[update built-in class] update Range class and it's method.

vm/core.c

@@ -1213,6 +1213,71 @@ static bool primMapValueIteratorValue(VM *vm, Value *args) {
     RET_VALUE(entry->value)
 }
 
+//objRange.from：返回range的from
+static bool primRangeFrom(VM *vm UNUSED, Value *args) {
+    RET_NUM(VALUE_TO_OBJRANGE(args[0])->from)
+}
+
+//objRange.to：返回range的to
+static bool primRangeTo(VM *vm UNUSED, Value *args) {
+    RET_NUM(VALUE_TO_OBJRANGE(args[0])->to)
+}
+
+//objRange.min：返回range中from和to较小的值
+static bool primRangeMin(VM *vm UNUSED, Value *args) {
+    ObjRange *objRange = VALUE_TO_OBJRANGE(args[0]);
+    RET_NUM(fmin(objRange->from, objRange->to))
+}
+
+//objRange.max：返回range中from和to较大的值
+static bool primRangeMax(VM *vm UNUSED, Value *args) {
+    ObjRange *objRange = VALUE_TO_OBJRANGE(args[0]);
+    RET_NUM(fmax(objRange->from, objRange->to))
+}
+
+//objRange.iterate(_)：迭代range中的值，并不索引
+static bool primRangeIterate(VM *vm, Value *args) {
+    ObjRange *objRange = VALUE_TO_OBJRANGE(args[0]);
+
+    //若未提供iter说明是第一次迭代，因此返回range->from
+    if (VALUE_IS_NULL(args[1]))
+        RET_NUM(objRange->from)
+
+    //迭代器必须是数字
+    if (!validateNum(vm, args[1]))
+        return false;
+    double iter = VALUE_TO_NUM(args[1]);
+
+    //若是正方向
+    if (objRange->from < objRange->to) {
+        iter++;
+        if (iter > objRange->to)
+            RET_FALSE
+    } else { //若是反向迭代
+        iter--;
+        if (iter < objRange->to)
+            RET_FALSE
+    }
+    RET_NUM(iter)
+}
+
+//objRange.iteratorValue(_)：range的迭代就是range中从from到to之间的值，因此直接返回迭代器就是range的值
+static bool primRangeIteratorValue(VM *vm UNUSED, Value *args) {
+    ObjRange *objRange = VALUE_TO_OBJRANGE(args[0]);
+    double value = VALUE_TO_NUM(args[1]);
+
+    //确保args[1]在from到to的范围中
+    //若是正方向
+    if (objRange->from < objRange->to) {
+        if (value >= objRange->from && value <= objRange->to)
+            RET_VALUE(args[1])
+    } else { //若是负方向
+        if (value <= objRange->from && value >= objRange->to)
+            RET_VALUE(args[1])
+    }
+    RET_FALSE
+}
+
 //从modules中获取名为moduleName的模块
 static ObjModule *getModule(VM *vm, Value moduleName) {
     Value value = mapGet(vm->allModules, moduleName);
@@ -1507,4 +1572,13 @@ void buildCore(VM *vm) {
     PRIM_METHOD_BIND(vm->mapClass, "iterate_(_)", primMapIterate)
     PRIM_METHOD_BIND(vm->mapClass, "keyIteratorValue_(_)", primMapKeyIteratorValue)
     PRIM_METHOD_BIND(vm->mapClass, "valueIteratorValue_(_)", primMapValueIteratorValue)
+
+    //绑定Range类
+    vm->rangeClass = VALUE_TO_CLASS(getCoreClassValue(coreModule, "Range"));
+    PRIM_METHOD_BIND(vm->rangeClass, "from", primRangeFrom)
+    PRIM_METHOD_BIND(vm->rangeClass, "to", primRangeTo)
+    PRIM_METHOD_BIND(vm->rangeClass, "min", primRangeMin)
+    PRIM_METHOD_BIND(vm->rangeClass, "max", primRangeMax)
+    PRIM_METHOD_BIND(vm->rangeClass, "iterate(_)", primRangeIterate)
+    PRIM_METHOD_BIND(vm->rangeClass, "iteratorValue(_)", primRangeIteratorValue)
 }