Merge pull request #6 from vinniegarcia/develop

compose and sequence as applications of accumulate and wrap

package.json

@@ -1,6 +1,6 @@
 {
   "name": "hoff",
-  "version": "1.2.0",
+  "version": "1.3.1",
   "description": "A collection of higher order functions you may find useful",
   "main": "dist/index.js",
   "scripts": {

src/index.es6

@@ -1,5 +1,7 @@
 'use strict';
 
+import 'babel/polyfill';
+
 export accumulate from './lib/accumulate';
 export compose from './lib/compose';
 export curry from './lib/curry';
@@ -8,4 +10,4 @@ export lift from './lib/lift';
 export not from './lib/not';
 export partial from './lib/partial';
 export partition from './lib/partition';
-export sequence from './lib/sequence';
+export sequence from './lib/sequence';

src/lib/accumulate.es6

@@ -1,5 +1,6 @@
 'use strict';
 
-const accumulate = (fn, iv) => (...args) => args.reduce(fn, iv);
+const accumulate = (reducer, iv) => (...args) => args.reduce(reducer, iv);
+export const reverse = (reducer, iv) => (...args) => args.reduceRight(reducer, iv);
 
-export default accumulate;
+export default accumulate;

src/lib/compose.es6

@@ -1,8 +1,11 @@
 // function composition
 // compose(f, g)(x) = g(f(x))
 'use strict';
+import wrap from './wrap';
 import unwrap from './unwrap';
+import identity from './identity';
+import {reverse} from './accumulate';
 
-const compose = (...funcs) => (...args) => unwrap(funcs.reduceRight((current, next) => [next(...current)], args));
+const compose = (...funcs) => (...args) => unwrap(reverse(wrap, args)(...funcs));
 
-export default compose;
+export default compose;

src/lib/lift.es6

@@ -4,4 +4,4 @@ import identity from './identity';
 
 const lift = (fn, lifter = identity) => (...args) => fn(...args.map(lifter));
 
-export default lift;
+export default lift;

src/lib/sequence.es6

@@ -1,8 +1,11 @@
 // function sequencing
 // compose(f, g)(x) = f(g(x))
 'use strict';
+import wrap from './wrap';
 import unwrap from './unwrap';
+import identity from './identity';
+import accumulate from './accumulate';
 
-const sequence = (...funcs) => (...args) => unwrap(funcs.reduce((current, next) => [next(...current)], args));
+const sequence = (...funcs) => (...args) => unwrap(accumulate(wrap, args)(...funcs));
 
-export default sequence;
+export default sequence;

src/lib/unwrap.es6

@@ -1,6 +1,6 @@
 'use strict';
 // return first element of an array
 // without any array packing
-const unwrap = ([first,]) => first;
+const unwrap = ([first,...rest]) => first;
 
 export default unwrap;

src/lib/wrap.es6

@@ -1,5 +1,5 @@
 'use strict';
 
-const wrap = (fn, n) => fn(n);
+const wrap = (n, fn) => [fn(...n)];
 
 export default wrap;

src/test/compose.es6

@@ -1,3 +1,5 @@
+'use strict';
+
 import test from 'tape';
 import compose from '../lib/compose';
 import {add, dub, sq} from './util/simpleFunctions';

src/test/wrap.es6

@@ -2,6 +2,7 @@
 
 import test from 'tape';
 import wrap from '../lib/wrap';
+import unwrap from '../lib/unwrap';
 import partial from '../lib/partial';
 import {add} from './util/simpleFunctions';
 
@@ -11,11 +12,11 @@ test('Wrap test', (t) => {
   const a = '3',
     b = '4',
     addStrings = add(a,b),
-    numify = partial(wrap, Number),
-    addNums = add(numify(a), numify(b));
+    numify = (n) => wrap(n, Number),
+    addNums = add(unwrap(numify(a)), unwrap(numify(b)));
 
   t.is(addStrings, '34', 'strings were added');
-  t.is(numify(a), 3, 'wrap converted to Number');
+  t.same(numify(a), [3], 'wrap converted to Array<Number>');
   t.is(addNums, 7, 'conversion was successful');
 
 });