Add 'Array.slice' function, and its corresponding unit test.

All tests are passing!!!

Author: GuillermoHernan

TinyJS_Functions.cpp

@@ -254,52 +254,6 @@ Ref<JSValue> scArrayIndexOf(FunctionScope* pScope)
     }
     return jsInt(-1);
 }
-/*Ref<JSValue> scArrayContains(FunctionScope* pScope) {
-  Ref<JSValue>  obj = pScope->getParam("obj");
-  Ref<JSValue>  arr = pScope->getThis();
-  
-  if (!arr->isArray())
-      return jsFalse();
-
-  Ref<JSArray>  v = arr.staticCast();
-
-  while (v) {
-      if (v->var->equals(obj)) {
-        contains = true;
-        break;
-      }
-      v = v->nextSibling;
-  }
-
-  return jsFalse();
-}
-
-Ref<JSValue> scArrayRemove(FunctionScope* pScope) {
-  CScriptVar *obj = pScope->getParam("obj");
-  vector<int> removedIndices;
-  CScriptVarLink *v;
-  // remove
-  v = pScope->getThis()->firstChild;
-  while (v) {
-      if (v->var->equals(obj)) {
-        removedIndices.push_back(v->getIntName());
-      }
-      v = v->nextSibling;
-  }
-  // renumber
-  v = pScope->getThis()->firstChild;
-  while (v) {
-      int n = v->getIntName();
-      int newn = n;
-      for (size_t i=0;i<removedIndices.size();i++)
-        if (n>=removedIndices[i])
-          newn--;
-      if (newn!=n)
-        v->setIntName(newn);
-      v = v->nextSibling;
-  }
-}
- */
 
 Ref<JSValue>scArrayJoin(FunctionScope* pScope)
 {
@@ -322,6 +276,33 @@ Ref<JSValue>scArrayJoin(FunctionScope* pScope)
     return jsString(output.str());
 }
 
+/**
+ * Creates a 'alice' of the array. A contiguous subset of array elements
+ * defined by a initial index (included) and a final index (not included)
+ * @param pScope
+ * @return 
+ */
+Ref<JSValue>scArraySlice(FunctionScope* pScope)
+{
+    Ref<JSArray>    arr = pScope->getThis().staticCast<JSArray>();
+    auto            begin = pScope->getParam("begin");
+    auto            end = pScope->getParam("end");
+    const size_t    iBegin = begin->toInt32();
+    size_t          iEnd = arr->length();
+    
+    if (!end->isNull() && end->toInt32() >= 0)
+        iEnd = end->toInt32();
+    
+    iEnd = max (iEnd, iBegin);
+    
+    auto result = JSArray::create();
+    
+    for (size_t i = iBegin; i < iEnd; ++i)
+        result->push(arr->getAt(i));
+
+    return result;
+}
+
 // ----------------------------------------------- Register Functions
 
 Ref<JSObject> createClass(const char* className,
@@ -382,9 +363,8 @@ void registerFunctions(Ref<IScope> scope)
     addNative("function parseInt(str)", scIntegerParseInt, scope); // string to int
     addNative("function Integer.valueOf(str)", scIntegerValueOf, scope); // value of a single character
     addNative("function JSON.stringify(obj, replacer)", scJSONStringify, scope); // convert to JSON. replacer is ignored at the moment
-    // JSON.parse is left out as you can (unsafely!) use eval instead
-    //    addNative("function Array.contains(obj)", scArrayContains, scope);
-    //    addNative("function Array.remove(obj)", scArrayRemove, scope);
+    //TODO: Add JSON.parse()
+    addNative("function Array.prototype.slice(begin, end)", scArraySlice, scope);
     addNative("function Array.prototype.join(separator)", scArrayJoin, scope);
     addNative("function Array.prototype.push(x)", scArrayPush, scope);
     addNative("function Array.prototype.indexOf(searchElement, fromIndex)", scArrayIndexOf, scope);

tests/test029.js

@@ -1,7 +1,13 @@
-// test for array remove
+// test for array slice
 var a = [1,2,4,5,7];
 
-a.remove(2);
-a.remove(5);
+var b = a.slice(2);
+var c = a.slice(1,3);
+var d = a.slice(1, -3);
 
-result = a.length==3 && a[0]==1 && a[1]==4 && a[2]==7;
+
+assert (b.join() == "4,5,7", "wrong 'b' array: " + b.join());
+assert (c.join() == "2,4", "wrong 'c' array: " + c.join());
+assert (d.join() == "2,4,5,7", "wrong 'd' array: " + d.join());
+
+result = 1;