change dir struct and add some examples

Author: yjhmelody

README.md

@@ -1,3 +1,46 @@
 # lambda-language
 
-## The toy language is written by javascript(undone)
+## The toy language is written by javascript(basic now)
+
+### example
+
+```
+print_range = λ(a, b) if a <= b {
+                        print(a);
+                        if a + 1 <= b {
+                          print(", ");
+                          print_range(a + 1, b);
+                        } 
+                        else 
+                          println("");
+                      };
+print_range(1, 10);
+```
+output:
+```
+1, 2, 3, 4, 5, 6, 7, 8, 9, 10
+***Result: false
+```
+
+```
+cons = λ(a, b) λ(f) f(a, b);
+car = λ(cell) cell(λ(a, b) a);
+cdr = λ(cell) cell(λ(a, b) b);
+NIL = λ(f) f(NIL, NIL);
+
+x = cons(1, cons(2, cons(3, cons(4, cons(5, NIL)))));
+println(car(x));                      # 1
+println(car(cdr(x)));                 # 2
+println(car(cdr(cdr(x))));            # 3
+println(car(cdr(cdr(cdr(x)))));       # 4
+println(car(cdr(cdr(cdr(cdr(x))))));  # 5
+```
+output:
+```
+1
+2
+3
+4
+5
+***Result: false
+```