LibStack.sol¶
LibStack提供了栈数据结构。
使用方法¶
首先需要通过import引入LibStack类库，然后通过”.”进行方法调用，如下为调用LibStack方法的例子：
pragma solidity >=0.4.24 <0.6.11;
import "./LibStack.sol";
contract Test {
using LibStack for LibStack.Stack;
LibStack.Stack private stack;
function f() public returns(bytes32, uint) {
stack.push(bytes32(uint(1)));
stack.push(bytes32(uint(2)));
bytes32 pop = stack.pop();//Expect to be 2
uint size = stack.getSize();//Expected to be 1
return (pop, size);
}
}
API列表¶
| 编号 | API | API描述 |
|---|---|---|
| 1 | push(Stack storage self, bytes32 data) internal | 压入一个元素 |
| 2 | pop(Stack storage self) internal returns(bytes32) | 弹出一个元素 |
| 3 | peek(Stack storage self) internal view returns(bytes32) | 查询栈顶元素 |
| 4 | getSize(Stack storage self) internal view returns(uint256) | 获取栈元素数 |
API详情¶
1. push 函数¶
压入一个元素
参数¶
- Stack：栈
- bytes32: 元素
返回值¶
实例¶
pragma solidity >=0.4.24 <0.6.11;
import "./LibStack.sol";
contract Test {
using LibStack for LibStack.Stack;
LibStack.Stack private stack;
function f() public returns(uint ) {
stack.push(bytes32(uint(2)));
uint size = stack.getSize();//Expected to be 1
return size;
}
}
2. pop 函数¶
弹出一个元素
参数¶
- Stack: 栈
返回值¶
- bytes32：栈顶元素值
实例¶
pragma solidity >=0.4.24 <0.6.11;
import "./LibStack.sol";
contract Test {
using LibStack for LibStack.Stack;
LibStack.Stack private stack;
function f() public returns(bytes32, uint) {
stack.push(bytes32(uint(1)));
stack.push(bytes32(uint(2)));
bytes32 pop = stack.pop();//Expect to be 2
uint size = stack.getSize();//Expected to be 1
return (pop, size);
}
}
3. peek 函数¶
查询栈顶元素
参数¶
- Stack: 栈
返回值¶
- bytes32:栈顶元素值
实例¶
pragma solidity >=0.4.24 <0.6.11;
import "./LibStack.sol";
contract Test {
using LibStack for LibStack.Stack;
LibStack.Stack private stack;
function f() public returns(bytes32, uint) {
stack.push(bytes32(uint(1)));
stack.push(bytes32(uint(2)));
bytes32 top = stack.peek();//Expect to be 2
uint size = stack.getSize();//Expected to be 2
return (top, size);
}
}