Numbers

The constraints of numbers. The range and sign rules work on every number type, Int, Long, Short, Byte, Double, Float, BigInteger and BigDecimal, with an argument of the same type.

A null argument checks nothing. A rule that reads a value that may be missing, such as max(customer.limit), never fails because of it: required on that value reports it once.

PriceTag.kt

data class PriceTag(
    val price: BigDecimal?,
    val discountPercent: Int?,
    val packSize: Int?,
    val stock: Long?
) : Validatable {
    override fun validation() = validation {
        ::price required {
            positive()
            maxDecimalPlaces(2)
        }
        ::discountPercent required { between(min = 0, max = 90) }
        ::packSize required { multipleOf(6) }
        ::stock required { positiveOrZero() }
    }
}

Kotlin’s unsigned types, UInt, ULong, UShort and UByte, have the range constraints too, with arguments written with the u suffix. They cannot be negative, so they have no sign rules:

Packet.kt

data class Packet(
    val ttl: UByte?,
    val port: UShort?,
    val sequence: ULong?
) : Validatable {
    override fun validation() = validation {
        ::ttl required { between(min = 1u, max = 64u) }
        ::port required { min(1024u) }
        ::sequence required { min(1uL) }
    }
}

Constraint	Checks
`min`	Is at least `min`.
`max`	Is at most `max`.
`greaterThan`	Is greater than `other`.
`lessThan`	Is less than `other`.
`between`	Is between `min` and `max`, both included.
`positive`	Is greater than zero.
`negative`	Is less than zero.
`positiveOrZero`	Is zero or greater.
`negativeOrZero`	Is zero or less.
`integer`	Has no fractional part.
`multipleOf`	Is a multiple of `factor`.
`finite`	Is neither infinite nor `NaN`.
`minDigits`	Has at least `min` digits, not counting the sign.
`maxDigits`	Has at most `max` digits, not counting the sign.
`digitCount`	Has exactly `count` digits, not counting the sign.
`maxIntegerDigits`	Has at most `max` digits before the decimal point.
`maxDecimalPlaces`	Has at most `max` digits after the decimal point.
`decimalPlaces`	Has exactly `count` digits after the decimal point.
`minDecimalPlaces`	Has at least `min` digits after the decimal point.

Range

`min`

min(min) on every number type: Int, Long, Short, Byte, Double, Float, BigInteger, BigDecimal, and the unsigned UInt, ULong, UShort, UByte Checks that the number is at least min. min

`max`

max(max) on every number type: Int, Long, Short, Byte, Double, Float, BigInteger, BigDecimal, and the unsigned UInt, ULong, UShort, UByte Checks that the number is at most max. max

`greaterThan`

greaterThan(other) on every number type: Int, Long, Short, Byte, Double, Float, BigInteger, BigDecimal, and the unsigned UInt, ULong, UShort, UByte Checks that the number is greater than other. greaterThan

`lessThan`

lessThan(other) on every number type: Int, Long, Short, Byte, Double, Float, BigInteger, BigDecimal, and the unsigned UInt, ULong, UShort, UByte Checks that the number is less than other. lessThan

`between`

between(min, max) on every number type: Int, Long, Short, Byte, Double, Float, BigInteger, BigDecimal, and the unsigned UInt, ULong, UShort, UByte Checks that the number is between min and max, both included. between

Sign

`positive`

positive() on every number type: Int, Long, Short, Byte, Double, Float, BigInteger, BigDecimal Checks that the number is greater than zero. positive

`negative`

negative() on every number type: Int, Long, Short, Byte, Double, Float, BigInteger, BigDecimal Checks that the number is less than zero. negative

`positiveOrZero`

positiveOrZero() on every number type: Int, Long, Short, Byte, Double, Float, BigInteger, BigDecimal Checks that the number is zero or greater. positiveOrZero

`negativeOrZero`

negativeOrZero() on every number type: Int, Long, Short, Byte, Double, Float, BigInteger, BigDecimal Checks that the number is zero or less. negativeOrZero

Whole numbers and multiples

`integer`

integer() on Double, Float, BigDecimal Checks that the number has no fractional part. Infinity and NaN fail. Trailing zeros do not count, so 2.00 passes. integer

`multipleOf`

multipleOf(factor) on every number type: Int, Long, Short, Byte, BigInteger, BigDecimal, Double, Float Checks that the number is a multiple of factor. The remainder is computed in decimal, so 0.3 is a multiple of 0.1. Infinity and NaN fail. multipleOf

`finite`

finite() on Double, Float Checks that the number is neither infinite nor NaN. finite

Digits

`minDigits`

minDigits(min) on Int, Long, Short, Byte, BigInteger Checks that the number has at least min digits, not counting the sign. minDigits

`maxDigits`

maxDigits(max) on Int, Long, Short, Byte, BigInteger Checks that the number has at most max digits, not counting the sign. maxDigits

`digitCount`

digitCount(count) on Int, Long, Short, Byte, BigInteger Checks that the number has exactly count digits, not counting the sign. digitCount

`maxIntegerDigits`

maxIntegerDigits(max) on BigDecimal Checks that the number has at most max digits before the decimal point. maxIntegerDigits

Decimal places

`maxDecimalPlaces`

maxDecimalPlaces(max) on BigDecimal, Double, Float Checks that the number has at most max digits after the decimal point. Trailing zeros do not count, so 1.50 has one decimal place. On Double and Float, the number is read in decimal, the way it prints. Infinity and NaN fail. maxDecimalPlaces

`decimalPlaces`

decimalPlaces(count) on BigDecimal Checks that the number has exactly count digits after the decimal point. Trailing zeros count, so 1.50 has two decimal places, and a whole number has none. decimalPlaces

`minDecimalPlaces`

minDecimalPlaces(min) on BigDecimal Checks that the number has at least min digits after the decimal point. Trailing zeros count, so 1.50 has two decimal places. minDecimalPlaces

Double and Float are binary, so 0.1 + 0.2 is 0.30000000000000004. multipleOf and maxDecimalPlaces on them read the number in decimal, the way it prints, so 0.3 is a multiple of 0.1. For money, prefer BigDecimal.

Overview

Values

Time

Formats

Countries and phones

Messages

Range

`min`

`max`

`greaterThan`

`lessThan`

`between`

Sign

`positive`

`negative`

`positiveOrZero`

`negativeOrZero`

Whole numbers and multiples

`integer`

`multipleOf`

`finite`

Digits

`minDigits`

`maxDigits`

`digitCount`

`maxIntegerDigits`

Decimal places

`maxDecimalPlaces`

`decimalPlaces`

`minDecimalPlaces`

​Range

​min

​max

​greaterThan

​lessThan

​between

​Sign

​positive

​negative

​positiveOrZero

​negativeOrZero

​Whole numbers and multiples

​integer

​multipleOf

​finite

​Digits

​minDigits

​maxDigits

​digitCount

​maxIntegerDigits

​Decimal places

​maxDecimalPlaces

​decimalPlaces

​minDecimalPlaces

Range

`min`

`max`

`greaterThan`

`lessThan`

`between`

Sign

`positive`

`negative`

`positiveOrZero`

`negativeOrZero`

Whole numbers and multiples

`integer`

`multipleOf`

`finite`

Digits

`minDigits`

`maxDigits`

`digitCount`

`maxIntegerDigits`

Decimal places

`maxDecimalPlaces`

`decimalPlaces`

`minDecimalPlaces`