不能断更...
逆波兰表达式求值
1 |
// 计算逆波兰表达式 |
–EOF–
协议前缀
1 |
import Foundation |
–EOF–
Vapor最简单的服务器
Package.swift
// swift-tools-version:5.1
// The swift-tools-version declares the minimum version of Swift required to build this package.
import PackageDescription
let package = Package(
name: "HelloWorld",
dependencies: [
// Dependencies declare other packages that this package depends on.
.package(url: "https://github.com/vapor/vapor.git", from: "4.0.0-alpha.2"),
],
targets: [
// Targets are the basic building blocks of a package. A target can define a module or a test suite.
// Targets can depend on other targets in this package, and on products in packages which this package depends on.
.target(
name: "HelloWorld",
dependencies: ["Vapor"]),
.testTarget(
name: "HelloWorldTests",
dependencies: ["HelloWorld"]),
]
)main.swift
import Vapor
let app = Application(environment: try .detect()) { (service) in
service.extend(Routes.self) { (routes, container) in
routes.get("hello") { (req) -> String in
"Hello World!"
}
}
}
try app.run()–EOF–
Swift 属性绑定
class Person { }
extension Person {
private static var age_key = false //占一个字节,省空间
private static var weight_key = false //占一个字节,省空间
// private static var age_key1: Void? //这种方式也是可以的
// private static var weight_key1: Void?
var age: Int {
get {
objc_getAssociatedObject(self, &Self.age_key) as! Int
}
set {
// self abc 都相当于是key
objc_setAssociatedObject(self, &Self.age_key, newValue, objc_AssociationPolicy.OBJC_ASSOCIATION_ASSIGN)
}
}
var weight: Int {
get {
objc_getAssociatedObject(self, &Self.weight_key) as! Int
}
set {
// self abc 都相当于是key
objc_setAssociatedObject(self, &Self.weight_key, newValue, objc_AssociationPolicy.OBJC_ASSOCIATION_ASSIGN)
}
}
}
var p = Person()
p.age = 10
print(p.age)
p.weight = 50
print(p.weight)–EOF–
Swift重命名C函数
Test.h
#ifndef Test_h
#define Test_h
#include <stdio.h>
int sum(int v1, int v2);
#endif /* Test_h */Test.c
#include "Test.h"
int sum(int v1, int v2) {
return v1 + v2;
}main.swift
// 重命名c函数
@_silgen_name("sum")
func swift_sum(_ v1: Int32, _ v2: Int32) -> Int32
print(swift_sum(1, 2))–EOF–
Custom expression pattern
// 自定义表达式模式
struct Student {
var score = 0, name = ""
/// pattern: case 后面内容
/// value: switch 后面内容
static func ~=(pattern: Int, value: Student) -> Bool {
return value.score >= pattern
}
static func ~=(pattern: Range<Int>, value: Student) -> Bool {
return pattern.contains(value.score)
}
static func ~=(pattern: ClosedRange<Int>, value: Student) -> Bool {
return pattern.contains(value.score)
}
}
var stu = Student(score: 75, name: "Tom")
switch stu {
case 100:
print(">=100")
case 90:
print(">=90")
case 80..<90:
print("[80, 90]")
case 60...79:
print("[60, 79]")
case 0:
print(">=0")
default:
break
}
extension String {
static func ~=(pattern: (String) -> String, value: String) -> Bool {
return pattern(value)
}
}
func hasPrefix(_ prefix: String) -> ((String) -> Bool) {
return { $0.hasPrefix(prefix) }
}
func hasSuffix(_ suffix: String) -> ((String) -> Bool) {
return { $0.hasSuffix(suffix) }
}
var fn = hasPrefix("123")
print(fn("123456"))
var str = "123456"
switch str {
case hasPrefix("123"), hasSuffix("456"):
print("123开头")
print("456结尾")
default:
break
}
func isEven(_ i: Int) -> Bool {
return i % 2 == 0
}
func isOdd(_ i: Int) -> Bool {
return i % 2 != 0
}
extension Int {
static func ~=(pattern: (Int) -> Bool, value: Int) -> Bool {
return pattern(value)
}
}
var age = 9
switch age {
case isEven: //函数匹配,函数类型
print(age,"是个偶数")
case isOdd:
print(age,"是个奇数")
default:
break
}–EOF–