kmath-core/src/commonMain/kotlin/scientifik/kmath/operations/KBigInteger.kt

@@ -26,45 +26,256 @@ object KBigIntegerRing: Ring<KBigInteger> {
 
     override fun multiply(a: KBigInteger, b: KBigInteger): KBigInteger = a.times(b)
 
-    operator fun String.unaryPlus(): KBigInteger = KBigInteger(this)!!
+    operator fun String.unaryPlus(): KBigInteger = this.toKBigInteger()!!
 
-    operator fun String.unaryMinus(): KBigInteger = -KBigInteger(this)!!
+    operator fun String.unaryMinus(): KBigInteger = -this.toKBigInteger()!!
 }
 
-
 @kotlin.ExperimentalUnsignedTypes
-class KBigInteger(sign: Int = 0, magnitude: Magnitude = Magnitude(0)):
-        RingElement<KBigInteger, KBigInteger, KBigIntegerRing>, Comparable<KBigInteger> {
+class KBigInteger internal constructor(
+        private val sign: Byte = 0,
+        private val magnitude: Magnitude = Magnitude(0)
+): Comparable<KBigInteger> {
 
-    constructor(x: Int) : this(x.sign, uintArrayOf(kotlin.math.abs(x).toUInt()))
-    constructor(x: Long) : this(x.sign, uintArrayOf(
+    constructor(x: Int) : this(x.sign.toByte(), uintArrayOf(kotlin.math.abs(x).toUInt()))
+
+    constructor(x: Long) : this(x.sign.toByte(), stripLeadingZeros(uintArrayOf(
             (kotlin.math.abs(x).toULong() and BASE).toUInt(),
-            ((kotlin.math.abs(x).toULong() shr BASE_SIZE) and BASE).toUInt()))
+            ((kotlin.math.abs(x).toULong() shr BASE_SIZE) and BASE).toUInt())))
 
-    val magnitude = stripLeadingZeros(magnitude)
-    val sign = if (this.magnitude.isNotEmpty()) sign else 0
-    val sizeByte: Int = magnitude.size * BASE_SIZE / 4
+    override fun compareTo(other: KBigInteger): Int {
+        return when {
+            (this.sign == 0.toByte()) and (other.sign == 0.toByte()) -> 0
+            this.sign < other.sign -> -1
+            this.sign > other.sign -> 1
+            else -> this.sign * compareMagnitudes(this.magnitude, other.magnitude)
+        }
+    }
 
-    override val context: KBigIntegerRing get() = KBigIntegerRing
+    override fun equals(other: Any?): Boolean {
+        if (other is KBigInteger) {
+            return this.compareTo(other) == 0
+        }
+        else error("Can't compare KBigInteger to a different type")
+    }
 
