[gentoo-commits] repo/gentoo:master commit in: dev-haskell/edisoncore/files/, dev-haskell/edisoncore/

[Sergei Trofimovich]

commit:     537a81be2b06a3637494c8c01726dbfcc7dfceb0
Author:     Sergei Trofimovich <slyfox <AT> gentoo <DOT> org>
AuthorDate: Tue Oct 13 06:49:54 2020 +0000
Commit:     Sergei Trofimovich <slyfox <AT> gentoo <DOT> org>
CommitDate: Tue Oct 13 06:50:17 2020 +0000
URL:        https://gitweb.gentoo.org/repo/gentoo.git/commit/?id=537a81be

dev-haskell/edisoncore: move large patch out of files/

Reported-by: Joonas Niilola
Closes: https://bugs.gentoo.org/748165
Package-Manager: Portage-3.0.8, Repoman-3.0.1
Signed-off-by: Sergei Trofimovich <slyfox <AT> gentoo.org>

 dev-haskell/edisoncore/Manifest                    |    1 +
 .../edisoncore/edisoncore-1.3.2.1-r1.ebuild        |    9 +-
 .../files/edisoncore-1.3.2.1-ghc-8.8.patch         | 1268 --------------------
 3 files changed, 7 insertions(+), 1271 deletions(-)

diff --git a/dev-haskell/edisoncore/Manifest b/dev-haskell/edisoncore/Manifest
index 537ebb856cf..a583e0ce2d1 100644
--- a/dev-haskell/edisoncore/Manifest
+++ b/dev-haskell/edisoncore/Manifest
@@ -1 +1,2 @@
 DIST EdisonCore-1.3.2.1.tar.gz 82522 BLAKE2B 758e02e462d4f86b95a66792ce26dda6d1a00506a8071f3716f9a7484fc992af9e1709a9bbb958ee71175b2c51c4574493a35b6eaa7a1bfab415ed4ce7e2a8b4 SHA512 6812b04edb1abdfc2486d66bb86d6370b76667de1603ab421d92a6ecc17a25014e0ab97f53dd4f1e75cacf32c31611e8f2dd6c740c840e349c3c762ae00df65f
+DIST edisoncore-1.3.2.1-ghc-8.8.patch 57508 BLAKE2B 0651b4be26461cfe2bd3a57742ee138863ec6b47940065754642bd6320d814dfc8cb63bd4b37131bb3135752d03cdab335c2f1ebf5ccd87bd9219bd39d43c3e3 SHA512 9e5b60ec6023f2be4af4ecae0fcf00f8b6f758ea6bbd21c3dea4d3dd9ff128736e743e9a020a445e27e4ff1fb6c43061427f042353fe84528f2d715b5784302b

diff --git a/dev-haskell/edisoncore/edisoncore-1.3.2.1-r1.ebuild b/dev-haskell/edisoncore/edisoncore-1.3.2.1-r1.ebuild
index 87a59c476f7..c2550f9bba9 100644
--- a/dev-haskell/edisoncore/edisoncore-1.3.2.1-r1.ebuild
+++ b/dev-haskell/edisoncore/edisoncore-1.3.2.1-r1.ebuild
@@ -1,4 +1,4 @@
-# Copyright 1999-2019 Gentoo Authors
+# Copyright 1999-2020 Gentoo Authors
 # Distributed under the terms of the GNU General Public License v2
 
 EAPI=7
@@ -13,7 +13,10 @@ MY_P="${MY_PN}-${PV}"
 
 DESCRIPTION="A library of efficent, purely-functional data structures (Core Implementations)"
 HOMEPAGE="http://rwd.rdockins.name/edison/home/"
-SRC_URI="https://hackage.haskell.org/package/${MY_P}/${MY_P}.tar.gz"
+SRC_URI="
+	https://hackage.haskell.org/package/${MY_P}/${MY_P}.tar.gz
+	https://dev.gentoo.org/~slyfox/distfiles/edisoncore-1.3.2.1-ghc-8.8.patch
+"
 
 LICENSE="MIT"
 SLOT="0/${PV}"
@@ -32,4 +35,4 @@ DEPEND="${RDEPEND}
 
 S="${WORKDIR}/${MY_P}"
 
-PATCHES=( "${FILESDIR}/${PN}-1.3.2.1-ghc-8.8.patch" )
+PATCHES=( "${DISTDIR}/${PN}-1.3.2.1-ghc-8.8.patch" )

diff --git a/dev-haskell/edisoncore/files/edisoncore-1.3.2.1-ghc-8.8.patch b/dev-haskell/edisoncore/files/edisoncore-1.3.2.1-ghc-8.8.patch
deleted file mode 100644
index 5589433edc6..00000000000
--- a/dev-haskell/edisoncore/files/edisoncore-1.3.2.1-ghc-8.8.patch
+++ /dev/null
@@ -1,1268 +0,0 @@
-diff --git a/EdisonCore.cabal b/EdisonCore.cabal
-index 901cd83..ad1af00 100644
---- a/EdisonCore.cabal
-+++ b/EdisonCore.cabal
-@@ -62,8 +62,10 @@ Library
-      array
- 
-   if impl(ghc < 8.0)
--    -- Provide/emulate Data.Semigroups` API for pre-GHC-8
--    Build-Depends: semigroups == 0.18.*
-+    Build-Depends:
-+      fail,
-+      -- Provide/emulate Data.Semigroups` API for pre-GHC-8
-+      semigroups == 0.18.*
- 
-   Default-Language: Haskell2010
-   Default-Extensions:
-diff --git a/src/Data/Edison/Assoc/AssocList.hs b/src/Data/Edison/Assoc/AssocList.hs
-index c577492..15d9884 100644
---- a/src/Data/Edison/Assoc/AssocList.hs
-+++ b/src/Data/Edison/Assoc/AssocList.hs
-@@ -58,8 +58,9 @@ import Prelude hiding (null,map,lookup,foldr,foldl,foldr1,foldl1,filter)
- import qualified Prelude
- import Data.Monoid
- import Data.Semigroup as SG
--import Control.Monad.Identity
-+import qualified Control.Monad.Fail as Fail
- import qualified Data.Edison.Assoc as A
-+import Data.Edison.Prelude ( runFail_ )
- import qualified Data.Edison.Seq as S
- import qualified Data.Edison.Seq.BinaryRandList as RL
- import Data.Edison.Assoc.Defaults
-@@ -82,10 +83,10 @@ size          :: Eq k => FM k a -> Int
- member        :: Eq k => k -> FM k a -> Bool
- count         :: Eq k => k -> FM k a -> Int
- lookup        :: Eq k => k -> FM k a -> a
--lookupM       :: (Eq k, Monad rm) => k -> FM k a -> rm a
-+lookupM       :: (Eq k, Fail.MonadFail rm) => k -> FM k a -> rm a
- lookupAll     :: (Eq k,S.Sequence seq) => k -> FM k a -> seq a
- lookupAndDelete    :: Eq k => k -> FM k a -> (a,FM k a)
--lookupAndDeleteM   :: (Eq k,Monad rm)   => k -> FM k a -> rm (a,FM k a)
-+lookupAndDeleteM   :: (Eq k, Fail.MonadFail rm)   => k -> FM k a -> rm (a,FM k a)
- lookupAndDeleteAll :: (Eq k,S.Sequence seq) => k -> FM k a -> (seq a,FM k a)
- lookupWithDefault  :: Eq k => a -> k -> FM k a -> a
- adjust             :: Eq k => (a -> a) -> k -> FM k a -> FM k a
-@@ -143,11 +144,11 @@ unionSeqWithKey  :: (Eq k,S.Sequence seq) =>
-                         (k -> a -> a -> a) -> seq (FM k a) -> FM k a
- intersectionWithKey :: Eq k => (k -> a -> b -> c) -> FM k a -> FM k b -> FM k c
- 
--minView          :: (Ord k,Monad m) => FM k a -> m (a,FM k a)
-+minView          :: (Ord k, Fail.MonadFail m) => FM k a -> m (a,FM k a)
- minElem          :: Ord k => FM k a -> a
- deleteMin        :: Ord k => FM k a -> FM k a
- unsafeInsertMin  :: Ord k => k -> a -> FM k a -> FM k a
--maxView          :: (Ord k,Monad m) => FM k a -> m (a,FM k a)
-+maxView          :: (Ord k, Fail.MonadFail m) => FM k a -> m (a,FM k a)
- maxElem          :: Ord k => FM k a -> a
- deleteMax        :: Ord k => FM k a -> FM k a
- unsafeInsertMax  :: Ord k => k -> a -> FM k a -> FM k a
-@@ -169,9 +170,9 @@ partitionLT_GE   :: Ord k => k -> FM k a -> (FM k a,FM k a)
- partitionLE_GT   :: Ord k => k -> FM k a -> (FM k a,FM k a)
- partitionLT_GT   :: Ord k => k -> FM k a -> (FM k a,FM k a)
- 
--minViewWithKey    :: (Ord k,Monad m) => FM k a -> m ((k, a), FM k a)
-+minViewWithKey    :: (Ord k, Fail.MonadFail m) => FM k a -> m ((k, a), FM k a)
- minElemWithKey    :: Ord k => FM k a -> (k,a)
--maxViewWithKey    :: (Ord k,Monad m) => FM k a -> m ((k, a), FM k a)
-+maxViewWithKey    :: (Ord k, Fail.MonadFail m) => FM k a -> m ((k, a), FM k a)
- maxElemWithKey    :: Ord k => FM k a -> (k,a)
- foldrWithKey      :: Ord k => (k -> a -> b -> b) -> b -> FM k a -> b
- foldlWithKey      :: Ord k => (b -> k -> a -> b) -> b -> FM k a -> b
-@@ -309,7 +310,7 @@ count _ E = 0
- count key (I k _ m) | key == k  = 1
-                     | otherwise = count key m
- 
--lookup key m = runIdentity (lookupM key m)
-+lookup key m = runFail_ (lookupM key m)
- 
- lookupM _ E = fail "AssocList.lookup: lookup failed"
- lookupM key (I k x m) | key == k  = return x
-@@ -319,7 +320,7 @@ lookupAll _ E = S.empty
- lookupAll key (I k x m) | key == k  = S.singleton x
-                         | otherwise = lookupAll key m
- 
--lookupAndDelete key m = runIdentity (lookupAndDeleteM key m)
-+lookupAndDelete key m = runFail_ (lookupAndDeleteM key m)
- 
- lookupAndDeleteM _ E = fail "AssocList.lookupAndDeleteM: lookup failed"
- lookupAndDeleteM key (I k x m)
-diff --git a/src/Data/Edison/Assoc/Defaults.hs b/src/Data/Edison/Assoc/Defaults.hs
-index a9ef520..8e2b37d 100644
---- a/src/Data/Edison/Assoc/Defaults.hs
-+++ b/src/Data/Edison/Assoc/Defaults.hs
-@@ -15,6 +15,8 @@ module Data.Edison.Assoc.Defaults where
- 
- import Prelude hiding (null,map,lookup,foldr,foldl,foldr1,foldl1,filter)
- 
-+import qualified Control.Monad.Fail as Fail
-+
- import Data.Edison.Assoc
- import qualified Data.Edison.Seq as S
- import qualified Data.Edison.Seq.ListSeq as L
-@@ -190,7 +192,7 @@ lookupAndDeleteDefault k m =
-      Nothing -> error (instanceName m ++ ".lookupAndDelete: lookup failed")
-      Just x  -> (x, delete k m)
- 
--lookupAndDeleteMDefault :: (Monad rm, AssocX m k) => k -> m a -> rm (a, m a)
-+lookupAndDeleteMDefault :: (Fail.MonadFail rm, AssocX m k) => k -> m a -> rm (a, m a)
