#101 Add clamp method

test/modules/clamp.js

@@ -0,0 +1,49 @@
+if (typeof T === 'undefined') require('../setup');
+
+T('clamp', function () {
+
+  function t(x, min, max, expected) {
+    //T.assertEqual(expected, new Decimal(x).clampedTo(min, max).valueOf());
+    T.assertEqual(expected, new Decimal(x).clamp(min, max).valueOf());
+    //T.assertEqual(expected, Decimal.clamp(x, min, max).valueOf());
+  }
+
+  t('-0', '0', '0', '-0');
+  t('-0', '-0', '0', '-0');
+  t('-0', '0', '-0', '-0');
+  t('-0', '-0', '-0', '-0');
+  
+  t('0', '0', '0', '0');
+  t('0', '-0', '0', '0');
+  t('0', '0', '-0', '0');
+  t('0', '-0', '-0', '0');
+  
+  t(0, 0, 1, '0');
+  t(-1, 0, 1, '0');
+  t(-2, 0, 1, '0');
+  t(1, 0, 1, '1');
+  t(2, 0, 1, '1');
+  
+  t(0, 0, -1, 'NaN');
+  t(1, 1, 1, '1');
+  t(-1, 1, 1, '1');
+  t(-1, -1, 1, '-1');
+  t(1, 1, -1, 'NaN');
+  t(2, 1, 2, '2');
+  t(3, 1, 2, '2');
+  t(1, 0, 1, '1');
+  t(2, 0, 1, '1');
+  
+  t(Infinity, 0, 1, '1');
+  t(0, -Infinity, 0, '0');
+  t(-Infinity, 0, 1, '0');
+  t(-Infinity, -Infinity, Infinity, '-Infinity');
+  t(Infinity, -Infinity, Infinity, 'Infinity');
+  t(Infinity, Infinity, -Infinity, 'NaN');
+  t(0, Infinity, 0, 'NaN');
+  t(0, 1, Infinity, '1');
+  
+  t(0, NaN, 1, 'NaN');
+  t(0, 0, NaN, 'NaN');
+  t(NaN, 0, 1, 'NaN');
+});

test/test.html

@@ -28,6 +28,7 @@
     'atanh',
     'cbrt',
     'ceil',
+    'clamp',
     'clone',
     'cmp',
     'config',

test/test.js

@@ -15,6 +15,7 @@ console.log('\n Testing decimal.js\n');
   'atanh',
   'cbrt',
   'ceil',
+  'clamp',
   'clone',
   'cmp',
   'config',