support synchronous call

.gitignore

@@ -2,3 +2,4 @@
 node_modules
 build
 lib
+*.tgz

.npmignore

@@ -0,0 +1,5 @@
+build
+.*
+*.yaml
+*.tgz
+lib

Readme.md

@@ -82,6 +82,27 @@ tulind.indicators.stoch.indicator([high, low, close], [5, 3, 3], function(err, r
 ```
 
 
+Examples of avoiding callbacks:
+
+``` js
+// Using indicator_sync
+const results = tulind.indicators.stoch.indicator_sync([high, low, close], [5, 3, 3]);
+console.log("Result of stochastic oscillator is:");
+console.log(results[0]);
+console.log(results[1]);
+```
+
+``` js
+// Using await
+(async ()=> {
+  const results = await tulind.indicators.stoch.indicator([high, low, close], [5, 3, 3]);
+  console.log("Result of stochastic oscillator is:");
+  console.log(results[0]);
+  console.log(results[1]);
+})();
+```
+
+
 It's also easy to discover argument types at run-time:
 
 ``` js

index.js

@@ -19,6 +19,13 @@ var make_call = function(ind) {
   };
 };
 
+var make_sync_call = function(ind) {
+  var index = ind.index;
+  return function(inputs, options) {
+    return tulind.callbyindex(index, inputs, options);
+  };
+};
+
 var make_start = function(ind) {
   var index = ind.index;
   return function(options) {
@@ -34,6 +41,7 @@ for (var key in indicators) {
   if (typeof ind.indicator == 'function') break;
 
   ind.indicator = make_call(ind);
+  ind.indicator_sync = make_sync_call(ind);
   ind.start = make_start(ind);
   delete ind.index;
 }

test.js

@@ -30,6 +30,8 @@ l.run("array dema", function() {
   tulind.indicators.dema.indicator([a], [5], function(err, results) {
     l.ok(equal(results[0], b));
   });
+  const results = tulind.indicators.dema.indicator_sync([a], [5]);
+  l.ok(equal(results[0], b));
 });
 
 l.run("array sma", function() {
@@ -63,12 +65,29 @@ l.run("array sma", function() {
       l.ok(equal(results[0], []));
     });
 
+    var results = tulind.indicators.sma.indicator_sync([a], [2]);
+    l.ok(equal(results[0], [1.5, 2.5, 3.5, 4.5, 5.5, 6.5, 7.5, 8.5, 9.5]));
+
+    results = tulind.indicators.sma.indicator_sync([a], [3]);
+    l.ok(equal(results[0], [2, 3, 4, 5, 6, 7, 8, 9]));
+
+    results = tulind.indicators.sma.indicator_sync([a], [4]);
+    l.ok(equal(results[0], [2.5, 3.5, 4.5, 5.5, 6.5, 7.5, 8.5]));
+
+    results = tulind.indicators.sma.indicator_sync([a], [10]);
+    l.ok(equal(results[0], [5.5]));
+
+    results = tulind.indicators.sma.indicator_sync([a], [11]);
+    l.ok(equal(results[0], []));
     //atoz page 207
     var c = [25,24.875,24.781,24.594,24.5,24.625,25.219,27.25];
     var b = [24.75,24.675,24.744,25.238];
     tulind.indicators.sma.indicator([c], [5], function(err, results) {
       l.ok(equal(results[0], b));
     });
+
+    results = tulind.indicators.sma.indicator_sync([c], [5]);
+    l.ok(equal(results[0], b));
 });
 
 
@@ -79,6 +98,9 @@ l.run("array ema", function() {
     tulind.indicators.ema.indicator([a], [5], function(err, results) {
       l.ok(equal(results[0], b));
     });
+
+    const results = tulind.indicators.ema.indicator_sync([a], [5]);
+    l.ok(equal(results[0], b));
 });
 
 
@@ -89,6 +111,9 @@ l.run("array tema", function() {
     tulind.indicators.tema.indicator([a], [5], function(err, results) {
       l.ok(equal(results[0], b));
     });
+
+    const results = tulind.indicators.tema.indicator_sync([a], [5]);
+    l.ok(equal(results[0], b));
 });
 
 l.run("array wilders", function() {
@@ -98,6 +123,9 @@ l.run("array wilders", function() {
     tulind.indicators.wilders.indicator([a], [5], function(err, results) {
       l.ok(equal(results[0], b));
     });
+
+    const results = tulind.indicators.wilders.indicator_sync([a], [5]);
+    l.ok(equal(results[0], b));
 });
 
 

tulind.cpp

@@ -89,9 +89,9 @@ NAN_METHOD(startbyindex) {
 
 
 NAN_METHOD(callbyindex) {
-
-    if (info.Length() != 4) {
-        Nan::ThrowTypeError("Wrong number of arguments. Expecting: index, inputs, options, and callback.");
+    bool synchronous_call = info.Length() == 3;
+    if (!synchronous_call && info.Length() != 4) {
+        Nan::ThrowTypeError("Wrong number of arguments. Expecting: index, inputs, options, and [callback].");
         return;
     }
 
@@ -110,8 +110,8 @@ NAN_METHOD(callbyindex) {
         return;
     }
 
-    if (!info[3]->IsFunction()) {
-        Nan::ThrowTypeError("Expecting last argument to be callback function.");
+    if (!synchronous_call && !info[3]->IsFunction()) {
+        Nan::ThrowTypeError("Expecting fourth argument to be callback function.");
         return;
     }
 
@@ -233,6 +233,16 @@ NAN_METHOD(callbyindex) {
         free(output_arr[i]);
     }
 
+    if (synchronous_call) {
+        if (cb_argv[0]->IsNull()) {
+            info.GetReturnValue().Set(cb_argv[1]);
+            return;
+        }
+        else {
+            Nan::ThrowError(cb_argv[0]);
+            return;
+        }
+    }
 
     v8::Local<v8::Function> callbackHandle = info[3].As<v8::Function>();
     Nan::AsyncResource cb("tulind-callback");