool
GraphvizException -> GraphvizException -> Ordering
GraphvizException -> GraphvizException -> GraphvizException
forall a.
Eq a =>
(a -> a -> Ordering)
-> (a -> a -> Bool)
-> (a -> a -> Bool)
-> (a -> a -> Bool)
-> (a -> a -> Bool)
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-> (a -> a -> a)
-> Ord a
$ccompare :: GraphvizException -> GraphvizException -> Ordering
compare :: GraphvizException -> GraphvizException -> Ordering
$c< :: GraphvizException -> GraphvizException -> Bool
< :: GraphvizException -> GraphvizException -> Bool
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$cmax :: GraphvizException -> GraphvizException -> GraphvizException
max :: GraphvizException -> GraphvizException -> GraphvizException
$cmin :: GraphvizException -> GraphvizException -> GraphvizException
min :: GraphvizException -> GraphvizException -> GraphvizException
Ord, Typeable)

instance Show GraphvizException where
  showsPrec :: Int -> GraphvizException -> ShowS
showsPrec Int
_ (NotDotCode String
str)    = String -> ShowS
showString (String -> ShowS) -> String -> ShowS
forall a b. (a -> b) -> a -> b
$ String
"Error when parsing Dot code:\n" String -> ShowS
forall a. [a] -> [a] -> [a]
++ String
str
  showsPrec Int
_ (NotUTF8Dot String
str)    = String -> ShowS
showString (String -> ShowS) -> String -> ShowS
forall a b. (a -> b) -> a -> b
$ String
"Invalid UTF-8 Dot code: " String -> ShowS
forall a. [a] -> [a] -> [a]
++ String
str
  showsPrec Int
_ (GVProgramExc String
str)  = String -> ShowS
showString (String -> ShowS) -> String -> ShowS
forall a b. (a -> b) -> a -> b
$ String
"Error running utility program: " String -> ShowS
forall a. [a] -> [a] -> [a]
++ String
str
  showsPrec Int
_ (NotCustomAttr String
str) = String -> ShowS
showString (String -> ShowS) -> String -> ShowS
forall a b. (a -> b) -> a -> b
$ String
"Not a custom Attribute: " String -> ShowS
forall a. [a] -> [a] -> [a]
++ String
str

instance Exception GraphvizException