moallemi / kotlin-date-range

Implementation of rangeTo operator for LocalDate and Date in kotlin

Kotlin Date Range

This is a tiny implementation of rangeTo operator for Date and LocalDate that makes the syntax for loop iteration and control flow statements safe and natural to read.

Installation

Add the kotlin-date-range to your dependencies section:

dependencies {
  implementation 'me.moallemi.tools:kotlin-date-range:1.0.0'
}

How to use

From Java SE 8 onwards, users are asked to migrate to java.time (JSR-310). For Android users, java.time is added in API level 26+. Projects needing to support lower API levels can use java.util.Date.

with java.time.LocalDate

Using rangeTo operator:

import me.moallemi.tools.daterange.localdate.rangeTo

val startDate = LocalDate.of(2020, 3, 22)
val endDate = LocalDate.of(2020, 4, 1)
for (date in startDate..endDate) {
    println(date)
}

Usage with step function:

import me.moallemi.tools.daterange.localdate.rangeTo

val startDate = LocalDate.of(2020, 3, 22)
val endDate = LocalDate.of(2020, 4, 1)
for (date in startDate..endDate step 2) {
    println(date)
}

Using with in operator:

import me.moallemi.tools.daterange.localdate.rangeTo

val startDate = LocalDate.of(2020, 1, 1)
val endDate = LocalDate.of(2020, 1, 5)

val result: Boolean = LocalDate.of(2020, 1, 2) in (startDate..endDate)

with java.util.Date

Using rangeTo operator:

import me.moallemi.tools.daterange.date.rangeTo

val calendar = Calendar.getInstance(Locale.getDefault())
calendar.set(2020, 0, 1)
val startDate = calendar.time
calendar.set(2020, 0, 5)
val endDate = calendar.time
for (date in startDate..endDate) {
    println(date)
}

Usage with step function:

import me.moallemi.tools.daterange.date.rangeTo

for (date in startDate..endDate step 2) {
    println(date)
}

License

Copyright 2020 Reza Moallemi.

Licensed to the Apache Software Foundation (ASF) under one or more contributor
license agreements. See the NOTICE file distributed with this work for
additional information regarding copyright ownership. The ASF licenses this
file to you under the Apache License, Version 2.0 (the "License"); you may not
use this file except in compliance with the License. You may obtain a copy of
the License at

   http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
License for the specific language governing permissions and limitations under
the License.

kotlin-date-range's Issues

Lower API level to 21

It's possible to use java.time classes before API 26 when desugaring java.time.

More information:
https://code.luasoftware.com/tutorials/android/android-use-java-time-with-java8-liberary-desugaring/

This would enable the library to be used by lower API devices, without sacrificing any feature

[Discussion] Add syntax sugar for LocalDateTime.rangeTo(LocalDate)

val myTime: LocalDateTime

val range = myTime..LocalDate.now()

This currently isn't possible, and we need to adapt myTime to get it's LocalDate part:

val range = myTime.toLocalDate()..LocalDate.now()

I'd love to not have to do this, thus adding a syntax sugar can help in that way.

However, I can see how this is very error-prone, so I"d like to open this one for discussion.