go语言编程实现递归函数示例详解

//fORMats according to a format specifier and writes to standard output.
printf(string format, any ...a){}
//formats according to a format specifier and returns the resulting string.
string sprintf(string format, any ...a){}

printf("hello %s ","123");
printf("hello-%s-%s ","123","abc");
printf("hello-%s-%d ","123",123);
string format = "this is %s ";
printf(format, "gscript");
string s = sprintf("nice to meet %s", "you");
assertEqual(s,"nice to meet you");

int add(string s, int ...num){
	println(s);
	int sum = 0;
	for(int i=0;i<len(num);i++){
		int v = num[i];
		sum = sum+v;
	}
	return sum;
}
int x = add("abc", 1,2,3,4);
println(x);
assertEqual(x, 10);

// appends "v" to the end of a array "a"
append(any[] a, any v){}

// Before
int[] a={1,2,3};
println(a);
println();
a = append(a,4);
println(a);
// Output: [1 2 3 4]
// Now
int[] a={1,2,3};
println(a);
println();
append(a,4);
int b = a[3];
assertEqual(4, b);
println(a);
// Output: [1 2 3 4]

a+2;
b+c;

1:0: undefined: a
2:0: undefined: b
2:2: undefined: c

class T{}
class T{}
// output:
2:0: class T redeclared in this block

int num(int x,int y){
	if (y==1 || y ==x) {
		return 1;
	}
	int v1 = num(x - 1, y - 1);
	return c;
}

int num(int x,int y){
	if (y==1 || y ==x) {
		return 1;
	}
    int v1 = num(x - 1, y - 1);
    int v2 = num(x - 1, y);
	int c = v1+v2;
    // int c = num(x - 1, y - 1)+num(x - 1, y);
	return c;
}
printTriangle(int row){
	for (int i = 1; i <= row; i++) {
        for (int j = 1; j <= row - i; j++) {
           print(" ");
        }
        for (int j = 1; j <= i; j++) {
            print(num(i, j) + " ");
        }
        println("");
    }
}
printTriangle(7);
// output:
      1 
     1 1 
    1 2 1 
   1 3 3 1 
  1 4 6 4 1 
 1 5 10 10 5 1 
1 6 15 20 15 6 1 

int num(int x,int y){
	if (y==1 || y ==x) {
		return 1;
	}
	int v1 = num(x - 1, y - 1);
	return c;
}

int f1(int a){
	if (a==10){
		return 10;
	}
	println("abc");
}

// 在 return 的时候递归向上扫描所有的 Block，并打上标记，用于后面执行 return 的时候直接返回。
func (v *Visitor) scanBlockStatementCtx(tree antlr.ParseTree, value interface{}) {
	context, ok := tree.(*parser.BlockContext)
	if ok {
		if v.blockCtx2Mark == nil {
			v.blockCtx2Mark = make(map[*parser.BlockContext]interface{})
		}
		v.blockCtx2Mark[context] = value
	}
	if tree.GetParent() != nil {
		v.scanBlockStatementCtx(tree.GetParent().(antlr.ParseTree), value)
	}
}