-    override fun unwrap(): KBigInteger = this
-    override fun KBigInteger.wrap(): KBigInteger = this
+    override fun hashCode(): Int {
+        return magnitude.hashCode() + this.sign
+    }
+
+    fun abs(): KBigInteger = if (sign == 0.toByte()) this else KBigInteger(1, magnitude)
+
+    operator fun unaryMinus(): KBigInteger {
+        return if (this.sign == 0.toByte()) this else KBigInteger((-this.sign).toByte(), this.magnitude)
+    }
+
+    operator fun plus(b: KBigInteger): KBigInteger {
+        return when {
+            b.sign == 0.toByte() -> this
+            this.sign == 0.toByte() -> b
+            this == -b -> ZERO
+            this.sign == b.sign -> KBigInteger(this.sign, addMagnitudes(this.magnitude, b.magnitude))
+            else -> {
+                val comp: Int = compareMagnitudes(this.magnitude, b.magnitude)
+
+                if (comp == 1) {
+                    KBigInteger(this.sign, subtractMagnitudes(this.magnitude, b.magnitude))
+                } else {
+                    KBigInteger((-this.sign).toByte(), subtractMagnitudes(b.magnitude, this.magnitude))
+                }
+            }
+        }
+    }
+
+    operator fun minus(b: KBigInteger): KBigInteger {
+        return this + (-b)
+    }
+
+    operator fun times(b: KBigInteger): KBigInteger {
+        return when {
+            this.sign == 0.toByte() -> ZERO
+            b.sign == 0.toByte() -> ZERO
+//          TODO: Karatsuba
+            else -> KBigInteger((this.sign * b.sign).toByte(), multiplyMagnitudes(this.magnitude, b.magnitude))
+        }
+    }
+
+    operator fun times(other: UInt): KBigInteger {
+        return when {
+            this.sign == 0.toByte() -> ZERO
+            other == 0U -> ZERO
+            else -> KBigInteger(this.sign, multiplyMagnitudeByUInt(this.magnitude, other))
+        }
+    }
+
+    operator fun times(other: Int): KBigInteger {
+        return if (other > 0)
+            this * kotlin.math.abs(other).toUInt()
+        else
+            -this * kotlin.math.abs(other).toUInt()
+    }
+
+    operator fun div(other: UInt): KBigInteger {
+        return KBigInteger(this.sign, divideMagnitudeByUInt(this.magnitude, other))
+    }
+
+    operator fun div(other: Int): KBigInteger {
+        return KBigInteger((this.sign * other.sign).toByte(),
+                divideMagnitudeByUInt(this.magnitude, kotlin.math.abs(other).toUInt()))
+    }
+
+    private fun division(other: KBigInteger): Pair<KBigInteger, KBigInteger> {
+        // Long division algorithm:
+        //     https://en.wikipedia.org/wiki/Division_algorithm#Integer_division_(unsigned)_with_remainder
+        // TODO: Implement more effective algorithm
+        var q: KBigInteger = ZERO
+        var r: KBigInteger = ZERO
+
+        val bitSize = (BASE_SIZE * (this.magnitude.size - 1) + log2(this.magnitude.last().toFloat() + 1)).toInt()
+        for (i in bitSize downTo 0) {
+            r = r shl 1
+            r = r or ((abs(this) shr i) and ONE)
+            if (r >= abs(other)) {
+                r -= abs(other)
+                q += (ONE shl i)
+            }
+        }
+
+        return Pair(KBigInteger((this.sign * other.sign).toByte(), q.magnitude), r)
+    }
+
+    operator fun div(other: KBigInteger): KBigInteger {
+        return this.division(other).first
+    }
+
+    infix fun shl(i: Int): KBigInteger {
+        if (this == ZERO) return ZERO
+        if (i == 0) return this
+
+        val fullShifts = i / BASE_SIZE + 1
+        val relShift = i % BASE_SIZE
+        val shiftLeft = {x: UInt -> if (relShift >= 32) 0U else x shl relShift}
+        val shiftRight = {x: UInt -> if (BASE_SIZE - relShift >= 32) 0U else x shr (BASE_SIZE - relShift)}
+
+        val newMagnitude: Magnitude = Magnitude(this.magnitude.size + fullShifts)
+
+        for (j in this.magnitude.indices) {
+            newMagnitude[j + fullShifts - 1] = shiftLeft(this.magnitude[j])
+            if (j != 0) {
+                newMagnitude[j + fullShifts - 1] = newMagnitude[j + fullShifts - 1] or shiftRight(this.magnitude[j - 1])
+            }
+        }
+
+        newMagnitude[this.magnitude.size + fullShifts - 1] = shiftRight(this.magnitude.last())
+
+        return KBigInteger(this.sign, stripLeadingZeros(newMagnitude))
+    }
+
+    infix fun shr(i: Int): KBigInteger {
+        if (this == ZERO) return ZERO
+        if (i == 0) return this
+
+        val fullShifts = i / BASE_SIZE
+        val relShift = i % BASE_SIZE
+        val shiftRight = {x: UInt -> if (relShift >= 32) 0U else x shr relShift}
+        val shiftLeft = {x: UInt -> if (BASE_SIZE - relShift >= 32) 0U else x shl (BASE_SIZE - relShift)}
+        if (this.magnitude.size - fullShifts <= 0) {
+            return ZERO
+        }
+        val newMagnitude: Magnitude = Magnitude(this.magnitude.size - fullShifts)
+
+        for (j in fullShifts until this.magnitude.size) {
+            newMagnitude[j - fullShifts] = shiftRight(this.magnitude[j])
+            if (j != this.magnitude.size - 1) {
+                newMagnitude[j - fullShifts] = newMagnitude[j - fullShifts] or shiftLeft(this.magnitude[j + 1])
+            }
+        }
+
+        return KBigInteger(this.sign, stripLeadingZeros(newMagnitude))
+    }
+
+    infix fun or(other: KBigInteger): KBigInteger {
+        if (this == ZERO) return other;
+        if (other == ZERO) return this;
+        val resSize = max(this.magnitude.size, other.magnitude.size)
+        val newMagnitude: Magnitude = Magnitude(resSize)
+        for (i in 0 until resSize) {
+            if (i < this.magnitude.size) {
+                newMagnitude[i] = newMagnitude[i] or this.magnitude[i]
+            }
+            if (i < other.magnitude.size) {
+                newMagnitude[i] = newMagnitude[i] or other.magnitude[i]
+            }
+        }
+        return KBigInteger(1, stripLeadingZeros(newMagnitude))
+    }
+
+    infix fun and(other: KBigInteger): KBigInteger {
+        if ((this == ZERO) or (other == ZERO)) return ZERO;
+        val resSize = min(this.magnitude.size, other.magnitude.size)
+        val newMagnitude: Magnitude = Magnitude(resSize)
+        for (i in 0 until resSize) {
+            newMagnitude[i] = this.magnitude[i] and other.magnitude[i]
+        }
+        return KBigInteger(1, stripLeadingZeros(newMagnitude))
+    }
+
+    operator fun rem(other: Int): Int {
+        val res = this - (this / other) * other
+        return if (res == ZERO) 0 else res.sign * res.magnitude[0].toInt()
+    }
+
+    operator fun rem(other: KBigInteger): KBigInteger {
+        return this - (this / other) * other
+    }
+
+    fun modPow(exponent: KBigInteger, m: KBigInteger): KBigInteger {
+        return when {
+            exponent == ZERO -> ONE
+            exponent % 2 == 1 -> (this * modPow(exponent - ONE, m)) % m
+            else -> {
+                val sqRoot = modPow(exponent / 2, m)
+                (sqRoot * sqRoot) % m
+            }
+        }
+    }
+
+    override fun toString(): String {
+        if (this.sign == 0.toByte()) {
+            return "0x0"
+        }
+        var res: String = if (this.sign == (-1).toByte()) "-0x" else "0x"
+        var numberStarted = false
+
+        for (i in this.magnitude.size - 1 downTo 0) {
+            for (j in BASE_SIZE / 4 - 1 downTo 0) {
+                val curByte = (this.magnitude[i] shr 4 * j) and 0xfU
+                if (numberStarted or (curByte != 0U)) {
+                    numberStarted = true
+                    res += hexMapping[curByte]
+                }
+            }
+        }
+
+        return res
+    }
 
