Fixed ranges.

Author: ianbrandt

subprojects/user-defined-integrals-in-kotlin/src/main/kotlin/org/sdkotlin/integral/IntegralRange.kt

@@ -15,7 +15,7 @@ class IntegralRange<I : Integral<I>>(
 	override val endInclusive: I = last
 
 	override val endExclusive: I by lazy {
-		check(endInclusive == start.maxValue) {
+		check(endInclusive != endInclusive.maxValue) {
 			"Cannot return the exclusive upper bound of a range that includes MAX_VALUE."
 		}
 		endInclusive + endInclusive.one

subprojects/user-defined-integrals-in-kotlin/src/main/kotlin/org/sdkotlin/integral/UOctal.kt

@@ -40,7 +40,7 @@ value class UOctal internal constructor(
 	override fun compareTo(other: UOctal): Int =
 		data.compareTo(other.data)
 
-	operator fun rangeTo(other: UOctal): OpenEndRange<UOctal> =
+	operator fun rangeTo(other: UOctal): ClosedRange<UOctal> =
 		IntegralRange(this, other)
 
 	operator fun rangeUntil(other: UOctal): OpenEndRange<UOctal> =

subprojects/user-defined-integrals-in-kotlin/src/test/kotlin/org/sdkotlin/integral/SignedIntegral.kt

@@ -12,6 +12,8 @@ value class SignedIntegral(private val i: Int) : Integral<SignedIntegral> {
 		val ZERO: SignedIntegral = SignedIntegral(0)
 
 		val ONE: SignedIntegral = SignedIntegral(1)
+
+		val NEGATIVE_ONE: SignedIntegral = SignedIntegral(-1)
 	}
 
 	override val minValue: SignedIntegral
@@ -46,4 +48,9 @@ value class SignedIntegral(private val i: Int) : Integral<SignedIntegral> {
 
 	operator fun rangeUntil(other: SignedIntegral): OpenEndRange<SignedIntegral> =
 		IntegralRange(this, other - ONE)
+
+	override fun toString(): String = i.toString()
 }
+
+infix fun SignedIntegral.downTo(to: SignedIntegral): IntegralProgression<SignedIntegral> =
+	IntegralProgression.fromClosedRange(this, to, SignedIntegral.NEGATIVE_ONE)