- WIP: Caching.

3 files changed, 30 insertions, 11 deletions

diff --git a/stdlib/source/lux/data/coll/dict.lux b/stdlib/source/lux/data/coll/dict.lux
index e00cbb17f..1091100b6 100644
--- a/stdlib/source/lux/data/coll/dict.lux
+++ b/stdlib/source/lux/data/coll/dict.lux
@@ -2,7 +2,7 @@
   lux
   (lux (control hash
                 [eq #+ Eq])
-       (data maybe
+       (data [maybe]
              (coll [list "list/" Fold<List> Functor<List> Monoid<List>]
                    [array "array/" Functor<Array> Fold<Array>])
              [bit]
@@ -212,7 +212,7 @@
 ## Produces the index of a KV-pair within a #Collisions node.
 (def: (collision-index Hash<k> key colls)
   (All [k v] (-> (Hash k) k (Collisions k v) (Maybe Index)))
-  (:: Monad<Maybe> map product.left
+  (:: maybe.Monad<Maybe> map product.left
       (array.find+ (function [idx [key' val']]
                      (:: Hash<k> = key key'))
                    colls)))
@@ -493,7 +493,7 @@
 
     ## For #Collisions nodes, do a linear scan of all the known KV-pairs.
     (#Collisions _hash _colls)
-    (:: Monad<Maybe> map product.right
+    (:: maybe.Monad<Maybe> map product.right
         (array.find (|>> product.left (:: Hash<k> = key))
                     _colls))
     ))
@@ -588,6 +588,14 @@
     (#.Some val)
     (put key (f val) dict)))
 
+(def: #export (update~ key default f dict)
+  {#.doc "Transforms the value located at key (if available), using the given function."}
+  (All [k v] (-> k v (-> v v) (Dict k v) (Dict k v)))
+  (put key
+       (f (maybe.default default
+                         (get key dict)))
+       dict))
+
 (def: #export size
   (All [k v] (-> (Dict k v) Nat))
   (|>> product.right size'))
diff --git a/stdlib/source/lux/io.lux b/stdlib/source/lux/io.lux
index 8eaeaae63..5e1f2e59e 100644
--- a/stdlib/source/lux/io.lux
+++ b/stdlib/source/lux/io.lux
@@ -2,7 +2,8 @@
   lux
   (lux (control [functor #+ Functor]
                 [applicative #+ Applicative]
-                [monad #+ do Monad])
+                [monad #+ do Monad]
+                ["ex" exception #+ Exception])
        (data ["e" error #+ Error]
              (coll [list]))))
 
@@ -79,3 +80,7 @@
 (def: #export (fail error)
   (All [a] (-> Text (Process a)))
   (io (#e.Error error)))
+
+(def: #export (throw exception message)
+  (All [a] (-> Exception Text (Process a)))
+  (io (#e.Error (exception message))))
diff --git a/stdlib/source/lux/world/file.lux b/stdlib/source/lux/world/file.lux
index 1c295da08..b173fa5ba 100644
--- a/stdlib/source/lux/world/file.lux
+++ b/stdlib/source/lux/world/file.lux
@@ -10,17 +10,18 @@
        [io #+ Process]
        [host]))
 
-(exception: Could-Not-Read-All-Data)
+(exception: #export Could-Not-Read-All-Data)
+(exception: #export Not-A-Directory)
 
 (type: #export File Text)
 
 (host.import #long java/io/File
   (new [String])
   (exists [] #io #try boolean)
-  (mkdir [] #io #try boolean)
+  (mkdirs [] #io #try boolean)
   (delete [] #io #try boolean)
   (length [] #io #try long)
-  (listFiles [] #io #try (Array java/io/File))
+  (listFiles [] #io #try #? (Array java/io/File))
   (getAbsolutePath [] #io #try String)
   (renameTo [java/io/File] #io #try boolean)
   (isFile [] #io #try boolean)
@@ -83,9 +84,14 @@
 (def: #export (files dir)
   (-> File (Process (List File)))
   (do (E.ErrorT io.Monad<IO>)
-    [files (java/io/File::listFiles [] (java/io/File::new dir))]
-    (monad.map @ (java/io/File::getAbsolutePath [])
-               (array.to-list files))))
+    [?files (java/io/File::listFiles [] (java/io/File::new dir))]
+    (case ?files
+      (#.Some files)
+      (monad.map @ (java/io/File::getAbsolutePath [])
+                 (array.to-list files))
+
+      #.None
+      (io.throw Not-A-Directory dir))))
 
 (do-template [<name> <method>]
   [(def: #export (<name> file)
@@ -93,7 +99,7 @@
      (<method> [] (java/io/File::new file)))]
 
   [exists?      java/io/File::exists]
-  [make-dir     java/io/File::mkdir]
+  [make-dir     java/io/File::mkdirs]
   [delete       java/io/File::delete]
   [file?        java/io/File::isFile]
   [directory?   java/io/File::isDirectory]