- lookupAndDeleteMDefault k m =
-   case lookupM k m of
-      Nothing -> fail (instanceName m ++ ".lookupAndDelete: lookup failed")
-diff --git a/src/Data/Edison/Assoc/PatriciaLoMap.hs b/src/Data/Edison/Assoc/PatriciaLoMap.hs
-index 3073f83..43c2d85 100644
---- a/src/Data/Edison/Assoc/PatriciaLoMap.hs
-+++ b/src/Data/Edison/Assoc/PatriciaLoMap.hs
-@@ -55,10 +55,11 @@ module Data.Edison.Assoc.PatriciaLoMap (
- 
- import Prelude hiding (null,map,lookup,foldr,foldl,foldr1,foldl1,filter)
- import qualified Prelude
--import Control.Monad.Identity (runIdentity)
-+import qualified Control.Monad.Fail as Fail
- import Data.Monoid
- import Data.Semigroup as SG
- import qualified Data.Edison.Assoc as A
-+import Data.Edison.Prelude ( runFail_ )
- import qualified Data.Edison.Seq as S
- import qualified Data.Edison.Seq.ListSeq as L
- import Data.Edison.Assoc.Defaults
-@@ -210,9 +211,9 @@ member k (L j _) = (j == k)
- member k (B _ m t0 t1) = if zeroBit k m then member k t0 else member k t1
- 
- lookup :: Int -> FM a -> a
--lookup k m = runIdentity (lookupM k m)
-+lookup k m = runFail_ (lookupM k m)
- 
--lookupM :: (Monad rm) => Int -> FM a -> rm a
-+lookupM :: (Fail.MonadFail rm) => Int -> FM a -> rm a
- lookupM _ E = fail "PatriciaLoMap.lookup: lookup failed"
- lookupM k (L j x)
-   | j == k    = return x
-@@ -233,7 +234,7 @@ lookupAndDelete        = doLookupAndDelete
-                            (error "PatriciaLoMap.lookupAndDelete: lookup failed")
-                            (,)
- 
--lookupAndDeleteM :: Monad m => Int -> FM a -> m (a, FM a)
-+lookupAndDeleteM :: Fail.MonadFail m => Int -> FM a -> m (a, FM a)
- lookupAndDeleteM       = doLookupAndDelete
-                            (fail "PatriciaLoMap.lookupAndDelete: lookup failed")
-                            (\x m -> return (x,m))
-@@ -583,25 +584,25 @@ ordListFM_rev (B _ _ t0 t1) = merge (ordListFM_rev t0) (ordListFM_rev t1)
-             GT -> x : merge xs (y:ys)
-             EQ -> error "PatriciaLoMap: bug in ordListFM_rev"
- 
--minView :: Monad m => FM a -> m (a, FM a)
-+minView :: Fail.MonadFail m => FM a -> m (a, FM a)
- minView fm =
-    case ordListFM fm of
-      [] -> fail $ moduleName++".minView: empty map"
-      ((k,x):_) -> return (x,delete k fm)
- 
--minViewWithKey :: Monad m => FM a -> m ((Int, a), FM a)
-+minViewWithKey :: Fail.MonadFail m => FM a -> m ((Int, a), FM a)
- minViewWithKey fm =
-    case ordListFM fm of
-      [] -> fail $ moduleName++".minViewWithKey: empty map"
-      ((k,x):_) -> return ((k,x),delete k fm)
- 
--maxView :: Monad m => FM a -> m (a, FM a)
-+maxView :: Fail.MonadFail m => FM a -> m (a, FM a)
- maxView fm =
-   case ordListFM_rev fm of
-      [] -> fail $ moduleName++".maxView: empty map"
-      ((k,x):_) -> return (x,delete k fm)
- 
--maxViewWithKey :: Monad m => FM a -> m ((Int, a), FM a)
-+maxViewWithKey :: Fail.MonadFail m => FM a -> m ((Int, a), FM a)
- maxViewWithKey fm =
-    case ordListFM_rev fm of
-      [] -> fail $ moduleName++".maxViewWithKey: empty map"
-diff --git a/src/Data/Edison/Assoc/StandardMap.hs b/src/Data/Edison/Assoc/StandardMap.hs
-index 5ca48c5..e7b6a0e 100644
---- a/src/Data/Edison/Assoc/StandardMap.hs
-+++ b/src/Data/Edison/Assoc/StandardMap.hs
-@@ -51,6 +51,7 @@ module Data.Edison.Assoc.StandardMap (
- 
- import Prelude hiding (null,map,lookup,foldr,foldl,foldr1,foldl1,filter)
- import qualified Prelude
-+import qualified Control.Monad.Fail as Fail
- import qualified Data.Edison.Assoc as A
- import qualified Data.Edison.Seq as S
- import qualified Data.Edison.Seq.ListSeq as L
-@@ -81,10 +82,10 @@ member            :: Ord k => k -> FM k a -> Bool
- count             :: Ord k => k -> FM k a -> Int
- lookup            :: Ord k => k -> FM k a -> a
- lookupAll         :: (Ord k,S.Sequence seq) => k -> FM k a -> seq a
--lookupM           :: (Ord k,Monad m) => k -> FM k a -> m a
-+lookupM           :: (Ord k, Fail.MonadFail m) => k -> FM k a -> m a
- lookupWithDefault :: Ord k => a -> k -> FM k a -> a
- lookupAndDelete   :: Ord k => k -> FM k a -> (a, FM k a)
--lookupAndDeleteM  :: (Ord k,Monad m) => k -> FM k a -> m (a, FM k a)
-+lookupAndDeleteM  :: (Ord k, Fail.MonadFail m) => k -> FM k a -> m (a, FM k a)
- lookupAndDeleteAll :: (Ord k,S.Sequence seq) => k -> FM k a -> (seq a,FM k a)
- adjust            :: Ord k => (a->a) -> k -> FM k a -> FM k a
- adjustAll         :: Ord k => (a->a) -> k -> FM k a -> FM k a
-@@ -103,11 +104,11 @@ filter            :: Ord k => (a -> Bool) -> FM k a -> FM k a
- partition         :: Ord k => (a -> Bool) -> FM k a -> (FM k a,FM k a)
- elements          :: (Ord k,S.Sequence seq) => FM k a -> seq a
- 
--minView           :: (Ord k,Monad m) => FM k a -> m (a, FM k a)
-+minView           :: (Ord k, Fail.MonadFail m) => FM k a -> m (a, FM k a)
- minElem           :: Ord k => FM k a -> a
- deleteMin         :: Ord k => FM k a -> FM k a
- unsafeInsertMin   :: Ord k => k -> a -> FM k a -> FM k a
--maxView           :: (Ord k,Monad m) => FM k a -> m (a, FM k a)
-+maxView           :: (Ord k, Fail.MonadFail m) => FM k a -> m (a, FM k a)
- maxElem           :: Ord k => FM k a -> a
- deleteMax         :: Ord k => FM k a -> FM k a
- unsafeInsertMax   :: Ord k => k -> a -> FM k a -> FM k a
-@@ -165,9 +166,9 @@ foldWithKey'      :: Ord k => (k -> a -> b -> b) -> b -> FM k a -> b
- filterWithKey     :: Ord k => (k -> a -> Bool) -> FM k a -> FM k a
- partitionWithKey  :: Ord k => (k -> a -> Bool) -> FM k a -> (FM k a,FM k a)
- 
--minViewWithKey    :: (Ord k,Monad m) => FM k a -> m ((k, a), FM k a)
-+minViewWithKey    :: (Ord k, Fail.MonadFail m) => FM k a -> m ((k, a), FM k a)
- minElemWithKey    :: Ord k => FM k a -> (k,a)
--maxViewWithKey    :: (Ord k,Monad m) => FM k a -> m ((k, a), FM k a)
-+maxViewWithKey    :: (Ord k, Fail.MonadFail m) => FM k a -> m ((k, a), FM k a)
- maxElemWithKey    :: Ord k => FM k a -> (k,a)
- foldrWithKey      :: (k -> a -> b -> b) -> b -> FM k a -> b
- foldlWithKey      :: (b -> k -> a -> b) -> b -> FM k a -> b
-diff --git a/src/Data/Edison/Assoc/TernaryTrie.hs b/src/Data/Edison/Assoc/TernaryTrie.hs
-index 8b2dd57..431b348 100644
---- a/src/Data/Edison/Assoc/TernaryTrie.hs
-+++ b/src/Data/Edison/Assoc/TernaryTrie.hs
-@@ -55,8 +55,10 @@ module Data.Edison.Assoc.TernaryTrie (
- import Prelude hiding (null,map,lookup,foldr,foldl,foldr1,foldl1,filter)
- import qualified Prelude
- import qualified Data.Edison.Assoc as A
-+import Data.Edison.Prelude ( runFail_ )
- import qualified Data.Edison.Seq as S
- import qualified Data.List as L
-+import qualified Control.Monad.Fail as Fail
- import Control.Monad.Identity
- import Data.Monoid
- import Data.Semigroup as SG
-@@ -83,10 +85,10 @@ size          :: Ord k => FM k a -> Int
- member        :: Ord k => [k] -> FM k a -> Bool
- count         :: Ord k => [k] -> FM k a -> Int
- lookup        :: Ord k => [k] -> FM k a -> a
--lookupM       :: (Ord k, Monad rm) => [k] -> FM k a -> rm a
-+lookupM       :: (Ord k, Fail.MonadFail rm) => [k] -> FM k a -> rm a
- lookupAll     :: (Ord k,S.Sequence seq) => [k] -> FM k a -> seq a
- lookupAndDelete    :: Ord k => [k] -> FM k a -> (a, FM k a)
--lookupAndDeleteM   :: (Ord k, Monad rm) => [k] -> FM k a -> rm (a, FM k a)
-+lookupAndDeleteM   :: (Ord k, Fail.MonadFail rm) => [k] -> FM k a -> rm (a, FM k a)
- lookupAndDeleteAll :: (Ord k, S.Sequence seq) => [k] -> FM k a -> (seq a,FM k a)
- lookupWithDefault  :: Ord k => a -> [k] -> FM k a -> a
- adjust        :: Ord k => (a -> a) -> [k] -> FM k a -> FM k a
-@@ -527,7 +529,7 @@ member = memberUsingLookupM
- 
- count = countUsingMember
- 
--lookup m k = runIdentity (lookupM m k)
-+lookup m k = runFail_ (lookupM m k)
- 
- lookupM [] (FM Nothing _)
-   = fail "TernaryTrie.lookup: lookup failed"
-@@ -854,18 +856,18 @@ intersectionWithKey f
- 
- -- OrdAssocX
- 
--minViewFMB :: Monad m => FMB k a -> (FMB k a -> FM k a) -> m (a, FM k a)
-+minViewFMB :: Fail.MonadFail m => FMB k a -> (FMB k a -> FM k a) -> m (a, FM k a)
- minViewFMB E _ = fail $ moduleName++".minView: empty map"
- minViewFMB (I i k (Just v) E m r)        f = return (v, f (I i k Nothing E m r))
- minViewFMB (I _ _ Nothing  E (FMB' E) _) _ = error $ moduleName++".minView: bug!"
