Add Decimal.isDecimal and config reset

decimal.d.ts

@@ -76,6 +76,7 @@ interface DecimalConfig {
 
   // Requires `toFormat` <https://github.com/MikeMcl/toFormat>.
   format?: DecimalFormat;
+  defaults?: boolean;
 }
 
 // Requires `toFormat`.
@@ -92,6 +93,7 @@ export declare class Decimal {
   readonly d: number[];
   readonly e: number;
   readonly s: number;
+  private readonly name: string;
 
   constructor(n: DecimalValue);
 
@@ -285,6 +287,7 @@ export declare class Decimal {
   static exp(n: DecimalValue): Decimal
   static floor(n: DecimalValue): Decimal
   static hypot(...n: DecimalValue[]): Decimal
+  static isDecimal(object: any): boolean
   static ln(n: DecimalValue): Decimal
   static log(n: DecimalValue, base?: DecimalValue): Decimal
   static log2(n: DecimalValue): Decimal

decimal.js

@@ -34,7 +34,7 @@
 
 
     // The initial configuration properties of the Decimal constructor.
-    Decimal = {
+    DEFAULTS = {
 
       // These values must be integers within the stated ranges (inclusive).
       // Most of these values can be changed at run-time using the `Decimal.config` method.
@@ -99,7 +99,7 @@
   // ----------------------------------- END OF EDITABLE DEFAULTS ------------------------------- //
 
 
-    inexact, noConflict, quadrant,
+    Decimal, inexact, noConflict, quadrant,
     external = true,
 
     decimalError = '[DecimalError] ',
@@ -123,7 +123,7 @@
     PI_PRECISION = PI.length - 1,
 
     // Decimal.prototype object
-    P = {};
+    P = { name: '[object Decimal]' };
 
 
   // Decimal prototype methods
@@ -4160,6 +4160,7 @@
    *   minE       {number}
    *   modulo     {number}
    *   crypto     {boolean|number}
+   *   defaults   {true}
    *
    * E.g. Decimal.config({ precision: 20, rounding: 4 })
    *
@@ -4167,6 +4168,7 @@
   function config(obj) {
     if (!obj || typeof obj !== 'object') throw Error(decimalError + 'Object expected');
     var i, p, v,
+      useDefaults = obj.defaults === true,
       ps = [
         'precision', 1, MAX_DIGITS,
         'rounding', 0, 8,
@@ -4178,13 +4180,15 @@
       ];
 
     for (i = 0; i < ps.length; i += 3) {
-      if ((v = obj[p = ps[i]]) !== void 0) {
+      if (p = ps[i], useDefaults) this[p] = DEFAULTS[p];
+      if ((v = obj[p]) !== void 0) {
         if (mathfloor(v) === v && v >= ps[i + 1] && v <= ps[i + 2]) this[p] = v;
         else throw Error(invalidArgument + p + ': ' + v);
       }
     }
 
-    if ((v = obj[p = 'crypto']) !== void 0) {
+    if (p = 'crypto', useDefaults) this[p] = DEFAULTS[p];
+    if ((v = obj[p]) !== void 0) {
       if (v === true || v === false || v === 0 || v === 1) {
         if (v) {
           if (typeof crypto != 'undefined' && crypto &&
@@ -4327,6 +4331,7 @@
 
     Decimal.config = Decimal.set = config;
     Decimal.clone = clone;
+    Decimal.isDecimal = isDecimalInstance;
 
     Decimal.abs = abs;
     Decimal.acos = acos;
@@ -4367,8 +4372,10 @@
 
     if (obj === void 0) obj = {};
     if (obj) {
-      ps = ['precision', 'rounding', 'toExpNeg', 'toExpPos', 'maxE', 'minE', 'modulo', 'crypto'];
+      if (obj.defaults !== true) {
-      for (i = 0; i < ps.length;) if (!obj.hasOwnProperty(p = ps[i++])) obj[p] = this[p];
+        ps = ['precision', 'rounding', 'toExpNeg', 'toExpPos', 'maxE', 'minE', 'modulo', 'crypto'];
+        for (i = 0; i < ps.length;) if (!obj.hasOwnProperty(p = ps[i++])) obj[p] = this[p];
+      }
     }
 
     Decimal.config(obj);
@@ -4445,6 +4452,16 @@
   }
 
 
+  /*
+   * Return true if object is a Decimal instance (where Decimal is any Decimal constructor),
+   * otherwise return false.
+   *
+   */
+  function isDecimalInstance(obj) {
+    return obj instanceof Decimal || obj && obj.name === '[object Decimal]' || false;
+  }
+
+
   /*
    * Return a new Decimal whose value is the natural logarithm of `x`, rounded to `precision`
    * significant digits using rounding mode `rounding`.
@@ -4775,7 +4792,7 @@
 
