Bounds checking, add push method

Author: paf31

README.md

@@ -123,9 +123,11 @@
 
     emptySTArray :: forall a h r. Eff (st :: ST h | r) (STArray h a)
 
-    peekSTArray :: forall a h r. STArray h a -> Number -> Eff (st :: ST h | r) a
+    peekSTArray :: forall a h r. STArray h a -> Number -> Eff (st :: ST h | r) (Maybe a)
 
-    pokeSTArray :: forall a h r. STArray h a -> Number -> a -> Eff (st :: ST h | r) Unit
+    pokeSTArray :: forall a h r. STArray h a -> Number -> a -> Eff (st :: ST h | r) Boolean
+
+    pushSTArray :: forall a h r. STArray h a -> a -> Eff (st :: ST h | r) Unit
 
     runSTArray :: forall a r. (forall h. Eff (st :: ST h | r) (STArray h a)) -> Eff r [a]
 

src/Data/Array/ST.purs

@@ -4,8 +4,12 @@ module Data.Array.ST
   , emptySTArray
   , peekSTArray
   , pokeSTArray  
+  , pushSTArray  
   ) where
 
+import Data.Maybe
+import Data.Function
+
 import Control.Monad.Eff
 import Control.Monad.ST (ST())
 
@@ -21,23 +25,52 @@ foreign import emptySTArray """
     return [];
   }""" :: forall a h r. Eff (st :: ST h | r) (STArray h a)
 
-foreign import peekSTArray """
-  function peekSTArray(arr) {
-    return function(i) {
-      return function() {
-        return arr[i];
-      };
+foreign import peekSTArrayImpl """
+  function peekSTArrayImpl(arr, i, s, f) {
+    return function() {
+      var index = ~~i;
+      if (0 <= index && index < arr.length) {
+        return s(arr[index]);
+      } else {
+        return f;
+      }
     };
-  }""" :: forall a h r. STArray h a -> Number -> Eff (st :: ST h | r) a
+  }""" :: forall a h e r. Fn4 (STArray h a) 
+                              Number 
+                              (a -> r)
+                              r
+                              (Eff (st :: ST h | e) r)
 
-foreign import pokeSTArray """
-  function pokeSTArray(arr) {
-    return function(i) {
-      return function(a) {
-        return function() {
-          arr[i] = a;
-          return {};
-        };
-      };
+peekSTArray :: forall a h r. STArray h a -> Number -> Eff (st :: ST h | r) (Maybe a)
+peekSTArray arr i = runFn4 peekSTArrayImpl arr i Just Nothing
+
+foreign import pokeSTArrayImpl """
+  function pokeSTArrayImpl(arr, i, a) {
+    return function() {
+      var index = ~~i;
+      if (0 <= index && index <= arr.length) {
+        arr[index] = a;
+        return true;
+      }
+      return false;
+    };
+  }""" :: forall a h e. Fn3 (STArray h a)
+                            Number
+                            a
+                            (Eff (st :: ST h | e) Boolean)
+  
+pokeSTArray :: forall a h r. STArray h a -> Number -> a -> Eff (st :: ST h | r) Boolean
+pokeSTArray arr i a = runFn3 pokeSTArrayImpl arr i a
+
+foreign import pushSTArrayImpl """
+  function pushSTArrayImpl(arr, a) {
+    return function() {
+      arr.push(a);
+      return {};
     };
-  }""" :: forall a h r. STArray h a -> Number -> a -> Eff (st :: ST h | r) Unit
+  }""" :: forall a h e. Fn2 (STArray h a)
+                            a
+                            (Eff (st :: ST h | e) Unit)
+                            
+pushSTArray :: forall a h r. STArray h a -> a -> Eff (st :: ST h | r) Unit
+pushSTArray arr a = runFn2 pushSTArrayImpl arr a