- minViewFMB (I _ k Nothing  E (FMB' m) r) f = minViewFMB m (\m' -> f (mkVBalancedFMB k Nothing E (FMB' m') r))
- minViewFMB (I _ k mv l m r)              f = minViewFMB l (\l' -> f (mkVBalancedFMB k mv l' m r))
- 
--minView :: Monad m => FM k a -> m (a,FM k a)
-+minView :: Fail.MonadFail m => FM k a -> m (a,FM k a)
- minView (FM (Just v) fmb) = return (v, FM Nothing fmb)
- minView (FM Nothing fmb)  = minViewFMB fmb (FM Nothing)
- 
--minViewWithKeyFMB :: Monad m => FMB k a -> ([k] -> [k]) -> (FMB k a -> FM k a) -> m (([k],a),FM k a)
-+minViewWithKeyFMB :: Fail.MonadFail m => FMB k a -> ([k] -> [k]) -> (FMB k a -> FM k a) -> m (([k],a),FM k a)
- minViewWithKeyFMB E _ _ = fail $ moduleName++".minView: empty map"
- minViewWithKeyFMB (I i k (Just v) E m r)        kf f = return ((kf [k],v),f (I i k Nothing E m r))
- minViewWithKeyFMB (I _ _ Nothing  E (FMB' E) _) _ _ = error $ moduleName++".minViewWithKey: bug!"
-@@ -874,7 +876,7 @@ minViewWithKeyFMB (I _ k Nothing  E (FMB' m) r) kf f = minViewWithKeyFMB m (kf .
- minViewWithKeyFMB (I _ k mv l m r)              kf f = minViewWithKeyFMB l kf
-                                                         (\l' -> f (mkVBalancedFMB k mv l' m r))
- 
--minViewWithKey :: Monad m => FM k a -> m (([k],a),FM k a)
-+minViewWithKey :: Fail.MonadFail m => FM k a -> m (([k],a),FM k a)
- minViewWithKey (FM (Just v) fmb) = return (([],v),FM Nothing fmb)
- minViewWithKey (FM Nothing fmb)  = minViewWithKeyFMB fmb id (FM Nothing)
- 
-@@ -906,7 +908,7 @@ deleteMin = deleteMinUsingMinView
- unsafeInsertMin :: Ord k => [k] -> a -> FM k a -> FM k a
- unsafeInsertMin = insert
- 
--maxViewFMB :: Monad m => FMB k a -> (FMB k a -> FM k a) -> m (a, FM k a)
-+maxViewFMB :: Fail.MonadFail m => FMB k a -> (FMB k a -> FM k a) -> m (a, FM k a)
- maxViewFMB (I _ _ (Just v) l (FMB' E) E) f = return (v, f l)
- --maxViewFMB (I i k (Just v) l (FMB' E) E) f = return (v, f (I i k Nothing l (FMB' E) E))
- maxViewFMB (I _ _ Nothing  _ (FMB' E) E) _ = error $ moduleName++".maxView: bug!"
-@@ -914,7 +916,7 @@ maxViewFMB (I i k mv l (FMB' m) E)       f = maxViewFMB m (\m' -> f (I i k mv l
- maxViewFMB (I _ k mv l m r)              f = maxViewFMB r (\r' -> f (mkVBalancedFMB k mv l m r'))
- maxViewFMB E                             _ = error $ moduleName++".maxView: bug!"
- 
--maxView :: Monad m => FM k a -> m (a, FM k a)
-+maxView :: Fail.MonadFail m => FM k a -> m (a, FM k a)
- maxView (FM Nothing E)  = fail $ moduleName++".maxView: empty map"
- maxView (FM (Just v) E) = return (v,FM Nothing E)
- maxView (FM mv fmb)     = maxViewFMB fmb (FM mv)
-@@ -930,7 +932,7 @@ maxViewWithKeyFMB (I _ k mv l m r)              kf f = maxViewWithKeyFMB r kf
- maxViewWithKeyFMB E                             _ _ = error $ moduleName++".maxViewWithKey: bug!"
- 
- 
--maxViewWithKey :: Monad m => FM k a -> m (([k],a), FM k a)
-+maxViewWithKey :: Fail.MonadFail m => FM k a -> m (([k],a), FM k a)
- maxViewWithKey (FM Nothing E)  = fail $ moduleName++".maxViewWithKey: empty map"
- maxViewWithKey (FM (Just v) E) = return (([],v),FM Nothing E)
- maxViewWithKey (FM mv fmb)     = maxViewWithKeyFMB fmb id (FM mv)
-diff --git a/src/Data/Edison/Coll/Defaults.hs b/src/Data/Edison/Coll/Defaults.hs
-index 213ed36..d927f38 100644
---- a/src/Data/Edison/Coll/Defaults.hs
-+++ b/src/Data/Edison/Coll/Defaults.hs
-@@ -14,8 +14,9 @@
- module Data.Edison.Coll.Defaults where
- 
- import Prelude hiding (null,foldr,foldl,foldr1,foldl1,lookup,filter)
--import Control.Monad.Identity
-+import qualified Control.Monad.Fail as Fail
- 
-+import Data.Edison.Prelude ( runFail_ )
- import Data.Edison.Coll
- import qualified Data.Edison.Seq as S
- import qualified Data.Edison.Seq.ListSeq as L
-@@ -81,7 +82,7 @@ disjointUsingToOrdList xs ys = disj (toOrdList xs) (toOrdList ys)
-         disj _ _ = True
- 
- intersectWitnessUsingToOrdList ::
--        (OrdColl c a, Monad m) => c -> c -> m (a,a)
-+        (OrdColl c a, Fail.MonadFail m) => c -> c -> m (a,a)
- intersectWitnessUsingToOrdList as bs = witness (toOrdList as) (toOrdList bs)
-   where witness a@(x:xs) b@(y:ys) =
-           case compare x y of
-@@ -92,7 +93,7 @@ intersectWitnessUsingToOrdList as bs = witness (toOrdList as) (toOrdList bs)
-         witness _ _ = fail $ instanceName as ++ ".intersect: failed"
- 
- lookupUsingLookupM :: Coll c a => a -> c -> a
--lookupUsingLookupM x ys = runIdentity (lookupM x ys)
-+lookupUsingLookupM x ys = runFail_ (lookupM x ys)
- 
- lookupUsingLookupAll :: Coll c a => a -> c -> a
- lookupUsingLookupAll x ys =
-@@ -100,7 +101,7 @@ lookupUsingLookupAll x ys =
-     (y:_) -> y
-     [] -> error $ instanceName ys ++ ".lookup: lookup failed"
- 
--lookupMUsingLookupAll :: (Coll c a, Monad m) => a -> c -> m a
-+lookupMUsingLookupAll :: (Coll c a, Fail.MonadFail m) => a -> c -> m a
- lookupMUsingLookupAll x ys =
-   case lookupAll x ys of
-     (y:_) -> return y
-diff --git a/src/Data/Edison/Coll/EnumSet.hs b/src/Data/Edison/Coll/EnumSet.hs
-index c93ab07..cce68e6 100644
---- a/src/Data/Edison/Coll/EnumSet.hs
-+++ b/src/Data/Edison/Coll/EnumSet.hs
-@@ -157,6 +157,7 @@ module Data.Edison.Coll.EnumSet (
- 
- import qualified Prelude
- import Prelude hiding (filter,foldl,foldr,null,map,lookup,foldl1,foldr1)
-+import qualified Control.Monad.Fail as Fail
- import qualified Data.Bits as Bits
- import Data.Bits hiding (complement)
- import Data.Word
-@@ -251,7 +252,7 @@ count = countUsingMember
- lookup :: (Eq a, Enum a) => a -> Set a -> a
- lookup = lookupUsingLookupAll
- 
--lookupM :: (Eq a, Enum a, Monad m) => a -> Set a -> m a
-+lookupM :: (Eq a, Enum a, Fail.MonadFail m) => a -> Set a -> m a
- lookupM x s
-    | member x s = return x
-    | otherwise  = fail (moduleName++".lookupM: lookup failed")
-@@ -340,12 +341,12 @@ deleteMax (Set w)
-    | w == 0    = empty
-    | otherwise = Set $ clearBit w $ msb w
- 
--minView :: (Enum a, Monad m) => Set a -> m (a, Set a)
-+minView :: (Enum a, Fail.MonadFail m) => Set a -> m (a, Set a)
- minView (Set w)
-    | w == 0    = fail (moduleName++".minView: empty set")
-    | otherwise = let i = lsb w in return (toEnum i,Set $ clearBit w i)
- 
--maxView :: (Enum a, Monad m) => Set a -> m (a, Set a)
-+maxView :: (Enum a, Fail.MonadFail m) => Set a -> m (a, Set a)
- maxView (Set w)
-    | w == 0    = fail (moduleName++".maxView: empty set")
-    | otherwise = let i = msb w in return (toEnum i, Set $ clearBit w i)
-diff --git a/src/Data/Edison/Coll/LazyPairingHeap.hs b/src/Data/Edison/Coll/LazyPairingHeap.hs
-index e41ce2e..3dcebe4 100644
---- a/src/Data/Edison/Coll/LazyPairingHeap.hs
-+++ b/src/Data/Edison/Coll/LazyPairingHeap.hs
-@@ -49,6 +49,7 @@ import Data.List (sort)
- import Data.Monoid
- import Data.Semigroup as SG
- import Control.Monad
-+import qualified Control.Monad.Fail as Fail
- import Test.QuickCheck
- 
- moduleName :: String
-@@ -359,7 +360,7 @@ lookupAll y h = look h S.empty
-             EQ -> S.lcons x $ look i $ look xs rest
-             GT -> rest
- 
--minView :: (Ord a, Monad m) => Heap a -> m (a, Heap a)