 
   // Create and configure initial Decimal constructor.
-  Decimal = clone(Decimal);
+  Decimal = clone(DEFAULTS);
 
   Decimal['default'] = Decimal.Decimal = Decimal;
 

decimal.mjs

@@ -25,14 +25,14 @@ var EXP_LIMIT = 9e15,                      // 0 to 9e15
   NUMERALS = '0123456789abcdef',
 
   // The natural logarithm of 10 (1025 digits).
-  ln10 = '2.3025850929940456840179914546843642076011014886287729760333279009675726096773524802359972050895982983419677840422862486334095254650828067566662873690987816894829072083255546808437998948262331985283935053089653777326288461633662222876982198867465436674744042432743651550489343149393914796194044002221051017141748003688084012647080685567743216228355220114804663715659121373450747856947683463616792101806445070648000277502684916746550586856935673420670581136429224554405758925724208241314695689016758940256776311356919292033376587141660230105703089634572075440370847469940168269282808481184289314848524948644871927809676271275775397027668605952496716674183485704422507197965004714951050492214776567636938662976979522110718264549734772662425709429322582798502585509785265383207606726317164309505995087807523710333101197857547331541421808427543863591778117054309827482385045648019095610299291824318237525357709750539565187697510374970888692180205189339507238539205144634197265287286965110862571492198849978748873771345686209167058',
+  LN10 = '2.3025850929940456840179914546843642076011014886287729760333279009675726096773524802359972050895982983419677840422862486334095254650828067566662873690987816894829072083255546808437998948262331985283935053089653777326288461633662222876982198867465436674744042432743651550489343149393914796194044002221051017141748003688084012647080685567743216228355220114804663715659121373450747856947683463616792101806445070648000277502684916746550586856935673420670581136429224554405758925724208241314695689016758940256776311356919292033376587141660230105703089634572075440370847469940168269282808481184289314848524948644871927809676271275775397027668605952496716674183485704422507197965004714951050492214776567636938662976979522110718264549734772662425709429322582798502585509785265383207606726317164309505995087807523710333101197857547331541421808427543863591778117054309827482385045648019095610299291824318237525357709750539565187697510374970888692180205189339507238539205144634197265287286965110862571492198849978748873771345686209167058',
 
   // Pi (1025 digits).
-  pi = '3.1415926535897932384626433832795028841971693993751058209749445923078164062862089986280348253421170679821480865132823066470938446095505822317253594081284811174502841027019385211055596446229489549303819644288109756659334461284756482337867831652712019091456485669234603486104543266482133936072602491412737245870066063155881748815209209628292540917153643678925903600113305305488204665213841469519415116094330572703657595919530921861173819326117931051185480744623799627495673518857527248912279381830119491298336733624406566430860213949463952247371907021798609437027705392171762931767523846748184676694051320005681271452635608277857713427577896091736371787214684409012249534301465495853710507922796892589235420199561121290219608640344181598136297747713099605187072113499999983729780499510597317328160963185950244594553469083026425223082533446850352619311881710100031378387528865875332083814206171776691473035982534904287554687311595628638823537875937519577818577805321712268066130019278766111959092164201989380952572010654858632789',
+  PI = '3.1415926535897932384626433832795028841971693993751058209749445923078164062862089986280348253421170679821480865132823066470938446095505822317253594081284811174502841027019385211055596446229489549303819644288109756659334461284756482337867831652712019091456485669234603486104543266482133936072602491412737245870066063155881748815209209628292540917153643678925903600113305305488204665213841469519415116094330572703657595919530921861173819326117931051185480744623799627495673518857527248912279381830119491298336733624406566430860213949463952247371907021798609437027705392171762931767523846748184676694051320005681271452635608277857713427577896091736371787214684409012249534301465495853710507922796892589235420199561121290219608640344181598136297747713099605187072113499999983729780499510597317328160963185950244594553469083026425223082533446850352619311881710100031378387528865875332083814206171776691473035982534904287554687311595628638823537875937519577818577805321712268066130019278766111959092164201989380952572010654858632789',
 
 
   // The initial configuration properties of the Decimal constructor.
-  defaults = {
+  DEFAULTS = {
 
