Merge pull request #534 from sanctuary-js/davidchambers/type-classes

[email protected]

bower.json

@@ -23,7 +23,7 @@
   ],
   "dependencies": {
     "sanctuary-def": "0.16.0",
-    "sanctuary-type-classes": "8.1.1",
+    "sanctuary-type-classes": "8.2.1",
     "sanctuary-type-identifiers": "2.0.1"
   },
   "ignore": [

index.js

@@ -244,6 +244,15 @@
     };
   }
 
+  //  C :: (a -> b -> c) -> b -> a -> c
+  function C(f) {
+    return function(y) {
+      return function(x) {
+        return f (x) (y);
+      };
+    };
+  }
+
   //  Fn :: Type -> Type -> Type
   function Fn(x) {
     return function(y) {
@@ -936,6 +945,40 @@
     impl: map
   };
 
+  //# flip :: Functor f => f (a -> b) -> a -> f b
+  //.
+  //. Curried version of [`Z.flip`][]. Maps over the given functions, applying
+  //. each to the given value.
+  //.
+  //. Replacing `Functor f => f` with `Function x` produces the C combinator
+  //. from combinatory logic:
+  //.
+  //.     Functor f => f (a -> b) -> a -> f b
+  //.     Function x (a -> b) -> a -> Function x b
+  //.     Function x (a -> c) -> a -> Function x c
+  //.     Function x (b -> c) -> b -> Function x c
+  //.     Function a (b -> c) -> b -> Function a c
+  //.     (a -> b -> c) -> b -> a -> c
+  //.
+  //. ```javascript
+  //. > S.flip (S.concat) ('!') ('foo')
+  //. 'foo!'
+  //.
+  //. > S.flip ([Math.floor, Math.ceil]) (1.5)
+  //. [1, 2]
+  //.
+  //. > S.flip ({floor: Math.floor, ceil: Math.ceil}) (1.5)
+  //. {floor: 1, ceil: 2}
+  //.
+  //. > S.flip (Cons (Math.floor) (Cons (Math.ceil) (Nil))) (1.5)
+  //. Cons (1) (Cons (2) (Nil))
+  //. ```
+  _.flip = {
+    consts: {f: [Z.Functor]},
+    types: [f (Fn (a) (b)), a, f (b)],
+    impl: curry2 (Z.flip)
+  };
+
   //# bimap :: Bifunctor f => (a -> b) -> (c -> d) -> f a c -> f b d
   //.
   //. Curried version of [`Z.bimap`][].
@@ -1596,30 +1639,6 @@
     impl: curry5
   };
 
-  //# flip :: (a -> b -> c) -> b -> a -> c
-  //.
-  //. Takes a curried binary function and two values, and returns the
-  //. result of applying the function to the values in reverse order.
-  //.
-  //. This is the C combinator from combinatory logic.
-  //.
-  //. ```javascript
-  //. > S.flip (S.concat) ('foo') ('bar')
-  //. 'barfoo'
-  //. ```
-  function flip(f) {
-    return function(x) {
-      return function(y) {
-        return f (y) (x);
-      };
-    };
-  }
-  _.flip = {
-    consts: {},
-    types: [Fn (a) (Fn (b) (c)), b, a, c],
-    impl: flip
-  };
-
   //. ### Composition
 
   //# compose :: Semigroupoid s => s b c -> s a b -> s a c
@@ -2216,13 +2235,10 @@
   //. > S.fromMaybe (0) (S.Nothing)
   //. 0
   //. ```
-  function fromMaybe(x) {
-    return maybe (x) (I);
-  }
   _.fromMaybe = {
     consts: {},
     types: [a, $Maybe (a), a],
-    impl: fromMaybe
+    impl: C (maybe) (I)
   };
 
   //# fromMaybe_ :: (() -> a) -> Maybe a -> a
@@ -2242,7 +2258,7 @@
   _.fromMaybe_ = {
     consts: {},
     types: [$.Thunk (a), $Maybe (a), a],
-    impl: flip (maybe_) (I)
+    impl: C (maybe_) (I)
   };
 
   //# maybeToNullable :: Maybe a -> Nullable a
@@ -3323,7 +3339,7 @@
   //. -1
   //. ```
   function when(pred) {
-    return flip (ifElse (pred)) (I);
+    return C (ifElse (pred)) (I);
   }
   _.when = {
     consts: {},
@@ -3834,6 +3850,21 @@
     impl: find
   };
 