     companion object {
-        val BASE = 0xffffffffUL
+        const val BASE = 0xffffffffUL
         const val BASE_SIZE: Int = 32
         val ZERO: KBigInteger = KBigInteger()
         val ONE: KBigInteger = KBigInteger(1)
 
         private val hexMapping: HashMap<UInt, String> =
                 hashMapOf(
-                        0U to "0", 1U to "1", 2U to "2", 3U to "3", 4U to "4", 5U to "5", 6U to "6", 7U to "7", 8U to "8",
-                        9U to "9", 10U to "a", 11U to "b", 12U to "c", 13U to "d", 14U to "e", 15U to "f"
+                        0U to "0",  1U to "1",  2U to "2",  3U to "3",
+                        4U to "4",  5U to "5",  6U to "6",  7U to "7",
+                        8U to "8",  9U to "9",  10U to "a", 11U to "b",
+                        12U to "c", 13U to "d", 14U to "e", 15U to "f"
                 )
 
-        private fun stripLeadingZeros(mag: Magnitude): Magnitude {
-            // TODO: optimize performance
-            if (mag.isEmpty()) {
+        internal fun stripLeadingZeros(mag: Magnitude): Magnitude {
+            if (mag.isEmpty() || mag.last() != 0U) {
                 return mag
             }
             var resSize: Int = mag.size - 1
@@ -108,7 +319,7 @@ class KBigInteger(sign: Int = 0, magnitude: Magnitude = Magnitude(0)):
                 carry = (res shr BASE_SIZE)
             }
             result[resultLength - 1] = carry.toUInt()
-            return result
+            return stripLeadingZeros(result)
         }
 
         private fun subtractMagnitudes(mag1: Magnitude, mag2: Magnitude): Magnitude {
@@ -127,7 +338,7 @@ class KBigInteger(sign: Int = 0, magnitude: Magnitude = Magnitude(0)):
                 result[i] = res.toUInt()
             }
 
-            return result
+            return stripLeadingZeros(result)
         }
 
         private fun multiplyMagnitudeByUInt(mag: Magnitude, x: UInt): Magnitude {
@@ -142,7 +353,7 @@ class KBigInteger(sign: Int = 0, magnitude: Magnitude = Magnitude(0)):
             }
             result[resultLength - 1] = (carry and BASE).toUInt()
 
