From 425c2867708bbb43dec1f8d9094c5f8fbaa78038 Mon Sep 17 00:00:00 2001
From: cfhammill <cfhammill@gmail.com>
Date: Tue, 27 Mar 2018 13:33:53 -0400
Subject: [PATCH 1/3] Add lsdepth, findtree, cmin, and cmax

As discussed in #298
---
 src/Turtle/Prelude.hs | 57 ++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 56 insertions(+), 1 deletion(-)

diff --git a/src/Turtle/Prelude.hs b/src/Turtle/Prelude.hs
index 50f3f9c..f1b6a05 100644
--- a/src/Turtle/Prelude.hs
+++ b/src/Turtle/Prelude.hs
@@ -170,6 +170,7 @@ module Turtle.Prelude (
     , ls
     , lsif
     , lstree
+    , lsdepth
     , cat
     , grep
     , grepText
@@ -183,6 +184,7 @@ module Turtle.Prelude (
     , inplaceSuffix
     , inplaceEntire
     , find
+    , findtree
     , yes
     , nl
     , paste
@@ -269,6 +271,8 @@ module Turtle.Prelude (
     , PosixCompat.isDirectory
     , PosixCompat.isSymbolicLink
     , PosixCompat.isSocket
+    , cmin
+    , cmax
 
     -- * Headers
     , WithHeader(..)
@@ -305,7 +309,7 @@ import Data.Ord (comparing)
 import qualified Data.Set as Set
 import Data.Text (Text, pack, unpack)
 import Data.Time (NominalDiffTime, UTCTime, getCurrentTime)
-import Data.Time.Clock.POSIX (POSIXTime)
+import Data.Time.Clock.POSIX (POSIXTime, posixSecondsToUTCTime)
 import Data.Traversable
 import qualified Data.Text    as Text
 import qualified Data.Text.IO as Text
@@ -1005,6 +1009,29 @@ lstree path = do
         then return child <|> lstree child
         else return child
 
+
+{- | Stream the recursive descendents of a given directory
+     between a given minimum and maximum depth
+-}
+lsdepth :: Int -> Int -> FilePath -> Shell FilePath
+lsdepth mn mx path =
+  lsdepthHelper 1 mn mx path
+  where
+    lsdepthHelper :: Int -> Int -> Int -> FilePath -> Shell FilePath
+    lsdepthHelper depth l u p = 
+      if depth > u
+      then empty
+      else do
+        child <- ls p
+        isDir <- testdir child
+        if isDir
+          then if depth >= l
+               then return child <|> lsdepthHelper (depth + 1) l u child
+               else lsdepthHelper (depth + 1) l u child
+          else if depth >= l
+               then return child
+               else empty
+
 {-| Stream all recursive descendents of the given directory
 
     This skips any directories that fail the supplied predicate
@@ -1635,6 +1662,34 @@ find pattern dir = do
       file_stat <- lstat file
       return (not (PosixCompat.isSymbolicLink file_stat))
 
+-- | Filter a shell of FilePaths according to a given pattern
+findtree :: Pattern a -> Shell FilePath -> Shell FilePath
+findtree pat files = do
+  path <- files
+  Right txt <- return (Filesystem.toText path)
+  _:_ <- return (match pat txt)
+  return path
+
+{- | Check if a file was last modified after a given
+     timestamp
+-}     
+cmin :: MonadIO io => UTCTime -> FilePath -> io Bool
+cmin t file =
+  (> t) .
+  posixSecondsToUTCTime .
+  modificationTime <$>
+  lstat file
+
+{- | Check if a file was last modified after a given
+     timestamp
+-}     
+cmax :: MonadIO io => UTCTime -> FilePath -> io Bool
+cmax t file =
+  (< t) .
+  posixSecondsToUTCTime .
+  modificationTime <$>
+  lstat file
+  
 -- | A Stream of @\"y\"@s
 yes :: Shell Line
 yes = fmap (\_ -> "y") endless

From a165f144e248450aa46f2d0e6da8a604543dc02b Mon Sep 17 00:00:00 2001
From: cfhammill <cfhammill@gmail.com>
Date: Wed, 28 Mar 2018 20:49:51 -0400
Subject: [PATCH 2/3] Adopt Gabe's suggestion to be more point-full

---
 src/Turtle/Prelude.hs | 16 +++++++---------
 1 file changed, 7 insertions(+), 9 deletions(-)

diff --git a/src/Turtle/Prelude.hs b/src/Turtle/Prelude.hs
index f1b6a05..ecc55ad 100644
--- a/src/Turtle/Prelude.hs
+++ b/src/Turtle/Prelude.hs
@@ -1675,20 +1675,18 @@ findtree pat files = do
 -}     
 cmin :: MonadIO io => UTCTime -> FilePath -> io Bool
 cmin t file =
-  (> t) .
-  posixSecondsToUTCTime .
-  modificationTime <$>
-  lstat file
+  adapt <$> lstat file
+  where
+    adapt x = posixSecondsToUTCTime (modificationTime x) > t
 
-{- | Check if a file was last modified after a given
+{- | Check if a file was last modified before a given
      timestamp
 -}     
 cmax :: MonadIO io => UTCTime -> FilePath -> io Bool
 cmax t file =
-  (< t) .
-  posixSecondsToUTCTime .
-  modificationTime <$>
-  lstat file
+  adapt <$> lstat file
+  where
+    adapt x = posixSecondsToUTCTime (modificationTime x) < t
   
 -- | A Stream of @\"y\"@s
 yes :: Shell Line

From bf983a7feff773c6f1324c7c6501f379db0c38cb Mon Sep 17 00:00:00 2001
From: cfhammill <cfhammill@gmail.com>
Date: Thu, 12 Apr 2018 20:17:50 -0400
Subject: [PATCH 3/3] Convert cmin and cmax to do notation

---
 src/Turtle/Prelude.hs | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/src/Turtle/Prelude.hs b/src/Turtle/Prelude.hs
index ecc55ad..ccf8a40 100644
--- a/src/Turtle/Prelude.hs
+++ b/src/Turtle/Prelude.hs
@@ -1674,8 +1674,9 @@ findtree pat files = do
      timestamp
 -}     
 cmin :: MonadIO io => UTCTime -> FilePath -> io Bool
-cmin t file =
-  adapt <$> lstat file
+cmin t file = do
+  status <- lstat file
+  return (adapt status)
   where
     adapt x = posixSecondsToUTCTime (modificationTime x) > t
 
@@ -1683,8 +1684,9 @@ cmin t file =
      timestamp
 -}     
 cmax :: MonadIO io => UTCTime -> FilePath -> io Bool
-cmax t file =
-  adapt <$> lstat file
+cmax t file = do
+  status <- lstat file
+  return (adapt status)
   where
     adapt x = posixSecondsToUTCTime (modificationTime x) < t