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author | Dmitry Nadezhin <Dmitry.Nadezhin@gmail.com> | 2012-04-02 10:29:25 +0400 |
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committer | Dmitry Nadezhin <Dmitry.Nadezhin@gmail.com> | 2012-04-02 10:29:25 +0400 |
commit | 883ca63361a039f27e412eb0cb1bee7e9742a0bb (patch) | |
tree | 94faf198670c55ee613a2e182ce740bee75ce837 | |
parent | f7535f72903f083b2444fb1d0b73363efa5482e9 (diff) | |
download | scala-883ca63361a039f27e412eb0cb1bee7e9742a0bb.tar.gz scala-883ca63361a039f27e412eb0cb1bee7e9742a0bb.tar.bz2 scala-883ca63361a039f27e412eb0cb1bee7e9742a0bb.zip |
SI-5627 BigInt.equals(Number) and BigDecimal.equals(Number) should implement equality in mathematical sense
-rw-r--r-- | src/library/scala/math/BigDecimal.scala | 15 | ||||
-rw-r--r-- | src/library/scala/math/BigInt.scala | 38 | ||||
-rw-r--r-- | test/files/run/is-valid-num.scala | 77 | ||||
-rw-r--r-- | test/files/run/numbereq.scala | 35 |
4 files changed, 162 insertions, 3 deletions
diff --git a/src/library/scala/math/BigDecimal.scala b/src/library/scala/math/BigDecimal.scala index c1f45eccfb..cb42b76b51 100644 --- a/src/library/scala/math/BigDecimal.scala +++ b/src/library/scala/math/BigDecimal.scala @@ -183,7 +183,8 @@ extends ScalaNumber with ScalaNumericConversions with Serializable { override def equals (that: Any): Boolean = that match { case that: BigDecimal => this equals that case that: BigInt => this.toBigIntExact exists (that equals _) - case _: Float | _: Double => unifiedPrimitiveEquals(that) + case that: Double => isValidDouble && toDouble == that + case that: Float => isValidFloat && toFloat == that case _ => isValidLong && unifiedPrimitiveEquals(that) } override def isValidByte = noArithmeticException(toByteExact) @@ -191,6 +192,18 @@ extends ScalaNumber with ScalaNumericConversions with Serializable { override def isValidChar = isValidInt && toIntExact >= Char.MinValue && toIntExact <= Char.MaxValue override def isValidInt = noArithmeticException(toIntExact) def isValidLong = noArithmeticException(toLongExact) + /** Returns `true` iff this can be represented exactly by [[scala.Float]]; otherwise returns `false`. + */ + def isValidFloat = { + val f = toFloat + !f.isInfinity && bigDecimal.compareTo(new java.math.BigDecimal(f)) == 0 + } + /** Returns `true` iff this can be represented exactly by [[scala.Double]]; otherwise returns `false`. + */ + def isValidDouble = { + val d = toDouble + !d.isInfinity && bigDecimal.compareTo(new java.math.BigDecimal(d)) == 0 + } private def noArithmeticException(body: => Unit): Boolean = { try { body ; true } diff --git a/src/library/scala/math/BigInt.scala b/src/library/scala/math/BigInt.scala index 8a53afaa62..dbec30b2fe 100644 --- a/src/library/scala/math/BigInt.scala +++ b/src/library/scala/math/BigInt.scala @@ -20,6 +20,7 @@ object BigInt { private val minCached = -1024 private val maxCached = 1024 private val cache = new Array[BigInt](maxCached - minCached + 1) + private val minusOne = BigInteger.valueOf(-1) @deprecated("Use Long.MinValue", "2.9.0") val MinLong = BigInt(Long.MinValue) @@ -122,6 +123,8 @@ class BigInt(val bigInteger: BigInteger) extends ScalaNumber with ScalaNumericCo override def equals(that: Any): Boolean = that match { case that: BigInt => this equals that case that: BigDecimal => that.toBigIntExact exists (this