-            return result
+            return stripLeadingZeros(result)
         }
 
         private fun multiplyMagnitudes(mag1: Magnitude, mag2: Magnitude): Magnitude {
@@ -159,7 +370,7 @@ class KBigInteger(sign: Int = 0, magnitude: Magnitude = Magnitude(0)):
                 result[i + mag2.size] = (carry and BASE).toUInt()
             }
 
-            return result
+            return stripLeadingZeros(result)
         }
 
         private fun divideMagnitudeByUInt(mag: Magnitude, x: UInt): Magnitude {
@@ -172,230 +383,15 @@ class KBigInteger(sign: Int = 0, magnitude: Magnitude = Magnitude(0)):
                 result[i] = (cur / x).toUInt()
                 carry = cur % x
             }
-            return result
+            return stripLeadingZeros(result)
         }
 
     }
 
-    override fun compareTo(other: KBigInteger): Int {
-        return when {
-            (this.sign == 0) and (other.sign == 0) -> 0
-            this.sign < other.sign -> -1
-            this.sign > other.sign -> 1
-            else -> this.sign * compareMagnitudes(this.magnitude, other.magnitude)
-        }
-    }
-
-    override fun equals(other: Any?): Boolean {
-        if (other is KBigInteger) {
-            return this.compareTo(other) == 0
-        }
-        else error("Can't compare KBigInteger to a different type")
-    }
-
-    override fun hashCode(): Int {
-        return magnitude.hashCode() + this.sign
-    }
-
-    operator fun unaryMinus(): KBigInteger {
-        return if (this.sign == 0) this else KBigInteger(-this.sign, this.magnitude)
-    }
-
-    override operator fun plus(b: KBigInteger): KBigInteger {
-        return when {
-            b.sign == 0 -> this
-            this.sign == 0 -> b
-            this == -b -> ZERO
-            this.sign == b.sign -> KBigInteger(this.sign, addMagnitudes(this.magnitude, b.magnitude))
-            else -> {
-                val comp: Int = compareMagnitudes(this.magnitude, b.magnitude)
-
-                if (comp == 1) {
-                    KBigInteger(this.sign, subtractMagnitudes(this.magnitude, b.magnitude))
-                } else {
-                    KBigInteger(-this.sign, subtractMagnitudes(b.magnitude, this.magnitude))
-                }
-            }
-        }
-    }
-
-    override operator fun minus(b: KBigInteger): KBigInteger {
-        return this + (-b)
-    }
-
-    override operator fun times(b: KBigInteger): KBigInteger {
-        return when {
-            this.sign == 0 -> ZERO
-            b.sign == 0 -> ZERO
-//          TODO: Karatsuba
-            else -> KBigInteger(this.sign * b.sign, multiplyMagnitudes(this.magnitude, b.magnitude))
-        }
-    }
-
-    operator fun times(other: UInt): KBigInteger {
-        return when {
-            this.sign == 0 -> ZERO
-            other == 0U -> ZERO
-            else -> KBigInteger(this.sign, multiplyMagnitudeByUInt(this.magnitude, other))
-        }
-    }
-
-    operator fun times(other: Int): KBigInteger {
-        return if (other > 0)
-            this * kotlin.math.abs(other).toUInt()
-        else
-            -this * kotlin.math.abs(other).toUInt()
-    }
-
-    operator fun div(other: UInt): KBigInteger {
-        return KBigInteger(this.sign, divideMagnitudeByUInt(this.magnitude, other))
-    }
-
-    operator fun div(other: Int): KBigInteger {
-        return KBigInteger(this.sign * other.sign, divideMagnitudeByUInt(this.magnitude, kotlin.math.abs(other).toUInt()))
-    }
-
-    private fun division(other: KBigInteger): Pair<KBigInteger, KBigInteger> {
-        // Long division algorithm:
-        //     https://en.wikipedia.org/wiki/Division_algorithm#Integer_division_(unsigned)_with_remainder
-        // TODO: Implement more effective algorithm
-        var q: KBigInteger = ZERO
-        var r: KBigInteger = ZERO
-
-        val bitSize = (BASE_SIZE * (this.magnitude.size - 1) + log2(this.magnitude.last().toFloat() + 1)).toInt()
-        for (i in bitSize downTo 0) {
-            r = r shl 1
-            r = r or ((abs(this) shr i) and ONE)
-            if (r >= abs(other)) {
-                r -= abs(other)
-                q += (ONE shl i)
-            }
-        }
-
-        return Pair(KBigInteger(this.sign * other.sign, q.magnitude), r)
-    }
-