-+minView :: (Ord a, Fail.MonadFail m) => Heap a -> m (a, Heap a)
- minView E = fail "LazyPairingHeap.minView: empty heap"
- minView (H1 x xs) = return (x,xs)
- minView (H2 x h xs) = return (x,union h xs)
-@@ -369,7 +370,7 @@ minElem E = error "LazyPairingHeap.minElem: empty heap"
- minElem (H1 x _) = x
- minElem (H2 x _ _) = x
- 
--maxView :: (Ord a, Monad m) => Heap a -> m (a, Heap a)
-+maxView :: (Ord a, Fail.MonadFail m) => Heap a -> m (a, Heap a)
- maxView E = fail "LazyPairingHeap.maxView: empty heap"
- maxView xs = return (y,xs')
-   where (xs', y) = maxView' xs
-@@ -474,7 +475,7 @@ deleteMax = deleteMaxUsingMaxView
- lookup :: Ord a => a -> Heap a -> a
- lookup = lookupUsingLookupAll
- 
--lookupM :: (Ord a, Monad m) => a -> Heap a -> m a
-+lookupM :: (Ord a, Fail.MonadFail m) => a -> Heap a -> m a
- lookupM = lookupMUsingLookupAll
- 
- lookupWithDefault :: Ord a => a -> a -> Heap a -> a
-diff --git a/src/Data/Edison/Coll/LeftistHeap.hs b/src/Data/Edison/Coll/LeftistHeap.hs
-index 751394b..10ccf5a 100644
---- a/src/Data/Edison/Coll/LeftistHeap.hs
-+++ b/src/Data/Edison/Coll/LeftistHeap.hs
-@@ -47,6 +47,7 @@ import Data.Edison.Coll.Defaults
- import Data.Monoid
- import Data.Semigroup as SG
- import Control.Monad
-+import qualified Control.Monad.Fail as Fail
- import Test.QuickCheck
- 
- moduleName :: String
-@@ -173,7 +174,7 @@ toSeq h = tol h S.empty
-   where tol E rest = rest
-         tol (L _ x a b) rest = S.lcons x (tol b (tol a rest))
- 
--lookupM :: (Ord a, Monad m) => a -> Heap a -> m a
-+lookupM :: (Ord a, Fail.MonadFail m) => a -> Heap a -> m a
- lookupM _ E = fail "LeftistHeap.lookupM: XXX"
- lookupM x (L _ y a b) =
-   case compare x y of
-@@ -299,7 +300,7 @@ partitionLT_GT y h = (h', C.unionList hs)
-                       (b', hs'') = collect b hs'
-                   in (node x a' b', hs'')
- 
--minView :: (Ord a, Monad m) => Heap a -> m (a, Heap a)
-+minView :: (Ord a, Fail.MonadFail m) => Heap a -> m (a, Heap a)
- minView E = fail "LeftistHeap.minView: empty collection"
- minView (L _ x a b) = return (x, union a b)
- 
-@@ -307,7 +308,7 @@ minElem :: Ord a => Heap a -> a
- minElem E = error "LeftistHeap.minElem: empty collection"
- minElem (L _ x _ _) = x
- 
--maxView :: (Ord a, Monad m) => Heap a -> m (a, Heap a)
-+maxView :: (Ord a, Fail.MonadFail m) => Heap a -> m (a, Heap a)
- maxView E = fail "LeftistHeap.maxView: empty collection"
- maxView (L _ x E _) = return (x, E)
- maxView (L _ x a E) = return (y, L 1 x a' E)
-diff --git a/src/Data/Edison/Coll/MinHeap.hs b/src/Data/Edison/Coll/MinHeap.hs
-index ba38960..94e2f1b 100644
---- a/src/Data/Edison/Coll/MinHeap.hs
-+++ b/src/Data/Edison/Coll/MinHeap.hs
-@@ -46,6 +46,7 @@ import Data.Edison.Seq.Defaults (tokenMatch,maybeParens)
- import Data.Monoid
- import qualified Data.Semigroup as SG
- import Control.Monad
-+import qualified Control.Monad.Fail as Fail
- import Test.QuickCheck
- 
- data Min h a = E | M a h  deriving (Eq)
-@@ -75,7 +76,7 @@ strict    :: (C.CollX h a,Ord a) => Min h a -> Min h a
- 
- toSeq     :: (C.Coll h a,S.Sequence s) => Min h a -> s a
- lookup    :: (C.Coll h a,Ord a) => a -> Min h a -> a
--lookupM   :: (C.Coll h a,Ord a,Monad m) => a -> Min h a -> m a
-+lookupM   :: (C.Coll h a, Ord a, Fail.MonadFail m) => a -> Min h a -> m a
- lookupAll :: (C.Coll h a,Ord a,S.Sequence s) => a -> Min h a -> s a
- lookupWithDefault :: (C.Coll h a,Ord a) => a -> a -> Min h a -> a
- fold      :: (C.Coll h a) => (a -> b -> b) -> b -> Min h a -> b
-@@ -100,9 +101,9 @@ partitionLT_GE :: (C.OrdColl h a,Ord a) => a -> Min h a -> (Min h a, Min h a)
- partitionLE_GT :: (C.OrdColl h a,Ord a) => a -> Min h a -> (Min h a, Min h a)
- partitionLT_GT :: (C.OrdColl h a,Ord a) => a -> Min h a -> (Min h a, Min h a)
- 
--minView :: (C.OrdColl h a,Ord a,Monad m) => Min h a -> m (a, Min h a)
-+minView :: (C.OrdColl h a, Ord a, Fail.MonadFail m) => Min h a -> m (a, Min h a)
- minElem :: (C.OrdColl h a,Ord a) => Min h a -> a
--maxView :: (C.OrdColl h a,Ord a,Monad m) => Min h a -> m (a, Min h a)
-+maxView :: (C.OrdColl h a, Ord a, Fail.MonadFail m) => Min h a -> m (a, Min h a)
- maxElem :: (C.OrdColl h a,Ord a) => Min h a -> a
- foldr :: (C.OrdColl h a,Ord a) => (a -> b -> b) -> b -> Min h a -> b
- foldl :: (C.OrdColl h a,Ord a) => (b -> a -> b) -> b -> Min h a -> b
-diff --git a/src/Data/Edison/Coll/SkewHeap.hs b/src/Data/Edison/Coll/SkewHeap.hs
-index 1a05ebe..e55ba58 100644
---- a/src/Data/Edison/Coll/SkewHeap.hs
-+++ b/src/Data/Edison/Coll/SkewHeap.hs
-@@ -47,6 +47,7 @@ import Data.Edison.Coll.Defaults
- import Data.Monoid
- import Data.Semigroup as SG
- import Control.Monad
-+import qualified Control.Monad.Fail as Fail
- 
- import Test.QuickCheck
- 
-@@ -142,7 +143,7 @@ toSeq h = tol h S.empty
-   where tol E rest = rest
-         tol (T x a b) rest = S.lcons x (tol b (tol a rest))
- 
--lookupM :: (Ord a, Monad m) => a -> Heap a -> m a
-+lookupM :: (Ord a, Fail.MonadFail m) => a -> Heap a -> m a
- lookupM _ E = fail "SkewHeap.lookupM: XXX"
- lookupM x (T y a b) =
-   case compare x y of
-@@ -267,7 +268,7 @@ partitionLT_GT y h = (h', C.unionList hs)
-                       (b', hs'') = collect b hs'
-                   in (T x a' b', hs'')
- 
--minView :: (Ord a, Monad m) => Heap a -> m (a, Heap a)
-+minView :: (Ord a, Fail.MonadFail m) => Heap a -> m (a, Heap a)
- minView E = fail "SkewHeap.minView: empty heap"
- minView (T x a b) = return (x, union a b)
- 
-@@ -275,7 +276,7 @@ minElem :: Ord a => Heap a -> a
- minElem E = error "SkewHeap.minElem: empty collection"
- minElem (T x _ _) = x
- 
--maxView :: (Ord a, Monad m) => Heap a -> m (a, Heap a)
-+maxView :: (Ord a, Fail.MonadFail m) => Heap a -> m (a, Heap a)
- maxView E = fail "SkewHeap.maxView: empty heap"
- maxView (T x E E) = return (x, E)
- maxView (T x a E) = return (y, T x a' E)
-diff --git a/src/Data/Edison/Coll/SplayHeap.hs b/src/Data/Edison/Coll/SplayHeap.hs
-index 4e3b061..6c950b7 100644
---- a/src/Data/Edison/Coll/SplayHeap.hs
-+++ b/src/Data/Edison/Coll/SplayHeap.hs
-@@ -50,6 +50,7 @@ import Data.Edison.Coll.Defaults
- import Data.Monoid
- import Data.Semigroup as SG
- import Control.Monad
-+import qualified Control.Monad.Fail as Fail
- import Test.QuickCheck
- 
- moduleName :: String
-@@ -93,7 +94,7 @@ strict    :: Heap a -> Heap a
- 
- toSeq     :: (Ord a, S.Sequence s) => Heap a -> s a
- lookup    :: Ord a => a -> Heap a -> a
--lookupM   :: (Ord a,Monad m) => a -> Heap a -> m a
-+lookupM   :: (Ord a, Fail.MonadFail m) => a -> Heap a -> m a
- lookupAll :: (Ord a,S.Sequence s) => a -> Heap a -> s a
- lookupWithDefault :: Ord a => a -> a -> Heap a -> a
- fold      :: Ord a => (a -> b -> b) -> b -> Heap a -> b
-@@ -118,9 +119,9 @@ partitionLT_GE   :: Ord a => a -> Heap a -> (Heap a, Heap a)
- partitionLE_GT   :: Ord a => a -> Heap a -> (Heap a, Heap a)
- partitionLT_GT   :: Ord a => a -> Heap a -> (Heap a, Heap a)
- 
--minView  :: (Ord a,Monad m) => Heap a -> m (a, Heap a)
-+minView  :: (Ord a, Fail.MonadFail m) => Heap a -> m (a, Heap a)
- minElem  :: Ord a => Heap a -> a
--maxView  :: (Ord a,Monad m) => Heap a -> m (a, Heap a)