+  //# foldMap :: (Monoid m, Foldable f) => TypeRep m -> (a -> m) -> f a -> m
+  //.
+  //. Curried version of [`Z.foldMap`][]. Deconstructs a foldable by mapping
+  //. every element to a monoid and concatenating the results.
+  //.
+  //. ```javascript
+  //. > S.foldMap (String) (f => f.name) ([Math.sin, Math.cos, Math.tan])
+  //. 'sincostan'
+  //. ```
+  _.foldMap = {
+    consts: {b: [Z.Monoid], f: [Z.Foldable]},
+    types: [TypeRep (b), Fn (a) (b), f (a), b],
+    impl: curry3 (Z.foldMap)
+  };
+
   //# unfoldr :: (b -> Maybe (Array2 a b)) -> b -> Array a
   //.
   //. Takes a function and a seed value, and returns an array generated by
@@ -5227,6 +5258,8 @@
 //. [`Z.extend`]:       v:sanctuary-js/sanctuary-type-classes#extend
 //. [`Z.extract`]:      v:sanctuary-js/sanctuary-type-classes#extract
 //. [`Z.filter`]:       v:sanctuary-js/sanctuary-type-classes#filter
+//. [`Z.flip`]:         v:sanctuary-js/sanctuary-type-classes#flip
+//. [`Z.foldMap`]:      v:sanctuary-js/sanctuary-type-classes#foldMap
 //. [`Z.gt`]:           v:sanctuary-js/sanctuary-type-classes#gt
 //. [`Z.gte`]:          v:sanctuary-js/sanctuary-type-classes#gte
 //. [`Z.id`]:           v:sanctuary-js/sanctuary-type-classes#id

package.json

@@ -15,7 +15,7 @@
   },
   "dependencies": {
     "sanctuary-def": "0.16.0",
-    "sanctuary-type-classes": "8.1.1",
+    "sanctuary-type-classes": "8.2.1",
     "sanctuary-type-identifiers": "2.0.1"
   },
   "devDependencies": {

test/flip.js

@@ -1,18 +1,26 @@
 'use strict';
 
-var S = require ('..');
+var S = require ('./internal/sanctuary');
 
+var List = require ('./internal/List');
 var eq = require ('./internal/eq');
 var map = require ('./internal/map');
 
 
+var Cons = List.Cons;
+var Nil = List.Nil;
+
+
 test ('flip', function() {
 
   eq (typeof S.flip) ('function');
   eq (S.flip.length) (1);
-  eq (String (S.flip)) ('flip :: (a -> b -> c) -> b -> a -> c');
+  eq (String (S.flip)) ('flip :: Functor f => f (a -> b) -> a -> f b');
 
   eq (S.flip (S.concat) ('foo') ('bar')) ('barfoo');
   eq (map (S.flip (S.concat) ('!')) (['BAM', 'POW', 'KA-POW'])) (['BAM!', 'POW!', 'KA-POW!']);
+  eq (S.flip ([Math.floor, Math.ceil]) (1.5)) ([1, 2]);
+  eq (S.flip ({floor: Math.floor, ceil: Math.ceil}) (1.5)) ({floor: 1, ceil: 2});
+  eq (S.flip (Cons (Math.floor) (Cons (Math.ceil) (Nil))) (1.5)) (Cons (1) (Cons (2) (Nil)));
 
 });

test/foldMap.js

@@ -0,0 +1,20 @@
+'use strict';
+
+var S = require ('..');
+
+var eq = require ('./internal/eq');
+
+
+test ('foldMap', function() {
+
+  eq (typeof S.foldMap) ('function');
+  eq (S.foldMap.length) (1);
+  eq (String (S.foldMap)) ('foldMap :: (Monoid b, Foldable f) => TypeRep b -> (a -> b) -> f a -> b');
+
+  function repeat(n) { return (new Array (n + 1)).join (String (n)); }
+  eq (S.foldMap (String) (repeat) ([])) ('');
+  eq (S.foldMap (String) (repeat) ([1])) ('1');
+  eq (S.foldMap (String) (repeat) ([1, 2])) ('122');
+  eq (S.foldMap (String) (repeat) ([1, 2, 3])) ('122333');
+
+});