add S.keys, S.values and S.pairs

sanctuary-js · May 18, 2016 · 4bc304d · 4bc304d
1 parent 4aa1b02
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diff --git a/index.js b/index.js
@@ -27,6 +27,8 @@
 //.
 //.     R.map(S.toUpper, S.head(words))
 //.
+//. Sanctuary is designed to work in Node.js and in ES5-compatible browsers.
+//.
 //. ## Types
 //.
 //. Sanctuary uses Haskell-like type signatures to describe the types of
@@ -2746,6 +2748,54 @@
         return filter(is(type), Just(x));
       });
 
+  //# keys :: StrMap a -> Array String
+  //.
+  //. Returns the keys of the given string map, in arbitrary order.
+  //.
+  //. ```javascript
+  //. > S.keys({a: 1, b: 2, c: 3})
+  //. ['a', 'b', 'c']
+  //. ```
+  S.keys =
+  def('keys',
+      {},
+      [$.StrMap(a), $.Array($.String)],
+      Object.keys);
+
+  //# values :: StrMap a -> Array a
+  //.
+  //. Returns the values of the given string map, in arbitrary order.
+  //.
+  //. ```javascript
+  //. > S.values({a: 1, b: 2, c: 3})
+  //. [1, 2, 3]
+  //. ```
+  S.values =
+  def('values',
+      {},
+      [$.StrMap(a), $.Array(a)],
+      function(strMap) {
+        var xs = Object.keys(strMap);
+        for (var idx = 0; idx < xs.length; idx += 1) xs[idx] = strMap[xs[idx]];
+        return xs;
+      });
+
+  //# toPairs :: StrMap a -> Array (Pair String a)
+  //.
+  //. Returns the key–value pairs of the given string map, in arbitrary order.
+  //.
+  //. ```javascript
+  //. > S.pairs({a: 1, b: 2, c: 3})
+  //. [['a', 1], ['b', 2], ['c', 3]]
+  //. ```
+  S.pairs =
+  def('pairs',
+      {},
+      [$.StrMap(a), $.Array($.Pair($.String, a))],
+      function(strMap) {
+        return Object.keys(strMap).map(function(k) { return [k, strMap[k]]; });
+      });
+
   //. ### Number
 
   //# negate :: ValidNumber -> ValidNumber

diff --git a/test/keys.js b/test/keys.js
@@ -0,0 +1,59 @@
+'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({}), []);
+    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/pairs.js b/test/pairs.js
@@ -0,0 +1,63 @@
+'use strict';
+
+var throws = require('assert').throws;
+
+var eq = require('./utils').eq;
+var errorEq = require('./utils').errorEq;
+var S = require('..');
+
+
+describe('toPairs', function() {
+
+  var comparePairsAsc = function(a, b) {
+    return a[0] < b[0] ? -1 : a[0] > b[0] ? 1 : 0;
+  };
+
+  it('is a unary function', function() {
+    eq(typeof S.pairs, 'function');
+    eq(S.pairs.length, 1);
+  });
+
+  it('type checks its arguments', function() {
+    throws(function() { S.pairs('xxx'); },
+           errorEq(TypeError,
+                   'Invalid value\n' +
+                   '\n' +
+                   'pairs :: StrMap a -> Array (Pair String 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.pairs({a: '1', b: 2, c: '3'}); },
+           errorEq(TypeError,
+                   'Type-variable constraint violation\n' +
+                   '\n' +
+                   'pairs :: StrMap a -> Array (Pair String 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 with the key value pairs of each property of the object', function() {
+    eq(S.pairs({}), []);
+    eq(S.pairs({a: 1, b: 2, c: 3}).sort(comparePairsAsc), [['a', 1], ['b', 2], ['c', 3]]);
+  });
+
+  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.pairs(obj).sort(comparePairsAsc), [['c', 3], ['d', 4]]);
+  });
+
+});
diff --git a/test/values.js b/test/values.js
@@ -0,0 +1,59 @@
+'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({}), []);
+    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]);
+  });
+
+});