-+maxView  :: (Ord a, Fail.MonadFail m) => Heap a -> m (a, Heap a)
- maxElem  :: Ord a => Heap a -> a
- foldr    :: Ord a => (a -> b -> b) -> b -> Heap a -> b
- foldl    :: Ord a => (b -> a -> b) -> b -> Heap a -> b
-diff --git a/src/Data/Edison/Coll/StandardSet.hs b/src/Data/Edison/Coll/StandardSet.hs
-index fcaf715..56df4bf 100644
---- a/src/Data/Edison/Coll/StandardSet.hs
-+++ b/src/Data/Edison/Coll/StandardSet.hs
-@@ -43,6 +43,7 @@ module Data.Edison.Coll.StandardSet (
- 
- import Prelude hiding (null,foldr,foldl,foldr1,foldl1,lookup,filter)
- import qualified Prelude
-+import qualified Control.Monad.Fail as Fail
- import qualified Data.List
- 
- import qualified Data.Edison.Coll as C
-@@ -73,7 +74,7 @@ strict     :: Ord a => Set a -> Set a
- 
- toSeq      :: (Ord a,S.Sequence seq) => Set a -> seq a
- lookup     :: Ord a => a -> Set a -> a
--lookupM    :: (Ord a,Monad m) => a -> Set a -> m a
-+lookupM    :: (Ord a, Monad m, Fail.MonadFail m) => a -> Set a -> m a
- lookupAll  :: (Ord a,S.Sequence seq) => a -> Set a -> seq a
- lookupWithDefault :: Ord a => a -> a -> Set a  -> a
- fold       :: (a -> b -> b) -> b -> Set a -> b
-@@ -98,9 +99,9 @@ partitionLT_GE   :: Ord a => a -> Set a -> (Set a, Set a)
- partitionLE_GT   :: Ord a => a -> Set a -> (Set a, Set a)
- partitionLT_GT   :: Ord a => a -> Set a -> (Set a, Set a)
- 
--minView       :: (Ord a,Monad m) => Set a -> m (a, Set a)
-+minView       :: (Ord a, Monad m, Fail.MonadFail m) => Set a -> m (a, Set a)
- minElem       :: Set a -> a
--maxView       :: (Ord a,Monad m) => Set a -> m (a, Set a)
-+maxView       :: (Ord a, Monad m, Fail.MonadFail m) => Set a -> m (a, Set a)
- maxElem       :: Set a -> a
- foldr         :: (a -> b -> b) -> b -> Set a -> b
- foldl         :: (b -> a -> b) -> b -> Set a -> b
-diff --git a/src/Data/Edison/Coll/UnbalancedSet.hs b/src/Data/Edison/Coll/UnbalancedSet.hs
-index 03cb856..d7975d0 100644
---- a/src/Data/Edison/Coll/UnbalancedSet.hs
-+++ b/src/Data/Edison/Coll/UnbalancedSet.hs
-@@ -43,6 +43,7 @@ module Data.Edison.Coll.UnbalancedSet (
- 
- import Prelude hiding (null,foldr,foldl,foldr1,foldl1,lookup,filter)
- import qualified Prelude
-+import qualified Control.Monad.Fail as Fail
- import qualified Data.Edison.Coll as C
- import qualified Data.Edison.Seq as S
- import Data.Edison.Coll.Defaults
-@@ -70,7 +71,7 @@ strict     :: Set a -> Set a
- 
- toSeq      :: (Ord a,S.Sequence seq) => Set a -> seq a
- lookup     :: Ord a => a -> Set a -> a
--lookupM    :: (Ord a,Monad m) => a -> Set a -> m a
-+lookupM    :: (Ord a, Fail.MonadFail m) => a -> Set a -> m a
- lookupAll  :: (Ord a,S.Sequence seq) => a -> Set a -> seq a
- lookupWithDefault :: Ord a => a -> a -> Set a -> a
- fold       :: (a -> b -> b) -> b -> Set a -> b
-@@ -95,9 +96,9 @@ partitionLT_GE   :: Ord a => a -> Set a -> (Set a, Set a)
- partitionLE_GT   :: Ord a => a -> Set a -> (Set a, Set a)
- partitionLT_GT   :: Ord a => a -> Set a -> (Set a, Set a)
- 
--minView       :: (Monad m) => Set a -> m (a, Set a)
-+minView       :: (Fail.MonadFail m) => Set a -> m (a, Set a)
- minElem       :: Set a -> a
--maxView       :: (Monad m) => Set a -> m (a, Set a)
-+maxView       :: (Fail.MonadFail m) => Set a -> m (a, Set a)
- maxElem       :: Set a -> a
- foldr         :: (a -> b -> b) -> b -> Set a -> b
- foldl         :: (b -> a -> b) -> b -> Set a -> b
-diff --git a/src/Data/Edison/Concrete/FingerTree.hs b/src/Data/Edison/Concrete/FingerTree.hs
-index 47f766c..c6a2ac0 100644
---- a/src/Data/Edison/Concrete/FingerTree.hs
-+++ b/src/Data/Edison/Concrete/FingerTree.hs
-@@ -81,6 +81,7 @@ import Test.QuickCheck
- import Data.Edison.Prelude
- 
- import Control.Monad (liftM2, liftM3, liftM4)
-+import qualified Control.Monad.Fail as Fail
- 
- 
- infixr 5 `lcons`
-@@ -334,7 +335,7 @@ null Empty = True
- null _ = False
- 
- -- | /O(1)/. Analyse the left end of a sequence.
--lview :: (Measured v a, Monad m) => FingerTree v a -> m (a,FingerTree v a)
-+lview :: (Measured v a, Fail.MonadFail m) => FingerTree v a -> m (a,FingerTree v a)
- lview Empty                 =  fail "FingerTree.lview: empty tree"
- lview (Single x)            =  return (x, Empty)
- lview (Deep _ (One x) m sf) =  return . (,) x $
-@@ -357,7 +358,7 @@ ltailDigit (Four _ b c d) = Three b c d
- ltailDigit _ = error "FingerTree.ltailDigit: bug!"
- 
- -- | /O(1)/. Analyse the right end of a sequence.
--rview :: (Measured v a, Monad m) => FingerTree v a -> m (a, FingerTree v a)
-+rview :: (Measured v a, Fail.MonadFail m) => FingerTree v a -> m (a, FingerTree v a)
- rview Empty                  = fail "FingerTree.rview: empty tree"
- rview (Single x)             = return (x, Empty)
- rview (Deep _ pr m (One x))  = return . (,) x $
-diff --git a/src/Data/Edison/Seq/BankersQueue.hs b/src/Data/Edison/Seq/BankersQueue.hs
-index 6dac746..0ab24c9 100644
---- a/src/Data/Edison/Seq/BankersQueue.hs
-+++ b/src/Data/Edison/Seq/BankersQueue.hs
-@@ -51,11 +51,13 @@ import Prelude hiding (concat,reverse,map,concatMap,foldr,foldl,foldr1,foldl1,
- 
- import qualified Control.Applicative as App
- 
-+import Data.Edison.Prelude ( runFail_ )
- import qualified Data.Edison.Seq as S ( Sequence(..) )
- import Data.Edison.Seq.Defaults
- import qualified Data.Edison.Seq.ListSeq as L
- import Data.Monoid
- import Data.Semigroup as SG
-+import qualified Control.Monad.Fail as Fail
- import Control.Monad.Identity
- import Test.QuickCheck
- 
-@@ -66,16 +68,16 @@ singleton      :: a -> Seq a
- lcons          :: a -> Seq a -> Seq a
- rcons          :: a -> Seq a -> Seq a
- append         :: Seq a -> Seq a -> Seq a
--lview          :: (Monad m) => Seq a -> m (a, Seq a)
-+lview          :: (Fail.MonadFail m) => Seq a -> m (a, Seq a)
- lhead          :: Seq a -> a
--lheadM         :: (Monad m) => Seq a -> m a
-+lheadM         :: (Fail.MonadFail m) => Seq a -> m a
- ltail          :: Seq a -> Seq a
--ltailM         :: (Monad m) => Seq a -> m (Seq a)
--rview          :: (Monad m) => Seq a -> m (a, Seq a)
-+ltailM         :: (Fail.MonadFail m) => Seq a -> m (Seq a)
-+rview          :: (Fail.MonadFail m) => Seq a -> m (a, Seq a)
- rhead          :: Seq a -> a
--rheadM         :: (Monad m) => Seq a -> m a
-+rheadM         :: (Fail.MonadFail m) => Seq a -> m a
- rtail          :: Seq a -> Seq a
--rtailM         :: (Monad m) => Seq a -> m (Seq a)
-+rtailM         :: (Fail.MonadFail m) => Seq a -> m (Seq a)
- null           :: Seq a -> Bool
- size           :: Seq a -> Int
- concat         :: Seq (Seq a) -> Seq a
-@@ -106,7 +108,7 @@ reduce1'       :: (a -> a -> a) -> Seq a -> a
- copy           :: Int -> a -> Seq a
- inBounds       :: Int -> Seq a -> Bool
- lookup         :: Int -> Seq a -> a
--lookupM        :: (Monad m) => Int -> Seq a -> m a
-+lookupM        :: (Fail.MonadFail m) => Int -> Seq a -> m a
- lookupWithDefault :: a -> Int -> Seq a -> a
- update         :: Int -> a -> Seq a -> Seq a
- adjust         :: (a -> a) -> Int -> Seq a -> Seq a
-@@ -263,7 +265,7 @@ copy n x
- 
- -- reduce1: given sizes could do more effective job of dividing evenly!
