From 030d3b597de696a074ff143958f359de268d2078 Mon Sep 17 00:00:00 2001
From: John MacFarlane <jgm@berkeley.edu>
Date: Sun, 18 Jan 2015 22:04:42 -0800
Subject: [PATCH] Custom writer: Raise `PandocLuaException` instead of using
'error'.
Eventually we'll change the return type so that no exception
is involved, but at least this can be trapped.
---
src/Text/Pandoc/Writers/Custom.hs | 11 +++++++++--
1 file changed, 9 insertions(+), 2 deletions(-)
diff --git a/src/Text/Pandoc/Writers/Custom.hs b/src/Text/Pandoc/Writers/Custom.hs
index 3e4c80a53..6fc3b9b3c 100644
--- a/src/Text/Pandoc/Writers/Custom.hs
+++ b/src/Text/Pandoc/Writers/Custom.hs
@@ -1,5 +1,5 @@
{-# LANGUAGE OverlappingInstances, FlexibleInstances, OverloadedStrings,
- ScopedTypeVariables #-}
+ ScopedTypeVariables, DeriveDataTypeable #-}
{-# OPTIONS_GHC -fno-warn-orphans #-}
{- Copyright (C) 2012-2014 John MacFarlane <jgm@berkeley.edu>
@@ -35,6 +35,7 @@ import Text.Pandoc.Definition
import Text.Pandoc.Options
import Data.List ( intersperse )
import Data.Char ( toLower )
+import Data.Typeable
import Scripting.Lua (LuaState, StackValue, callfunc)
import Text.Pandoc.Writers.Shared
import qualified Scripting.Lua as Lua
@@ -43,6 +44,7 @@ import Data.ByteString (ByteString)
import qualified Data.ByteString.Char8 as C8
import Data.Monoid
import Control.Monad (when)
+import Control.Exception
import qualified Data.Map as M
import Text.Pandoc.Templates
@@ -146,6 +148,11 @@ instance StackValue Citation where
peek = undefined
valuetype _ = Lua.TTABLE
+data PandocLuaException = PandocLuaException String
+ deriving (Show, Typeable)
+
+instance Exception PandocLuaException
+
-- | Convert Pandoc to custom markup.
writeCustom :: FilePath -> WriterOptions -> Pandoc -> IO String
writeCustom luaFile opts doc@(Pandoc meta _) = do
@@ -156,7 +163,7 @@ writeCustom luaFile opts doc@(Pandoc meta _) = do
-- check for error in lua script (later we'll change the return type
-- to handle this more gracefully):
when (status /= 0) $
- Lua.tostring lua 1 >>= error
+ Lua.tostring lua 1 >>= throw . PandocLuaException
Lua.call lua 0 0
-- TODO - call hierarchicalize, so we have that info
rendered <- docToCustom lua opts doc