-    operator fun div(other: KBigInteger): KBigInteger {
-        return this.division(other).first
-    }
-
-    infix fun shl(i: Int): KBigInteger {
-        if (this == ZERO) return ZERO
-        if (i == 0) return this
-
-        val fullShifts = i / BASE_SIZE + 1
-        val relShift = i % BASE_SIZE
-        val shiftLeft = {x: UInt -> if (relShift >= 32) 0U else x shl relShift}
-        val shiftRight = {x: UInt -> if (BASE_SIZE - relShift >= 32) 0U else x shr (BASE_SIZE - relShift)}
-
-        val newMagnitude: Magnitude = Magnitude(this.magnitude.size + fullShifts)
-
-        for (j in this.magnitude.indices) {
-            newMagnitude[j + fullShifts - 1] = shiftLeft(this.magnitude[j])
-            if (j != 0) {
-                newMagnitude[j + fullShifts - 1] = newMagnitude[j + fullShifts - 1] or shiftRight(this.magnitude[j - 1])
-            }
-        }
-
-        newMagnitude[this.magnitude.size + fullShifts - 1] = shiftRight(this.magnitude.last())
-
-        return KBigInteger(this.sign, newMagnitude)
-    }
-
-    infix fun shr(i: Int): KBigInteger {
-        if (this == ZERO) return ZERO
-        if (i == 0) return this
-
-        val fullShifts = i / BASE_SIZE
-        val relShift = i % BASE_SIZE
-        val shiftRight = {x: UInt -> if (relShift >= 32) 0U else x shr relShift}
-        val shiftLeft = {x: UInt -> if (BASE_SIZE - relShift >= 32) 0U else x shl (BASE_SIZE - relShift)}
-        if (this.magnitude.size - fullShifts <= 0) {
-            return ZERO
-        }
-        val newMagnitude: Magnitude = Magnitude(this.magnitude.size - fullShifts)
-
-        for (j in fullShifts until this.magnitude.size) {
-            newMagnitude[j - fullShifts] = shiftRight(this.magnitude[j])
-            if (j != this.magnitude.size - 1) {
-                newMagnitude[j - fullShifts] = newMagnitude[j - fullShifts] or shiftLeft(this.magnitude[j + 1])
-            }
-        }
-
-        return KBigInteger(this.sign, newMagnitude)
-    }
-
-    infix fun or(other: KBigInteger): KBigInteger {
-        if (this == ZERO) return other;
-        if (other == ZERO) return this;
-        val resSize = max(this.magnitude.size, other.magnitude.size)
-        val newMagnitude: Magnitude = Magnitude(resSize)
-        for (i in 0 until resSize) {
-            if (i < this.magnitude.size) {
-                newMagnitude[i] = newMagnitude[i] or this.magnitude[i]
-            }
-            if (i < other.magnitude.size) {
-                newMagnitude[i] = newMagnitude[i] or other.magnitude[i]
-            }
-        }
-        return KBigInteger(1, newMagnitude)
-    }
-
-    infix fun and(other: KBigInteger): KBigInteger {
-        if ((this == ZERO) or (other == ZERO)) return ZERO;
-        val resSize = min(this.magnitude.size, other.magnitude.size)
-        val newMagnitude: Magnitude = Magnitude(resSize)
-        for (i in 0 until resSize) {
-            newMagnitude[i] = this.magnitude[i] and other.magnitude[i]
-        }
-        return KBigInteger(1, newMagnitude)
-    }
-
-    operator fun rem(other: Int): Int {
-        val res = this - (this / other) * other
-        return if (res == ZERO) 0 else res.sign * res.magnitude[0].toInt()
-    }
-
-    operator fun rem(other: KBigInteger): KBigInteger {
-        return this - (this / other) * other
-    }
-
-    fun modPow(exponent: KBigInteger, m: KBigInteger): KBigInteger {
-        return when {
-            exponent == ZERO -> ONE
-            exponent % 2 == 1 -> (this * modPow(exponent - ONE, m)) % m
-            else -> {
-                val sqRoot = modPow(exponent / 2, m)
-                (sqRoot * sqRoot) % m
-            }
-        }
-    }
-
-    override fun toString(): String {
-        if (this.sign == 0) {
-            return "0x0"
-        }
-        var res: String = if (this.sign == -1) "-0x" else "0x"
-        var numberStarted = false
-
-        for (i in this.magnitude.size - 1 downTo 0) {
-            for (j in BASE_SIZE / 4 - 1 downTo 0) {
-                val curByte = (this.magnitude[i] shr 4 * j) and 0xfU
-                if (numberStarted or (curByte != 0U)) {
-                    numberStarted = true
-                    res += hexMapping[curByte]
-                }
-            }
-        }
-
-        return res
-    }
 }
 