     // These values must be integers within the stated ranges (inclusive).
     // Most of these values can be changed at run-time using the `Decimal.config` method.
@@ -97,7 +97,7 @@ var EXP_LIMIT = 9e15,                      // 0 to 9e15
 // ----------------------------------- END OF EDITABLE DEFAULTS ------------------------------- //
 
 
-  Decimal, LN10, PI, inexact, quadrant,
+  Decimal, inexact, quadrant,
   external = true,
 
   decimalError = '[DecimalError] ',
@@ -117,11 +117,11 @@ var EXP_LIMIT = 9e15,                      // 0 to 9e15
   LOG_BASE = 7,
   MAX_SAFE_INTEGER = 9007199254740991,
 
-  LN10_PRECISION = ln10.length - 1,
+  LN10_PRECISION = LN10.length - 1,
-  PI_PRECISION = pi.length - 1,
+  PI_PRECISION = PI.length - 1,
 
   // Decimal.prototype object
-  P = {};
+  P = { name: '[object Decimal]' };
 
 
 // Decimal prototype methods
@@ -4158,6 +4158,7 @@ function ceil(x) {
  *   minE       {number}
  *   modulo     {number}
  *   crypto     {boolean|number}
+ *   defaults   {true}
  *
  * E.g. Decimal.config({ precision: 20, rounding: 4 })
  *
@@ -4165,6 +4166,7 @@ function ceil(x) {
 function config(obj) {
   if (!obj || typeof obj !== 'object') throw Error(decimalError + 'Object expected');
   var i, p, v,
+    useDefaults = obj.defaults === true,
     ps = [
       'precision', 1, MAX_DIGITS,
       'rounding', 0, 8,
@@ -4176,13 +4178,15 @@ function config(obj) {
     ];
 
   for (i = 0; i < ps.length; i += 3) {
-    if ((v = obj[p = ps[i]]) !== void 0) {
+    if (p = ps[i], useDefaults) this[p] = DEFAULTS[p];
+    if ((v = obj[p]) !== void 0) {
       if (mathfloor(v) === v && v >= ps[i + 1] && v <= ps[i + 2]) this[p] = v;
       else throw Error(invalidArgument + p + ': ' + v);
     }
   }
 
-  if ((v = obj[p = 'crypto']) !== void 0) {
+  if (p = 'crypto', useDefaults) this[p] = DEFAULTS[p];
+  if ((v = obj[p]) !== void 0) {
     if (v === true || v === false || v === 0 || v === 1) {
       if (v) {
         if (typeof crypto != 'undefined' && crypto &&
@@ -4325,6 +4329,7 @@ function clone(obj) {
 
   Decimal.config = Decimal.set = config;
   Decimal.clone = clone;
+  Decimal.isDecimal = isDecimalInstance;                          
 
   Decimal.abs = abs;
   Decimal.acos = acos;
@@ -4365,8 +4370,10 @@ function clone(obj) {
 
   if (obj === void 0) obj = {};
   if (obj) {
-    ps = ['precision', 'rounding', 'toExpNeg', 'toExpPos', 'maxE', 'minE', 'modulo', 'crypto'];
+    if (obj.defaults !== true) {
-    for (i = 0; i < ps.length;) if (!obj.hasOwnProperty(p = ps[i++])) obj[p] = this[p];
+      ps = ['precision', 'rounding', 'toExpNeg', 'toExpPos', 'maxE', 'minE', 'modulo', 'crypto'];
+      for (i = 0; i < ps.length;) if (!obj.hasOwnProperty(p = ps[i++])) obj[p] = this[p];
+    }
   }
 
   Decimal.config(obj);
@@ -4443,6 +4450,16 @@ function hypot() {
 }
 
 
+/*
+ * Return true if object is a Decimal instance (where Decimal is any Decimal constructor),
+ * otherwise return false.
+ *
+ */
+function isDecimalInstance(obj) {
+  return obj instanceof Decimal || obj && obj.name === '[object Decimal]' || false;
+}
+
+
 /*
  * Return a new Decimal whose value is the natural logarithm of `x`, rounded to `precision`
  * significant digits using rounding mode `rounding`.
@@ -4773,12 +4790,12 @@ function trunc(x) {
 
 
 // Create and configure initial Decimal constructor.
-Decimal = clone(defaults);
+Decimal = clone(DEFAULTS);
 
 Decimal['default'] = Decimal.Decimal = Decimal;
 
