From e9d61b79faf40200d8f9806d83a05ece272cd7d3 Mon Sep 17 00:00:00 2001
From: Łukasz Hanuszczak <lukasz.hanuszczak@gmail.com>
Date: Fri, 10 Jul 2015 11:42:18 +0200
Subject: Move SYB utilities to standalone module.

---
 haddock-api/src/Haddock/Syb.hs | 26 ++++++++++++++++++++++++++
 1 file changed, 26 insertions(+)
 create mode 100644 haddock-api/src/Haddock/Syb.hs

(limited to 'haddock-api/src/Haddock/Syb.hs')

diff --git a/haddock-api/src/Haddock/Syb.hs b/haddock-api/src/Haddock/Syb.hs
new file mode 100644
index 00000000..dd7ffc1b
--- /dev/null
+++ b/haddock-api/src/Haddock/Syb.hs
@@ -0,0 +1,26 @@
+{-# LANGUAGE Rank2Types #-}
+
+
+module Haddock.Syb
+    ( everything
+    , combine
+    ) where
+
+
+import Data.Data
+import Control.Applicative
+
+
+-- | Perform a query on each level of a tree.
+--
+-- This is stolen directly from SYB package and copied here to not introduce
+-- additional dependencies.
+everything :: (r -> r -> r) -> (forall a. Data a => a -> r)
+           -> (forall a. Data a => a -> r)
+everything k f x = foldl k (f x) (gmapQ (everything k f) x)
+
+-- | Combine two queries into one using alternative combinator.
+combine :: Alternative f => (forall a. Data a => a -> f r)
+                         -> (forall a. Data a => a -> f r)
+                         -> (forall a. Data a => a -> f r)
+combine f g x = f x <|> g x
-- 
cgit v1.2.3


From f7d377ee238d3b44240a4537986a7561e822f79f Mon Sep 17 00:00:00 2001
From: Łukasz Hanuszczak <lukasz.hanuszczak@gmail.com>
Date: Fri, 10 Jul 2015 11:49:02 +0200
Subject: Implement `everywhere` transformation in SYB module.

---
 haddock-api/src/Haddock/Syb.hs | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

(limited to 'haddock-api/src/Haddock/Syb.hs')

diff --git a/haddock-api/src/Haddock/Syb.hs b/haddock-api/src/Haddock/Syb.hs
index dd7ffc1b..3cec724e 100644
--- a/haddock-api/src/Haddock/Syb.hs
+++ b/haddock-api/src/Haddock/Syb.hs
@@ -2,7 +2,7 @@
 
 
 module Haddock.Syb
-    ( everything
+    ( everything, everywhere
     , combine
     ) where
 
@@ -19,6 +19,12 @@ everything :: (r -> r -> r) -> (forall a. Data a => a -> r)
            -> (forall a. Data a => a -> r)
 everything k f x = foldl k (f x) (gmapQ (everything k f) x)
 
+-- | Apply transformation on each level of a tree.
+--
+-- Just like 'everything', this is stolen from SYB package.
+everywhere :: (forall a. Data a => a -> a) -> (forall a. Data a => a -> a)
+everywhere f = f . gmapT (everywhere f)
+
 -- | Combine two queries into one using alternative combinator.
 combine :: Alternative f => (forall a. Data a => a -> f r)
                          -> (forall a. Data a => a -> f r)
-- 
cgit v1.2.3


From dc25b7099a0d54c03bdf51dfb9a4e286942d9c31 Mon Sep 17 00:00:00 2001
From: Łukasz Hanuszczak <lukasz.hanuszczak@gmail.com>
Date: Fri, 10 Jul 2015 12:24:12 +0200
Subject: Implement generic transformation constructor.

---
 haddock-api/src/Haddock/Syb.hs | 9 +++++++++
 1 file changed, 9 insertions(+)

(limited to 'haddock-api/src/Haddock/Syb.hs')

diff --git a/haddock-api/src/Haddock/Syb.hs b/haddock-api/src/Haddock/Syb.hs
index 3cec724e..2016b74c 100644
--- a/haddock-api/src/Haddock/Syb.hs
+++ b/haddock-api/src/Haddock/Syb.hs
@@ -3,6 +3,7 @@
 
 module Haddock.Syb
     ( everything, everywhere
+    , mkT
     , combine
     ) where
 
@@ -25,6 +26,14 @@ everything k f x = foldl k (f x) (gmapQ (everything k f) x)
 everywhere :: (forall a. Data a => a -> a) -> (forall a. Data a => a -> a)
 everywhere f = f . gmapT (everywhere f)
 
+-- | Create generic transformation.
+--
+-- Another function stolen from SYB package.
+mkT :: (Typeable a, Typeable b) => (b -> b) -> (a -> a)
+mkT f = case cast f of
+    Just f' -> f'
+    Nothing -> id
+
 -- | Combine two queries into one using alternative combinator.
 combine :: Alternative f => (forall a. Data a => a -> f r)
                          -> (forall a. Data a => a -> f r)
-- 
cgit v1.2.3


From d5700e1427f7171db0e0e9393aedb734b554459f Mon Sep 17 00:00:00 2001
From: Łukasz Hanuszczak <lukasz.hanuszczak@gmail.com>
Date: Sun, 19 Jul 2015 18:16:11 +0200
Subject: Add SYB-like utility function for performing stateful queries.

---
 haddock-api/src/Haddock/Syb.hs | 16 +++++++++++++++-
 1 file changed, 15 insertions(+), 1 deletion(-)

(limited to 'haddock-api/src/Haddock/Syb.hs')

diff --git a/haddock-api/src/Haddock/Syb.hs b/haddock-api/src/Haddock/Syb.hs
index 2016b74c..4847e486 100644
--- a/haddock-api/src/Haddock/Syb.hs
+++ b/haddock-api/src/Haddock/Syb.hs
@@ -2,7 +2,7 @@
 
 
 module Haddock.Syb
-    ( everything, everywhere
+    ( everything, everythingWithState, everywhere
     , mkT
     , combine
     ) where
@@ -20,6 +20,20 @@ everything :: (r -> r -> r) -> (forall a. Data a => a -> r)
            -> (forall a. Data a => a -> r)
 everything k f x = foldl k (f x) (gmapQ (everything k f) x)
 
+
+-- | Perform a query with state on each level of a tree.
+--
+-- This is the same as 'everything' but allows for stateful computations. In
+-- SYB it is called @everythingWithContext@ but I find this name somewhat
+-- nicer.
+everythingWithState :: s -> (r -> r -> r)
+                    -> (forall a. Data a => a -> s -> (r, s))
+                    -> (forall a. Data a => a -> r)
+everythingWithState s k f x =
+    let (r, s') = f x s
+    in foldl k r (gmapQ (everythingWithState s' k f) x)
+
+
 -- | Apply transformation on each level of a tree.
 --
 -- Just like 'everything', this is stolen from SYB package.
-- 
cgit v1.2.3