- 
--lookup idx q = runIdentity (lookupM idx q)
-+lookup idx q = runFail_ (lookupM idx q)
- 
- lookupM idx (Q i xs ys j)
-   | idx < i   = L.lookupM idx xs
-diff --git a/src/Data/Edison/Seq/BinaryRandList.hs b/src/Data/Edison/Seq/BinaryRandList.hs
-index b01b9b8..e772b65 100644
---- a/src/Data/Edison/Seq/BinaryRandList.hs
-+++ b/src/Data/Edison/Seq/BinaryRandList.hs
-@@ -55,14 +55,15 @@ import Prelude hiding (concat,reverse,map,concatMap,foldr,foldl,foldr1,foldl1,
-                        zip,zip3,zipWith,zipWith3,unzip,unzip3,null)
- 
- import qualified Control.Applicative as App
--import Control.Monad.Identity
- import Data.Maybe
- 
-+import Data.Edison.Prelude ( runFail_ )
- import qualified Data.Edison.Seq as S ( Sequence(..) )
- import Data.Edison.Seq.Defaults
- import Data.Monoid
- import Data.Semigroup as SG
- import Control.Monad
-+import qualified Control.Monad.Fail as Fail
- import Test.QuickCheck
- 
- -- signatures for exported functions
-@@ -72,16 +73,16 @@ singleton      :: a -> Seq a
- lcons          :: a -> Seq a -> Seq a
- rcons          :: a -> Seq a -> Seq a
- append         :: Seq a -> Seq a -> Seq a
--lview          :: (Monad m) => Seq a -> m (a, Seq a)
-+lview          :: (Fail.MonadFail m) => Seq a -> m (a, Seq a)
- lhead          :: Seq a -> a
--lheadM         :: (Monad m) => Seq a -> m a
-+lheadM         :: (Fail.MonadFail m) => Seq a -> m a
- ltail          :: Seq a -> Seq a
--ltailM         :: (Monad m) => Seq a -> m (Seq a)
--rview          :: (Monad m) => Seq a -> m (a, Seq a)
-+ltailM         :: (Fail.MonadFail m) => Seq a -> m (Seq a)
-+rview          :: (Fail.MonadFail m) => Seq a -> m (a, Seq a)
- rhead          :: Seq a -> a
--rheadM         :: (Monad m) => Seq a -> m a
-+rheadM         :: (Fail.MonadFail m) => Seq a -> m a
- rtail          :: Seq a -> Seq a
--rtailM         :: (Monad m) => Seq a -> m (Seq a)
-+rtailM         :: (Fail.MonadFail m) => Seq a -> m (Seq a)
- null           :: Seq a -> Bool
- size           :: Seq a -> Int
- concat         :: Seq (Seq a) -> Seq a
-@@ -112,7 +113,7 @@ reduce1'       :: (a -> a -> a) -> Seq a -> a
- copy           :: Int -> a -> Seq a
- inBounds       :: Int -> Seq a -> Bool
- lookup         :: Int -> Seq a -> a
--lookupM        :: (Monad m) => Int -> Seq a -> m a
-+lookupM        :: (Fail.MonadFail m) => Int -> Seq a -> m a
- lookupWithDefault :: a -> Int -> Seq a -> a
- update         :: Int -> a -> Seq a -> Seq a
- adjust         :: (a -> a) -> Int -> Seq a -> Seq a
-@@ -267,7 +268,7 @@ inBounds i xs = (i >= 0) && inb xs i
-         inb (Even ps) i = inb ps (half i)
-         inb (Odd _ ps) i = (i == 0) || inb ps (half (i-1))
- 
--lookup i xs = runIdentity (lookupM i xs)
-+lookup i xs = runFail_ (lookupM i xs)
- 
- lookupM i xs
-     | i < 0     = fail "BinaryRandList.lookup: bad subscript"
-diff --git a/src/Data/Edison/Seq/BraunSeq.hs b/src/Data/Edison/Seq/BraunSeq.hs
-index 7f6f33b..11236e3 100644
---- a/src/Data/Edison/Seq/BraunSeq.hs
-+++ b/src/Data/Edison/Seq/BraunSeq.hs
-@@ -72,6 +72,7 @@ import Prelude hiding (concat,reverse,map,concatMap,foldr,foldl,foldr1,foldl1,
-                        zip,zip3,zipWith,zipWith3,unzip,unzip3,null)
- 
- import qualified Control.Applicative as App
-+import qualified Control.Monad.Fail as Fail
- import Control.Monad.Identity
- import Data.Maybe
- import Data.Monoid
-@@ -79,6 +80,7 @@ import Data.Semigroup as SG
- import Test.QuickCheck
- 
- 
-+import Data.Edison.Prelude ( runFail_ )
- import qualified Data.Edison.Seq as S ( Sequence(..) )
- import Data.Edison.Seq.Defaults
- import qualified Data.Edison.Seq.ListSeq as L
-@@ -91,16 +93,16 @@ singleton      :: a -> Seq a
- lcons          :: a -> Seq a -> Seq a
- rcons          :: a -> Seq a -> Seq a
- append         :: Seq a -> Seq a -> Seq a
--lview          :: (Monad m) => Seq a -> m (a, Seq a)
-+lview          :: (Fail.MonadFail m) => Seq a -> m (a, Seq a)
- lhead          :: Seq a -> a
--lheadM         :: (Monad m) => Seq a -> m a
-+lheadM         :: (Fail.MonadFail m) => Seq a -> m a
- ltail          :: Seq a -> Seq a
--ltailM         :: (Monad m) => Seq a -> m (Seq a)
--rview          :: (Monad m) => Seq a -> m (a, Seq a)
-+ltailM         :: (Fail.MonadFail m) => Seq a -> m (Seq a)
-+rview          :: (Fail.MonadFail m) => Seq a -> m (a, Seq a)
- rhead          :: Seq a -> a
--rheadM         :: (Monad m) => Seq a -> m a
-+rheadM         :: (Fail.MonadFail m) => Seq a -> m a
- rtail          :: Seq a -> Seq a
--rtailM         :: (Monad m) => Seq a -> m (Seq a)
-+rtailM         :: (Fail.MonadFail m) => Seq a -> m (Seq a)
- null           :: Seq a -> Bool
- size           :: Seq a -> Int
- concat         :: Seq (Seq a) -> Seq a
-@@ -131,7 +133,7 @@ reduce1'       :: (a -> a -> a) -> Seq a -> a
- copy           :: Int -> a -> Seq a
- inBounds       :: Int -> Seq a -> Bool
- lookup         :: Int -> Seq a -> a
--lookupM        :: (Monad m) => Int -> Seq a -> m a
-+lookupM        :: (Fail.MonadFail m) => Int -> Seq a -> m a
- lookupWithDefault :: a -> Int -> Seq a -> a
- update         :: Int -> a -> Seq a -> Seq a
- adjust         :: (a -> a) -> Int -> Seq a -> Seq a
-@@ -344,7 +346,7 @@ inBounds i xs = (i >= 0) && inb xs i
-           | i == 0    = True
-           | otherwise = inb b (half i - 1)
- 
--lookup i xs = runIdentity (lookupM i xs)
-+lookup i xs = runFail_ (lookupM i xs)
- 
- lookupM i xs
-   | i < 0     = fail "BraunSeq.lookupM: bad subscript"
-diff --git a/src/Data/Edison/Seq/Defaults.hs b/src/Data/Edison/Seq/Defaults.hs
-index ed593dc..eae6a09 100644
---- a/src/Data/Edison/Seq/Defaults.hs
-+++ b/src/Data/Edison/Seq/Defaults.hs
-@@ -17,9 +17,11 @@ import Prelude hiding (concat,reverse,map,concatMap,foldr,foldl,foldr1,foldl1,
-                        filter,takeWhile,dropWhile,lookup,take,drop,splitAt,
-                        zip,zip3,zipWith,zipWith3,unzip,unzip3,null)
- 
-+import qualified Control.Monad.Fail as Fail
- import Control.Monad.Identity
- import Data.Char (isSpace)
- 
-+import Data.Edison.Prelude ( runFail_ )
- import Data.Edison.Seq
- import qualified Data.Edison.Seq.ListSeq as L
- 
-@@ -33,7 +35,7 @@ appendUsingFoldr :: Sequence s => s a -> s a -> s a
- appendUsingFoldr s t | null t = s
-                             | otherwise = foldr lcons t s
- 
--rviewDefault :: (Monad m, Sequence s) => s a -> m (a, s a)
-+rviewDefault :: (Fail.MonadFail m, Sequence s) => s a -> m (a, s a)
- rviewDefault xs
-   | null xs   = fail $ instanceName xs ++ ".rview: empty sequence"
-   | otherwise = return (rhead xs, rtail xs)
-@@ -49,7 +51,7 @@ rtailUsingLview xs =
-             Nothing      -> empty
-             Just (y, ys) -> lcons x (rt y ys)
- 
--rtailMUsingLview :: (Monad m,Sequence s) => s a -> m (s a)
-+rtailMUsingLview :: (Fail.MonadFail m, Sequence s) => s a -> m (s a)
- rtailMUsingLview xs =
-     case lview xs of
-       Nothing      -> fail $ instanceName xs ++ ".rtailM: empty sequence"
-@@ -200,7 +202,7 @@ inBoundsUsingSize :: Sequence s => Int -> s a -> Bool
- inBoundsUsingSize i s = i >= 0 && i < size s
- 
- lookupUsingLookupM :: Sequence s => Int -> s a -> a
--lookupUsingLookupM i s = runIdentity (lookupM i s)
-+lookupUsingLookupM i s = runFail_ (lookupM i s)
- 
- lookupUsingDrop :: Sequence s => Int -> s a -> a
- lookupUsingDrop i s
-@@ -220,7 +222,7 @@ lookupWithDefaultUsingDrop d i s
-   | otherwise = lhead s'
-   where s' = drop i s
- 
--lookupMUsingDrop :: (Monad m, Sequence s) => Int -> s a -> m a
-+lookupMUsingDrop :: (Fail.MonadFail m, Sequence s) => Int -> s a -> m a
- lookupMUsingDrop i s
-   -- XXX better error message!