 // Create the internal constants from their string values.
-LN10 = new Decimal(ln10);
+LN10 = new Decimal(LN10);
-PI = new Decimal(pi);
+PI = new Decimal(PI);
 
 export default Decimal;

doc/API.html

@@ -83,6 +83,7 @@ li span{float:right;margin-right:10px;color:#c0c0c0}
       <li><a href="#Dexp"       >exp</a></li>
       <li><a href="#Dfloor"     >floor</a></li>
       <li><a href="#Dhypot"     >hypot</a></li>
+      <li><a href="#DisDecimal" >isDecimal</a></li>
       <li><a href="#Dln"        >ln</a></li>
       <li><a href="#Dlog"       >log</a></li>
       <li><a href="#Dlog2"      >log2</a></li>
@@ -195,9 +196,9 @@ li span{float:right;margin-right:10px;color:#c0c0c0}
 
     <a href="#instance-properties">Properties</a>
     <ul>
-      <li><a href="#digits"  >d</a><span>digits</span></li>
+      <li><a href="#digits"   >d</a><span>digits</span></li>
-      <li><a href="#exponent">e</a><span>exponent</span></li>
+      <li><a href="#exponent" >e</a><span>exponent</span></li>
-      <li><a href="#sign"    >s</a><span>sign</span></li>
+      <li><a href="#sign"     >s</a><span>sign</span></li>
     </ul>
 
     <a href="#zero-nan-infinity">Zero, NaN &amp; Infinity</a>
@@ -446,24 +447,32 @@ a.equals(b)                    // true</pre>
       settings as <code>this</code> Decimal constructor if <code>object</code> is omitted.
     </p>
     <pre>Decimal.set({ precision: 5 })
-D9 = Decimal.clone({ precision: 9 })
+Decimal9 = Decimal.clone({ precision: 9 })
 
 a = new Decimal(1)
-b = new D9(1)
+b = new Decimal9(1)
 
 a.div(3)                           // 0.33333
 b.div(3)                           // 0.333333333
 
-// D9 = Decimal.clone({ precision: 9 }) is equivalent to:
+// Decimal9 = Decimal.clone({ precision: 9 }) is equivalent to:
-D9 = Decimal.clone()
+Decimal9 = Decimal.clone()
-D9.set({ precision: 9 })</pre>
+Decimal9.set({ precision: 9 })</pre>
+    <p>
+      If <code>object</code> has a <code>'defaults'</code> property with value <code>true</code>
+      then the new constructor will use the default configuration.
+    </p>
+    <pre>
+D1 = Decimal.clone({ defaults: true })
+
+// Use the defaults except for precision
+D2 = Decimal.clone({ defaults: true, precision: 50 })</pre>
     <p>
       It is not inefficient in terms of memory usage to use multiple Decimal constructors as
       functions are shared between them.
     </p>
 
 
-
     <h5 id="Dcos">cos<code class='inset'>.cos(x) <i>&rArr; Decimal</i></code></h5>
     <p><code>x</code>: <i>number|string|Decimal</i></p>
     <p>See <code><a href='#cos'>cosine</a></code>.</p>
@@ -537,6 +546,22 @@ a.equals(b)                    // true</pre>
 
 
 
+    <h5 id="DisDecimal">
+      isDecimal<code class='inset'>.isDecimal(object) <i>&rArr; boolean</i></code>
+    </h5>
+    <p><code>object</code>: <i>any</i></p>
+    <p>
+      Returns <code>true</code> if <code>object</code> is a Decimal instance (where Decimal is any
+      Decimal constructor), or <code>false</code> if it is not.
+    </p>
+    <pre>a = new Decimal(1)
+b = {}
+a instanceof Decimal           // true
+Decimal.isDecimal(a)           // true
+Decimal.isDecimal(b)           // false</pre>
+
+
+
     <h5 id="Dlog">log<code class='inset'>.log(x [, base]) <i>&rArr; Decimal</i></code></h5>
     <p>
       <code>x</code>: <i>number|string|Decimal</i><br />
@@ -720,6 +745,10 @@ a.equals(b)                    // true</pre>
       The values of the configuration object properties are checked for validity and then stored as
       equivalently-named properties of <code>this</code> Decimal constructor.
     </p>
+    <p>
+      If <code>object</code> has a <code>'defaults'</code> property with value <code>true</code>
+      then any unspecified properties will be reset to their default values.
+    </p>
     <p>Throws on an invalid <code>object</code> or configuration property value.</p>
     <pre>
 // Defaults
@@ -732,7 +761,13 @@ Decimal.set({
     minE: -9e15,
     modulo: 1,
     crypto: false
-})</pre>
+})
+
+// Reset all properties to their default values
+Decimal.set({ defaults: true })
+
+// Set precision to 50 and all other properties to their default values
+Decimal.set({ precision: 50, defaults: true })</pre>
     <p>
       The properties of a Decimal constructor can also be set by direct assignment, but that will
       by-pass the validity checking that this method performs - this is not a problem if the user
@@ -2478,9 +2513,9 @@ x.valueOf()                              // '-0'</pre>
         <td><code>-1</code>, <code>1</code>, or <code>NaN</code></td>
       </tr>
     </table>
-    <p>The properties are best considered to be read-only.</p>
+    <p>All the properties are best considered to be read-only.</p>
     <p>
-      As with JavaScript numbers, the original exponent and fractional trailing zeros of a number
+      As with JavaScript numbers, the original exponent and fractional trailing zeros of a value
       are not preserved.
     </p>
     <pre>

