v0.4.2-alpha

[Fix][Impl] 为了消除类构造带来的语法歧义，同时保持实现简洁和括号省略的语法，自此版本，引入了 `new` 操作符
            造成歧义的原方法：
                if a == A{}
            条件是 a == A，还是 a == A{} ?

            因此，现在使用 new a_struct{}来构造类
[Opti] 相较于 Fig v0.4.1-alpha版本，release O3同编译条件下
       Fib普通递归法性能提升 ~50%
       具体方式:
            增加了小整数优化，-128~127的整数现在会直接从IntPool获取而不是新构造
            ...忘了
[Fix] 类构造 shorthand模式忘写了，现在补上了
[Feat][Impl] 类型声明现在接受一个表达式，原为Identifier。实现 var start: time.Time = time.now() 的效果
             这是符合语法和语言特性的支持，类型为一等公民。类似Python的 <class 'type'>

[Impl] 修改了部分错误输出的细节

ExampleCodes/1-Variables.fig

@@ -10,4 +10,70 @@ invalid!
 */
 
 const Pi := 3.14; // recommended, auto detect type
-// equal -> const Pi: Double = 3.14;
+// equal -> const Pi: Double = 3.14;
+
+/*
+In fig, we have 13 builtin-type
+
+01  Any
+02  Null
+03  Int
+04  String
+05  Bool
+06  Double
+07  Function
+08  StructType
+09  StructInstance
+10  List
+11  Map
+12  Module
+13  InterfaceType
+
+3, 4, 5, 6, 10, 11 are initable
+
+value system:
+    object is immutable
+    (included basic types: Int, String...)
+
+    `variable` is a name, refers to an object
+    assignment is to bind name to value
+    
+    Example: var a := 10;
+
+    [name] 'a' ---> variable slot (name, declared type, access modifier, [value) ---> ObjectPtr ---> raw Object class
+               bind                                                              bind (shared_ptr)
+
+    For example:
+        var a := 10;
+        var b := 10;
+
+        `a` and `b` reference to the same object in memory
+
+        a = 20;
+
+        now a refers to a new object (20, Int)
+
+        what about complex types?
+        they actually have same behaviors with basic types
+
+        var a := [1, 2, 3, 4];
+        var b := a;
+
+        > a
+          [1, 2, 3, 4]
+        > b
+          [1, 2, 3, 4]
+        
+        set a[0] to 5
+
+        > a
+          [5, 2, 3, 4]
+        > b
+          [5, 2, 3, 4]
+
+        Why did such a result occur?
+    
+        " `a` and `b` reference to the same object in memory "
+
+        If you wish to obtain a copy, use List {a} to deeply copy it
+*/

ExampleCodes/SpeedTest/fibBenchmark.fig

@@ -0,0 +1,65 @@
+import std.io;
+import std.time;
+
+func benchmark(fn: Function, arg: Any) -> Null
+{
+    io.println("Testing fn:", fn, "with arg:", arg);
+    const start := time.now();
+    
+    const result := fn(arg);
+    
+    const end := time.now();
+    const duration := new time.Time{
+        end.since(start)
+    };
+    io.println("=" * 50);
+    io.println("fn returns:", result, "\n");
+    io.println("Cost:", duration.toSeconds(), "s");
+    io.println("     ", duration.toMillis(), "ms");
+}
+
+var memo := {};
+
+func fib_memo(x)
+{
+    if memo.contains(x)
+    {
+        return memo.get(x);
+    }
+    if x <= 1
+    {
+        memo[x] = x;
+        return x;
+    }
+    var result := fib_memo(x - 1) + fib_memo(x - 2);
+    memo[x] = result;
+    return result;
+}
+
+func fib_iter(n)
+{
+    var a := 0;
+    var b := 1;
+    for var i := 0; i < n; i = i + 1
+    {
+        var temp := a + b;
+        a = b;
+        b = temp;
+    }
+    return a;
+}
+
+func fib(x)
+{
+    if x <= 1
+    {
+        return x;
+    }
+    return fib(x - 1) + fib(x - 2);
+}
+
+const n := 28;
+
+benchmark(fib, n);
+benchmark(fib_memo, n);
+benchmark(fib_iter, n);