-   | i < 0 || null s' = fail $ instanceName s
-diff --git a/src/Data/Edison/Seq/FingerSeq.hs b/src/Data/Edison/Seq/FingerSeq.hs
-index c74c70b..a34254c 100644
---- a/src/Data/Edison/Seq/FingerSeq.hs
-+++ b/src/Data/Edison/Seq/FingerSeq.hs
-@@ -37,9 +37,10 @@ import Prelude hiding (concat,reverse,map,concatMap,foldr,foldl,foldr1,foldl1,
-                        zip,zip3,zipWith,zipWith3,unzip,unzip3,null)
- 
- import qualified Control.Applicative as App
--import Data.Edison.Prelude (measure, Measured())
-+import Data.Edison.Prelude (measure, Measured(), runFail_)
- import qualified Data.Edison.Seq as S
- import Data.Edison.Seq.Defaults
-+import qualified Control.Monad.Fail as Fail
- import Control.Monad.Identity
- import Data.Monoid
- import Data.Semigroup as SG
-@@ -87,16 +88,16 @@ singleton      :: a -> Seq a
- lcons          :: a -> Seq a -> Seq a
- rcons          :: a -> Seq a -> Seq a
- append         :: Seq a -> Seq a -> Seq a
--lview          :: (Monad m) => Seq a -> m (a, Seq a)
-+lview          :: (Fail.MonadFail m) => Seq a -> m (a, Seq a)
- lhead          :: Seq a -> a
--lheadM         :: (Monad m) => Seq a -> m a
-+lheadM         :: (Fail.MonadFail m) => Seq a -> m a
- ltail          :: Seq a -> Seq a
--ltailM         :: (Monad m) => Seq a -> m (Seq a)
--rview          :: (Monad m) => Seq a -> m (a, Seq a)
-+ltailM         :: (Fail.MonadFail m) => Seq a -> m (Seq a)
-+rview          :: (Fail.MonadFail m) => Seq a -> m (a, Seq a)
- rhead          :: Seq a -> a
--rheadM         :: (Monad m) => Seq a -> m a
-+rheadM         :: (Fail.MonadFail m) => Seq a -> m a
- rtail          :: Seq a -> Seq a
--rtailM         :: (Monad m) => Seq a -> m (Seq a)
-+rtailM         :: (Fail.MonadFail m) => Seq a -> m (Seq a)
- null           :: Seq a -> Bool
- size           :: Seq a -> Int
- concat         :: Seq (Seq a) -> Seq a
-@@ -127,7 +128,7 @@ reduce1'       :: (a -> a -> a) -> Seq a -> a
- copy           :: Int -> a -> Seq a
- inBounds       :: Int -> Seq a -> Bool
- lookup         :: Int -> Seq a -> a
--lookupM        :: (Monad m) => Int -> Seq a -> m a
-+lookupM        :: (Fail.MonadFail m) => Int -> Seq a -> m a
- lookupWithDefault :: a -> Int -> Seq a -> a
- update         :: Int -> a -> Seq a -> Seq a
- adjust         :: (a -> a) -> Int -> Seq a -> Seq a
-@@ -206,10 +207,10 @@ lheadM xs = lview xs >>= return . fst
- ltailM xs = lview xs >>= return . snd
- rheadM xs = rview xs >>= return . fst
- rtailM xs = rview xs >>= return . snd
--lhead = runIdentity . lheadM
--ltail = runIdentity . ltailM
--rhead = runIdentity . rheadM
--rtail = runIdentity . rtailM
-+lhead = runFail_ . lheadM
-+ltail = runFail_ . ltailM
-+rhead = runFail_ . rheadM
-+rtail = runFail_ . rtailM
- 
- fold     = foldr
- fold'    = foldr'
-diff --git a/src/Data/Edison/Seq/JoinList.hs b/src/Data/Edison/Seq/JoinList.hs
-index 6922023..05855ba 100644
---- a/src/Data/Edison/Seq/JoinList.hs
-+++ b/src/Data/Edison/Seq/JoinList.hs
-@@ -57,6 +57,7 @@ import qualified Control.Applicative as App
- 
- import Data.Edison.Seq.Defaults
- import Control.Monad
-+import qualified Control.Monad.Fail as Fail
- import Data.Monoid
- import Data.Semigroup as SG
- import Test.QuickCheck
-@@ -68,16 +69,16 @@ singleton      :: a -> Seq a
- lcons          :: a -> Seq a -> Seq a
- rcons          :: a -> Seq a -> Seq a
- append         :: Seq a -> Seq a -> Seq a
--lview          :: (Monad m) => Seq a -> m (a, Seq a)
-+lview          :: (Fail.MonadFail m) => Seq a -> m (a, Seq a)
- lhead          :: Seq a -> a
--lheadM         :: (Monad m) => Seq a -> m a
-+lheadM         :: (Fail.MonadFail m) => Seq a -> m a
- ltail          :: Seq a -> Seq a
--ltailM         :: (Monad m) => Seq a -> m (Seq a)
--rview          :: (Monad m) => Seq a -> m (a, Seq a)
-+ltailM         :: (Fail.MonadFail m) => Seq a -> m (Seq a)
-+rview          :: (Fail.MonadFail m) => Seq a -> m (a, Seq a)
- rhead          :: Seq a -> a
--rheadM         :: (Monad m) => Seq a -> m a
-+rheadM         :: (Fail.MonadFail m) => Seq a -> m a
- rtail          :: Seq a -> Seq a
--rtailM         :: (Monad m) => Seq a -> m (Seq a)
-+rtailM         :: (Fail.MonadFail m) => Seq a -> m (Seq a)
- null           :: Seq a -> Bool
- size           :: Seq a -> Int
- concat         :: Seq (Seq a) -> Seq a
-@@ -108,7 +109,7 @@ reduce1'       :: (a -> a -> a) -> Seq a -> a
- copy           :: Int -> a -> Seq a
- inBounds       :: Int -> Seq a -> Bool
- lookup         :: Int -> Seq a -> a
--lookupM        :: (Monad m) => Int -> Seq a -> m a
-+lookupM        :: (Fail.MonadFail m) => Int -> Seq a -> m a
- lookupWithDefault :: a -> Int -> Seq a -> a
- update         :: Int -> a -> Seq a -> Seq a
- adjust         :: (a -> a) -> Int -> Seq a -> Seq a
-diff --git a/src/Data/Edison/Seq/MyersStack.hs b/src/Data/Edison/Seq/MyersStack.hs
-index 30eb197..eca46a5 100644
---- a/src/Data/Edison/Seq/MyersStack.hs
-+++ b/src/Data/Edison/Seq/MyersStack.hs
-@@ -49,8 +49,10 @@ import Prelude hiding (concat,reverse,map,concatMap,foldr,foldl,foldr1,foldl1,
-                        zip,zip3,zipWith,zipWith3,unzip,unzip3,null)
- 
- import qualified Control.Applicative as App
-+import Data.Edison.Prelude ( runFail_ )
- import qualified Data.Edison.Seq as S ( Sequence(..) )
- import Data.Edison.Seq.Defaults
-+import qualified Control.Monad.Fail as Fail
- import Control.Monad.Identity
- import Data.Monoid
- import Data.Semigroup as SG
-@@ -63,16 +65,16 @@ singleton      :: a -> Seq a
- lcons          :: a -> Seq a -> Seq a
- rcons          :: a -> Seq a -> Seq a
- append         :: Seq a -> Seq a -> Seq a
--lview          :: (Monad m) => Seq a -> m (a, Seq a)
-+lview          :: (Fail.MonadFail m) => Seq a -> m (a, Seq a)
- lhead          :: Seq a -> a
--lheadM         :: (Monad m) => Seq a -> m a
-+lheadM         :: (Fail.MonadFail m) => Seq a -> m a
- ltail          :: Seq a -> Seq a
--ltailM         :: (Monad m) => Seq a -> m (Seq a)
--rview          :: (Monad m) => Seq a -> m (a, Seq a)
-+ltailM         :: (Fail.MonadFail m) => Seq a -> m (Seq a)
-+rview          :: (Fail.MonadFail m) => Seq a -> m (a, Seq a)
- rhead          :: Seq a -> a
--rheadM         :: (Monad m) => Seq a -> m a
-+rheadM         :: (Fail.MonadFail m) => Seq a -> m a
- rtail          :: Seq a -> Seq a
--rtailM         :: (Monad m) => Seq a -> m (Seq a)
-+rtailM         :: (Fail.MonadFail m) => Seq a -> m (Seq a)
- null           :: Seq a -> Bool
- size           :: Seq a -> Int
- concat         :: Seq (Seq a) -> Seq a
-@@ -103,7 +105,7 @@ reduce1'       :: (a -> a -> a) -> Seq a -> a
- copy           :: Int -> a -> Seq a
- inBounds       :: Int -> Seq a -> Bool
- lookup         :: Int -> Seq a -> a
--lookupM        :: (Monad m) => Int -> Seq a -> m a
-+lookupM        :: (Fail.MonadFail m) => Int -> Seq a -> m a
- lookupWithDefault :: a -> Int -> Seq a -> a
- update         :: Int -> a -> Seq a -> Seq a
- adjust         :: (a -> a) -> Int -> Seq a -> Seq a
-@@ -246,7 +248,7 @@ inBounds i xs = inb xs i
-           | i < j     = (i >= 0)
-           | otherwise = inb xs' (i - j)
- 
--lookup i xs = runIdentity (lookupM i xs)
-+lookup i xs = runFail_ (lookupM i xs)
- 
- lookupM i xs = look xs i
-   where look E _ = fail "MyersStack.lookup: bad subscript"
-diff --git a/src/Data/Edison/Seq/RandList.hs b/src/Data/Edison/Seq/RandList.hs
-index 8fe97bd..8d2d38b 100644
---- a/src/Data/Edison/Seq/RandList.hs
-+++ b/src/Data/Edison/Seq/RandList.hs
-@@ -55,8 +55,10 @@ import Prelude hiding (concat,reverse,map,concatMap,foldr,foldl,foldr1,foldl1,
- 
- import qualified Control.Applicative as App
- 
-+import Data.Edison.Prelude ( runFail_ )
- import qualified Data.Edison.Seq as S( Sequence(..) )
- import Data.Edison.Seq.Defaults
-+import qualified Control.Monad.Fail as Fail
- import Control.Monad.Identity
- import Data.Monoid
- import Data.Semigroup as SG
-@@ -69,16 +71,16 @@ singleton      :: a -> Seq a
- lcons          :: a -> Seq a -> Seq a
- rcons          :: a -> Seq a -> Seq a
- append         :: Seq a -> Seq a -> Seq a
--lview          :: (Monad m) => Seq a -> m (a, Seq a)
-+lview          :: (Fail.MonadFail m) => Seq a -> m (a, Seq a)
- lhead          :: Seq a -> a
--lheadM         :: (Monad m) => Seq a -> m a
-+lheadM         :: (Fail.MonadFail m) => Seq a -> m a
- ltail          :: Seq a -> Seq a
--ltailM         :: (Monad m) => Seq a -> m (Seq a)
--rview          :: (Monad m) => Seq a -> m (a, Seq a)
-+ltailM         :: (Fail.MonadFail m) => Seq a -> m (Seq a)