test/modules/clone.js

@@ -105,5 +105,40 @@ T('clone', function () {
   t(new D8(1).constructor !== new D9(1).constructor);
 
   T.assertException(function () { Decimal.clone(null) }, "Decimal.clone(null)");
+
+  // defaults: true
+
+  Decimal.config({
+    precision: 100,
+    rounding: 2,
+    toExpNeg: -100,
+    toExpPos: 200,
+    defaults: true
+  });
+
+  t(Decimal.precision === 100);
+  t(Decimal.rounding === 2);
+  t(Decimal.toExpNeg === -100);
+  t(Decimal.toExpPos === 200);
+  t(Decimal.defaults === undefined);
+
+  D1 = Decimal.clone({ defaults: true });
+
+  t(D1.precision === 20);
+  t(D1.rounding === 4);
+  t(D1.toExpNeg === -7);
+  t(D1.toExpPos === 21);
+  t(D1.defaults === undefined);
+
+  D2 = Decimal.clone({ defaults: true, rounding: 5 });
+
+  t(D2.precision === 20);
+  t(D2.rounding === 5);
+  t(D2.toExpNeg === -7);
+  t(D2.toExpPos === 21);
+
+  D3 = Decimal.clone({ defaults: false });
+
+  t(D3.rounding === 2);
 });
 

test/modules/config.js

@@ -338,5 +338,36 @@ T('config', function () {
 
   t(9, {modulo: void 0});
 
+  // defaults
+
+  t = function (actual) {
+    T.assert(actual);
+  }
+
+  Decimal.config({
+    precision: 100,
+    rounding: 2,
+    toExpNeg: -100,
+    toExpPos: 200,
+  });
+
+  t(Decimal.precision === 100);
+
+  Decimal.config({ defaults: true });
+
+  t(Decimal.precision === 20);
+  t(Decimal.rounding === 4);
+  t(Decimal.toExpNeg === -7);
+  t(Decimal.toExpPos === 21);
+  t(Decimal.defaults === undefined);
+
+  Decimal.rounding = 3;
+
+  Decimal.config({ precision: 50, defaults: true });
+
+  t(Decimal.precision === 50);
+  t(Decimal.rounding === 4);
+
+  // Decimal.set is an alias for Decimal.config
   T.assertEqual(Decimal.set, Decimal.config);
 });

test/modules/isFiniteEtc.js

@@ -1,6 +1,6 @@
 if (typeof T === 'undefined') require('../setup');
 
-T('isFinite, isInteger, isNaN, isNegative, isZero', function () {
+T('isFinite, isInteger, isNaN, isNegative, isZero, isDecimal', function () {
 
   function t(actual) {
     T.assert(actual);
@@ -257,4 +257,22 @@ T('isFinite, isInteger, isNaN, isNegative, isZero', function () {
   t(!new Decimal('0.999999999999999999999').isInteger());
   t(new Decimal('4e4').isInteger());
   t(new Decimal('-4e4').isInteger());
+
+  // Decimal.isDecimal
+
+  t(Decimal.isDecimal(new Decimal(1)));
+  t(Decimal.isDecimal(new Decimal('-2.3')));
+  t(Decimal.isDecimal(new Decimal(NaN)));
+  t(Decimal.isDecimal(new Decimal('Infinity')));
+
+  t(!Decimal.isDecimal());
+  t(!Decimal.isDecimal(0));
+  t(!Decimal.isDecimal(1));
+  t(!Decimal.isDecimal('-2.3'));
+  t(!Decimal.isDecimal(NaN));
+  t(!Decimal.isDecimal(Infinity));
+  t(!Decimal.isDecimal(undefined));
+  t(!Decimal.isDecimal({}));
+  t(!Decimal.isDecimal({isDecimal: true}));
+  t(!Decimal.isDecimal(new Number(4)));
 });