大跨度的日期 [英] Strideable Date

问题描述

我正在寻找一种以不同的增量跨越 Date 范围的好方法(秒数又称为 TimeInterval 或 DateComponents 又称为 .hour ， .minute )

I'm looking for cool ways to stride through Date ranges with different increments (either seconds aka TimeInterval or with DateComponents aka .hour, .minute)

import Foundation

extension Date: Strideable {
    // typealias Stride = SignedInteger // doesn't work (probably because declared in extension
    public func advanced(by n: Int) -> Date {
        self.addingTimeInterval(TimeInterval(n))
    }

    public func distance(to other: Date) -> Int {
        return Int(self.distance(to: other))
    }
}
let now = Date()

let dayAfterNow = Date().addingTimeInterval(86400)
let dateRange = now ... dayAfterNow
let dateArr : [Date] = Array(stride(from: now, to: dayAfterNow, by: 60)) // Solves my task but  not exactly how I wanted.
let formatter: DateFormatter = {
    let df = DateFormatter()
    df.timeStyle = .short
    return df }()
print (dateArr.prefix(7).map { formatter.string(from: $0) })

/// This hoever doesn't work
// There must be a way to make it work but couldn't figure it out for now
let errDateArr: [Date] = Array(dateRange)
// Error: Initializer 'init(_:)' requires that 'Date.Stride' (aka 'Double') conform to 'SignedInteger'

问题的第二部分是，我也想拥有类似的东西:

The second part of the question is that also i'd like to have something like:

var components = DateComponents()
components.hour = 8
components.minute = 0
let date = Calendar.current.date(from: components)
let dateByComponentArr : [Date] = Array(stride(from: now, to: dayAfterNow, by: components))

推荐答案

正如@Alexander所提到的那样，您不应该尝试将Date设置为Strideable，但是您可以实现自己的方法来生成接下来的n天，几小时或几分钟:

As already mentionerd by @Alexander you shouldn't try to conform Date to Strideable but you can implement your own methods to generate the next n days, hours or minutes:

extension Date {
    func year(using calendar: Calendar = .current) -> Int { calendar.component(.year, from: self) }
    func month(using calendar: Calendar = .current) -> Int { calendar.component(.month, from: self) }
    func day(using calendar: Calendar = .current) -> Int { calendar.component(.day, from: self) }
    func hour(using calendar: Calendar = .current) -> Int { calendar.component(.hour, from: self) }
    func minute(using calendar: Calendar = .current) -> Int { calendar.component(.minute, from: self) }
    func nextDays(n: Int, nth: Int = 1, using calendar: Calendar = .current) -> [Date] {
        let year  = self.year(using: calendar)
        let month = self.month(using: calendar)
        let day   = self.day(using: calendar)
        var days: [Date] = []
        for x in 0..<n where x.isMultiple(of: nth) {
            days.append(DateComponents(calendar: calendar, year: year, month: month, day: day + x, hour: 12).date!)

        }
        return days
    }
    func nextHours(n: Int, nth: Int = 1, using calendar: Calendar = .current) -> [Date] {
        let year  = self.year(using: calendar)
        let month = self.month(using: calendar)
        let day   = self.day(using: calendar)
        let hour   = self.hour(using: calendar)
        var hours: [Date] = []
        for x in 0..<n where x.isMultiple(of: nth) {
            hours.append(DateComponents(calendar: calendar, year: year, month: month, day: day, hour: hour + x).date!)

        }
        return hours
    }
    func nextMinutes(n: Int, nth: Int = 1, using calendar: Calendar = .current) -> [Date] {
        let year  = self.year(using: calendar)
        let month = self.month(using: calendar)
        let day   = self.day(using: calendar)
        let hour   = self.hour(using: calendar)
        let minute   = self.minute(using: calendar)
        var minutes: [Date] = []
        for x in 0..<n where x.isMultiple(of: nth) {
            minutes.append(DateComponents(calendar: calendar, year: year, month: month, day: day, hour: hour, minute: minute + x).date!)

        }
        return minutes
    }
}

---

extension Date {
    static let formatter: DateFormatter = {
        let formatter = DateFormatter()
        formatter.dateStyle = .short
        formatter.timeStyle = .short
        return formatter
    }()
}

---

Playgournd测试:

---

Playgournd testing:

let days = Date().nextDays(n: 10)
for day in days {
    print(Date.formatter.string(from: day))
}

let hours = Date().nextHours(n: 10)
for hour in hours {
    print(Date.formatter.string(from: hour))
}

let minutes = Date().nextMinutes(n: 10)
for minute in minutes {
    print(Date.formatter.string(from: minute))
}

这篇关于大跨度的日期的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！