-+rview          :: (Fail.MonadFail m) => Seq a -> m (a, Seq a)
- rhead          :: Seq a -> a
--rheadM         :: (Monad m) => Seq a -> m a
-+rheadM         :: (Fail.MonadFail m) => Seq a -> m a
- rtail          :: Seq a -> Seq a
--rtailM         :: (Monad m) => Seq a -> m (Seq a)
-+rtailM         :: (Fail.MonadFail m) => Seq a -> m (Seq a)
- null           :: Seq a -> Bool
- size           :: Seq a -> Int
- concat         :: Seq (Seq a) -> Seq a
-@@ -109,7 +111,7 @@ reduce1'       :: (a -> a -> a) -> Seq a -> a
- copy           :: Int -> a -> Seq a
- inBounds       :: Int -> Seq a -> Bool
- lookup         :: Int -> Seq a -> a
--lookupM        :: (Monad m) => Int -> Seq a -> m a
-+lookupM        :: (Fail.MonadFail m) => Int -> Seq a -> m a
- lookupWithDefault :: a -> Int -> Seq a -> a
- update         :: Int -> a -> Seq a -> Seq a
- adjust         :: (a -> a) -> Int -> Seq a -> Seq a
-@@ -269,7 +271,7 @@ inBounds i xs = inb xs i
-           | i < j     = (i >= 0)
-           | otherwise = inb xs (i - j)
- 
--lookup i xs = runIdentity (lookupM i xs)
-+lookup i xs = runFail_ (lookupM i xs)
- 
- lookupM i xs = look xs i
-   where look E _ = fail "RandList.lookup bad subscript"
-diff --git a/src/Data/Edison/Seq/RevSeq.hs b/src/Data/Edison/Seq/RevSeq.hs
-index 3652c7b..87deea6 100644
---- a/src/Data/Edison/Seq/RevSeq.hs
-+++ b/src/Data/Edison/Seq/RevSeq.hs
-@@ -62,6 +62,7 @@ import qualified Data.Edison.Seq as S
- import qualified Data.Edison.Seq.ListSeq as L
- import Data.Edison.Seq.Defaults -- only used by concatMap
- import Control.Monad
-+import qualified Control.Monad.Fail as Fail
- import Data.Monoid
- import Data.Semigroup as SG
- import Test.QuickCheck
-@@ -75,16 +76,16 @@ singleton      :: S.Sequence s => a -> Rev s a
- lcons          :: S.Sequence s => a -> Rev s a -> Rev s a
- rcons          :: S.Sequence s => a -> Rev s a -> Rev s a
- append         :: S.Sequence s => Rev s a -> Rev s a -> Rev s a
--lview          :: (S.Sequence s, Monad m) => Rev s a -> m (a, Rev s a)
-+lview          :: (S.Sequence s, Fail.MonadFail m) => Rev s a -> m (a, Rev s a)
- lhead          :: S.Sequence s => Rev s a -> a
--lheadM         :: (S.Sequence s, Monad m) => Rev s a -> m a
-+lheadM         :: (S.Sequence s, Fail.MonadFail m) => Rev s a -> m a
- ltail          :: S.Sequence s => Rev s a -> Rev s a
--ltailM         :: (S.Sequence s, Monad m) => Rev s a -> m (Rev s a)
--rview          :: (S.Sequence s, Monad m) => Rev s a -> m (a, Rev s a)
-+ltailM         :: (S.Sequence s, Fail.MonadFail m) => Rev s a -> m (Rev s a)
-+rview          :: (S.Sequence s, Fail.MonadFail m) => Rev s a -> m (a, Rev s a)
- rhead          :: S.Sequence s => Rev s a -> a
--rheadM         :: (S.Sequence s, Monad m) => Rev s a -> m a
-+rheadM         :: (S.Sequence s, Fail.MonadFail m) => Rev s a -> m a
- rtail          :: S.Sequence s => Rev s a -> Rev s a
--rtailM         :: (S.Sequence s, Monad m) => Rev s a -> m (Rev s a)
-+rtailM         :: (S.Sequence s, Fail.MonadFail m) => Rev s a -> m (Rev s a)
- null           :: S.Sequence s => Rev s a -> Bool
- size           :: S.Sequence s => Rev s a -> Int
- concat         :: S.Sequence s => Rev s (Rev s a) -> Rev s a
-@@ -115,7 +116,7 @@ reduce1'       :: S.Sequence s => (a -> a -> a) -> Rev s a -> a
- copy           :: S.Sequence s => Int -> a -> Rev s a
- inBounds       :: S.Sequence s => Int -> Rev s a -> Bool
- lookup         :: S.Sequence s => Int -> Rev s a -> a
--lookupM        :: (S.Sequence s, Monad m) => Int -> Rev s a -> m a
-+lookupM        :: (S.Sequence s, Fail.MonadFail m) => Int -> Rev s a -> m a
- lookupWithDefault :: S.Sequence s => a -> Int -> Rev s a -> a
- update         :: S.Sequence s => Int -> a -> Rev s a -> Rev s a
- adjust         :: S.Sequence s => (a -> a) -> Int -> Rev s a -> Rev s a
-diff --git a/src/Data/Edison/Seq/SimpleQueue.hs b/src/Data/Edison/Seq/SimpleQueue.hs
-index 64592b6..754108f 100644
---- a/src/Data/Edison/Seq/SimpleQueue.hs
-+++ b/src/Data/Edison/Seq/SimpleQueue.hs
-@@ -59,6 +59,7 @@ import qualified Data.Edison.Seq.ListSeq as L
- import Data.Monoid
- import Data.Semigroup as SG
- import Control.Monad
-+import qualified Control.Monad.Fail as Fail
- import Test.QuickCheck
- 
- -- signatures for exported functions
-@@ -68,16 +69,16 @@ singleton      :: a -> Seq a
- lcons          :: a -> Seq a -> Seq a
- rcons          :: a -> Seq a -> Seq a
- append         :: Seq a -> Seq a -> Seq a
--lview          :: (Monad m) => Seq a -> m (a, Seq a)
-+lview          :: (Fail.MonadFail m) => Seq a -> m (a, Seq a)
- lhead          :: Seq a -> a
--lheadM         :: (Monad m) => Seq a -> m a
-+lheadM         :: (Fail.MonadFail m) => Seq a -> m a
- ltail          :: Seq a -> Seq a
--ltailM         :: (Monad m) => Seq a -> m (Seq a)
--rview          :: (Monad m) => Seq a -> m (a, Seq a)
-+ltailM         :: (Fail.MonadFail m) => Seq a -> m (Seq a)
-+rview          :: (Fail.MonadFail m) => Seq a -> m (a, Seq a)
- rhead          :: Seq a -> a
--rheadM         :: (Monad m) => Seq a -> m a
-+rheadM         :: (Fail.MonadFail m) => Seq a -> m a
- rtail          :: Seq a -> Seq a
--rtailM         :: (Monad m) => Seq a -> m (Seq a)
-+rtailM         :: (Fail.MonadFail m) => Seq a -> m (Seq a)
- null           :: Seq a -> Bool
- size           :: Seq a -> Int
- concat         :: Seq (Seq a) -> Seq a
-@@ -108,7 +109,7 @@ reduce1'       :: (a -> a -> a) -> Seq a -> a
- copy           :: Int -> a -> Seq a
- inBounds       :: Int -> Seq a -> Bool
- lookup         :: Int -> Seq a -> a
--lookupM        :: (Monad m) => Int -> Seq a -> m a
-+lookupM        :: (Fail.MonadFail m) => Int -> Seq a -> m a
- lookupWithDefault :: a -> Int -> Seq a -> a
- update         :: Int -> a -> Seq a -> Seq a
- adjust         :: (a -> a) -> Int -> Seq a -> Seq a
-diff --git a/src/Data/Edison/Seq/SizedSeq.hs b/src/Data/Edison/Seq/SizedSeq.hs
-index a50b800..65c0ee9 100644
---- a/src/Data/Edison/Seq/SizedSeq.hs
-+++ b/src/Data/Edison/Seq/SizedSeq.hs
-@@ -54,6 +54,7 @@ import Data.Edison.Seq.Defaults -- only used by concatMap
- import Data.Monoid
- import Data.Semigroup as SG
- import Control.Monad
-+import qualified Control.Monad.Fail as Fail
- import Test.QuickCheck
- 
- 
-@@ -65,16 +66,16 @@ singleton      :: S.Sequence s => a -> Sized s a
- lcons          :: S.Sequence s => a -> Sized s a -> Sized s a
- rcons          :: S.Sequence s => a -> Sized s a -> Sized s a
- append         :: S.Sequence s => Sized s a -> Sized s a -> Sized s a
--lview          :: (S.Sequence s, Monad m) => Sized s a -> m (a, Sized s a)
-+lview          :: (S.Sequence s, Fail.MonadFail m) => Sized s a -> m (a, Sized s a)
- lhead          :: S.Sequence s => Sized s a -> a
--lheadM         :: (S.Sequence s, Monad m) => Sized s a -> m a
-+lheadM         :: (S.Sequence s, Fail.MonadFail m) => Sized s a -> m a
- ltail          :: S.Sequence s => Sized s a -> Sized s a
--ltailM         :: (S.Sequence s, Monad m) => Sized s a -> m (Sized s a)
--rview          :: (S.Sequence s, Monad m) => Sized s a -> m (a, Sized s a)
-+ltailM         :: (S.Sequence s, Fail.MonadFail m) => Sized s a -> m (Sized s a)
-+rview          :: (S.Sequence s, Fail.MonadFail m) => Sized s a -> m (a, Sized s a)
- rhead          :: S.Sequence s => Sized s a -> a
--rheadM         :: (S.Sequence s, Monad m) => Sized s a -> m a
-+rheadM         :: (S.Sequence s, Fail.MonadFail m) => Sized s a -> m a
- rtail          :: S.Sequence s => Sized s a -> Sized s a
--rtailM         :: (S.Sequence s, Monad m) => Sized s a -> m (Sized s a)
-+rtailM         :: (S.Sequence s, Fail.MonadFail m) => Sized s a -> m (Sized s a)
- null           :: S.Sequence s => Sized s a -> Bool
- size           :: S.Sequence s => Sized s a -> Int
- concat         :: S.Sequence s => Sized s (Sized s a) -> Sized s a
-@@ -105,7 +106,7 @@ reduce1'       :: S.Sequence s => (a -> a -> a) -> Sized s a -> a
- copy           :: S.Sequence s => Int -> a -> Sized s a
- inBounds       :: S.Sequence s => Int -> Sized s a -> Bool
- lookup         :: S.Sequence s => Int -> Sized s a -> a
--lookupM        :: (S.Sequence s, Monad m) => Int -> Sized s a -> m a
-+lookupM        :: (S.Sequence s, Fail.MonadFail m) => Int -> Sized s a -> m a
- lookupWithDefault :: S.Sequence s => a -> Int -> Sized s a -> a
- update         :: S.Sequence s => Int -> a -> Sized s a -> Sized s a
- adjust         :: S.Sequence s => (a -> a) -> Int -> Sized s a -> Sized s a
-