From f984324bba7f12731a1dbb12fe119b9b4a85d149 Mon Sep 17 00:00:00 2001
From: Stefano Vozza <svozza@gmail.com>
Date: Sun, 8 May 2016 23:04:35 +0100
Subject: [PATCH] add S.keys and S.values

---
 index.js       | 42 ++++++++++++++++++++++++++++++++++++
 test/keys.js   | 58 ++++++++++++++++++++++++++++++++++++++++++++++++++
 test/values.js | 58 ++++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 158 insertions(+)
 create mode 100644 test/keys.js
 create mode 100644 test/values.js

diff --git a/index.js b/index.js
index 7ca1f215..680b58cf 100644
--- a/index.js
+++ b/index.js
@@ -166,6 +166,8 @@
 
   var sentinel = {};
 
+  var hasOwnProperty = Object.prototype.hasOwnProperty;
+
   //  _type :: a -> String
   var _type = function(x) {
     return x != null && R.type(x['@@type']) === 'String' ? x['@@type']
@@ -362,6 +364,14 @@
         }
       });
 
+  //  keys :: StrMap a -> Array String
+  var keys = function(strMap) {
+    if(typeof Object.keys === 'function') return Object.keys(strMap);
+    var ks = [];
+    for (var k in strMap) if (hasOwnProperty(k, strMap)) ks.push(k);
+    return ks;
+  };
+
   //. ### Classify
 
   //# type :: a -> String
@@ -2683,6 +2693,38 @@
         return filter(is(type), Just(x));
       });
 
+  //# keys :: StrMap a -> Array String
+  //.
+  //. Returns a list containing the keys of the supplied StrMap.
+  //.
+  //. ```javascript
+  //. > S.keys({a: 1, b: 2, c:3})
+  //. ['a', 'b', 'c']
+  //. ```
+  S.keys =
+  def('keys',
+      {},
+      [$.StrMap(a), $.Array($.String)],
+      keys);
+
+  //# values :: StrMap a -> Array a
+  //.
+  //. Returns a list containing the values of the supplied StrMap.
+  //.
+  //. ```javascript
+  //. > S.values({a: 1, b: 2, c:3})
+  //. [1, 2, 3]
+  //. ```
+  S.values =
+  def('values',
+      {},
+      [$.StrMap(a), $.Array(a)],
+      function(obj) {
+        return keys(obj).map(function(key) {
+          return obj[key];
+        });
+      });
+
   //. ### Number
 
   //# negate :: ValidNumber -> ValidNumber
diff --git a/test/keys.js b/test/keys.js
new file mode 100644
index 00000000..3eb58a09
--- /dev/null
+++ b/test/keys.js
@@ -0,0 +1,58 @@
+'use strict';
+
+var throws = require('assert').throws;
+
+var eq = require('./utils').eq;
+var errorEq = require('./utils').errorEq;
+var S = require('..');
+
+
+describe('keys', function() {
+
+  it('is a unary function', function() {
+    eq(typeof S.keys, 'function');
+    eq(S.keys.length, 1);
+  });
+
+  it('type checks its arguments', function() {
+    throws(function() { S.keys('xxx'); },
+           errorEq(TypeError,
+                   'Invalid value\n' +
+                   '\n' +
+                   'keys :: StrMap a -> Array String\n' +
+                   '        ^^^^^^^^\n' +
+                   '           1\n' +
+                   '\n' +
+                   '1)  "xxx" :: String\n' +
+                   '\n' +
+                   'The value at position 1 is not a member of ‘StrMap a’.\n'));
+
+    throws(function() { S.keys({a: '1', b: 2, c: '3'}); },
+           errorEq(TypeError,
+                   'Type-variable constraint violation\n' +
+                   '\n' +
+                   'keys :: StrMap a -> Array String\n' +
+                   '               ^\n' +
+                   '               1\n' +
+                   '\n' +
+                   '1)  "1" :: String\n' +
+                   '    2 :: Number, FiniteNumber, NonZeroFiniteNumber, Integer, ValidNumber\n' +
+                   '    "3" :: String\n' +
+                   '\n' +
+                   'Since there is no type of which all the above values are members, the type-variable constraint has been violated.\n'));
+  });
+
+  it("returns an array of the given object's own keys", function() {
+    eq(S.keys({a: 1, b: 2, c: 3}).sort(), ['a', 'b', 'c']);
+  });
+
+  it('does not include prototype properties', function() {
+    var proto = {a: 1, b: 2};
+    var obj = Object.create(proto);
+    obj.c = 3;
+    obj.d = 4;
+
+    eq(S.keys(obj).sort(), ['c', 'd']);
+  });
+
+});
diff --git a/test/values.js b/test/values.js
new file mode 100644
index 00000000..96aafbca
--- /dev/null
+++ b/test/values.js
@@ -0,0 +1,58 @@
+'use strict';
+
+var throws = require('assert').throws;
+
+var eq = require('./utils').eq;
+var errorEq = require('./utils').errorEq;
+var S = require('..');
+
+
+describe('values', function() {
+
+  it('is a unary function', function() {
+    eq(typeof S.values, 'function');
+    eq(S.values.length, 1);
+  });
+
+  it('type checks its arguments', function() {
+    throws(function() { S.values('xxx'); },
+           errorEq(TypeError,
+                   'Invalid value\n' +
+                   '\n' +
+                   'values :: StrMap a -> Array a\n' +
+                   '          ^^^^^^^^\n' +
+                   '             1\n' +
+                   '\n' +
+                   '1)  "xxx" :: String\n' +
+                   '\n' +
+                   'The value at position 1 is not a member of ‘StrMap a’.\n'));
+
+    throws(function() { S.values({a: '1', b: 2, c: '3'}); },
+           errorEq(TypeError,
+                   'Type-variable constraint violation\n' +
+                   '\n' +
+                   'values :: StrMap a -> Array a\n' +
+                   '                 ^\n' +
+                   '                 1\n' +
+                   '\n' +
+                   '1)  "1" :: String\n' +
+                   '    2 :: Number, FiniteNumber, NonZeroFiniteNumber, Integer, ValidNumber\n' +
+                   '    "3" :: String\n' +
+                   '\n' +
+                   'Since there is no type of which all the above values are members, the type-variable constraint has been violated.\n'));
+  });
+
+  it("returns an array of the given object's own values", function() {
+    eq(S.values({a: 1, b: 2, c: 3}).sort(), [1, 2, 3]);
+  });
+
+  it('does not include prototype values', function() {
+    var proto = {a: 1, b: 2};
+    var obj = Object.create(proto);
+    obj.c = 3;
+    obj.d = 4;
+
+    eq(S.values(obj).sort(), [3, 4]);
+  });
+
+});