 @kotlin.ExperimentalUnsignedTypes
-fun abs(x: KBigInteger): KBigInteger {
-    return if (x.sign == 0) x else KBigInteger(1, x.magnitude)
-}
+fun abs(x: KBigInteger): KBigInteger = x.abs()
 
 @kotlin.ExperimentalUnsignedTypes
 // Can't put it as constructor in class due to platform declaration clash with KBigInteger(Int)
@@ -405,26 +401,35 @@ fun KBigInteger(x: UInt): KBigInteger
 @kotlin.ExperimentalUnsignedTypes
 // Can't put it as constructor in class due to platform declaration clash with KBigInteger(Long)
 fun KBigInteger(x: ULong): KBigInteger
-        = KBigInteger(1, uintArrayOf((x and KBigInteger.BASE).toUInt(), ((x shr KBigInteger.BASE_SIZE) and KBigInteger.BASE).toUInt()))
+        = KBigInteger(1,
+            KBigInteger.stripLeadingZeros(uintArrayOf(
+                    (x and KBigInteger.BASE).toUInt(),
+                    ((x shr KBigInteger.BASE_SIZE) and KBigInteger.BASE).toUInt())
+            )
+        )
 
-val hexChToInt = hashMapOf('0' to 0, '1' to 1, '2' to 2, '3' to 3, '4' to 4, '5' to 5, '6' to 6, '7' to 7,
-        '8' to 8, '9' to 9, 'A' to 10, 'B' to 11, 'C' to 12, 'D' to 13, 'E' to 14, 'F' to 15)
+val hexChToInt = hashMapOf(
+        '0' to 0,  '1' to 1,  '2' to 2,  '3' to 3,
+        '4' to 4,  '5' to 5,  '6' to 6,  '7' to 7,
+        '8' to 8,  '9' to 9,  'A' to 10, 'B' to 11,
+        'C' to 12, 'D' to 13, 'E' to 14, 'F' to 15
+)
 
 // Returns None if a valid number can not be read from a string
-fun KBigInteger(s: String): KBigInteger? {
+fun String.toKBigInteger(): KBigInteger? {
     val sign: Int
     val sPositive: String
     when {
-        s[0] == '+' -> {
+        this[0] == '+' -> {
             sign = +1
-            sPositive = s.substring(1)
+            sPositive = this.substring(1)
         }
-        s[0] == '-' -> {
+        this[0] == '-' -> {
             sign = -1
-            sPositive = s.substring(1)
+            sPositive = this.substring(1)
         }
         else -> {
-            sPositive = s
+            sPositive = this
             sign = +1
         }
     }

kmath-core/src/commonTest/kotlin/scientifik/kmath/operations/KBigIntegerTest.kt

@@ -485,13 +485,13 @@ class KBigIntegerConversionsTest {
 
     @Test
     fun testFromString_0x17ead2ffffd11223344() {
-        val x = KBigInteger("0x17ead2ffffd11223344")!!
+        val x = "0x17ead2ffffd11223344".toKBigInteger()
         assertEquals( "0x17ead2ffffd11223344", x.toString())
     }
 
     @Test
     fun testFromString_7059135710711894913860() {
-        val x = KBigInteger("-7059135710711894913860")
+        val x = "-7059135710711894913860".toKBigInteger()
         assertEquals("-0x17ead2ffffd11223344", x.toString())
     }
 }
@@ -509,7 +509,7 @@ class KBigIntegerRingTest {
     fun testKBigIntegerRingSum_100_000_000__100_000_000() {
         KBigIntegerRing {
             val sum = +"100_000_000" + +"100_000_000"
-            assertEquals(sum, KBigInteger("200_000_000"))
+            assertEquals(sum, "200_000_000".toKBigInteger())
         }
     }
 
@@ -517,7 +517,7 @@ class KBigIntegerRingTest {
     fun test_mul_3__4() {
         KBigIntegerRing {
             val prod = +"0x3000_0000_0000" * +"0x4000_0000_0000_0000_0000"
-            assertEquals(prod, KBigInteger("0xc00_0000_0000_0000_0000_0000_0000_0000"))
+            assertEquals(prod, "0xc00_0000_0000_0000_0000_0000_0000_0000".toKBigInteger())
         }
     }