equals _) + case that: Double => isValidDouble && toDouble == that + case that: Float => isValidFloat && toFloat == that case x => isValidLong && unifiedPrimitiveEquals(x) } override def isValidByte = this >= Byte.MinValue && this <= Byte.MaxValue @@ -129,6 +132,41 @@ class BigInt(val bigInteger: BigInteger) extends ScalaNumber with ScalaNumericCo override def isValidChar = this >= Char.MinValue && this <= Char.MaxValue override def isValidInt = this >= Int.MinValue && this <= Int.MaxValue def isValidLong = this >= Long.MinValue && this <= Long.MaxValue + /** Returns `true` iff this can be represented exactly by [[scala.Float]]; otherwise returns `false`. + */ + def isValidFloat = { + val bitLen = bitLength + (bitLen <= 24 || + { + val lowest = lowestSetBit + bitLen <= java.lang.Float.MAX_EXPONENT + 1 && // exclude this < -2^128 && this >= 2^128 + lowest >= bitLen - 24 && + lowest < java.lang.Float.MAX_EXPONENT + 1 // exclude this == -2^128 + } + ) && !bitLengthOverflow + } + /** Returns `true` iff this can be represented exactly by [[scala.Double]]; otherwise returns `false`. + */ + def isValidDouble = { + val bitLen = bitLength + (bitLen <= 53 || + { + val lowest = lowestSetBit + bitLen <= java.lang.Double.MAX_EXPONENT + 1 && // exclude this < -2^1024 && this >= 2^1024 + lowest >= bitLen - 53 && + lowest < java.lang.Double.MAX_EXPONENT + 1 // exclude this == -2^1024 + } + ) && !bitLengthOverflow + } + /** Some implementations of java.math.BigInteger allow huge values with bit length greater than Int.MaxValue . + * The BigInteger.bitLength method returns truncated bit length in this case . + * This method tests if result of bitLength is valid. + * This method will become unnecessary if BigInt constructors reject huge BigIntegers. + */ + private def bitLengthOverflow = { + val shifted = bigInteger.shiftRight(Int.MaxValue) + (shifted.signum != 0) && !(shifted equals BigInt.minusOne) + } protected[math] def isWhole = true def underlying = bigInteger diff --git a/test/files/run/is-valid-num.scala b/test/files/run/is-valid-num.scala index f919a21dee..9c43e98911 100644 --- a/test/files/run/is-valid-num.scala +++ b/test/files/run/is-valid-num.scala @@ -1,11 +1,15 @@ object Test { def x = BigInt("10000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000") def y = BigDecimal("" + (Short.MaxValue + 1) + ".0") + def y1 = BigDecimal("0.1") + def y2 = BigDecimal("0.5") def l1 = Int.MaxValue.toLong + 1 def l2 = Int.MinValue.toLong - 1 def main(args: Array[String]): Unit = { + assert(!x.isValidDouble, x) + assert(!x.isValidFloat, x) assert(!x.isValidLong, x) assert(!x.isValidInt, x) assert(!x.isValidChar, x) @@ -13,8 +17,81 @@ object Test { assert(!y.isValidShort, y) assert(y.isValidChar, y) assert(y.isValidInt, y) + assert(y.isValidFloat, y) + assert(y.isValidDouble, y) + assert(!y1.isValidLong, y1) + assert(!y1.isValidFloat, y1) + assert(!y1.isValidDouble, y1) + assert(!y2.isValidLong, y2) + assert(y2.isValidFloat, y2) + assert(y2.isValidDouble, y2) + + testBigIntIsFloat() + testBigIntIsDouble() assert(!l1.isValidInt && (l1 - 1).isValidInt, l1) assert(!l2.isValidInt && (l2 + 1).isValidInt, l2) } + + def biExp2(e: Int) = BigInt(1) << e + + def testBigIntIsFloat() { + val prec = 24 + def checkFloatT(x: BigInt) = { + assert(x.isValidFloat, x) + assert((-x).isValidFloat, -x) + } + def checkFloatF(x: BigInt) = { + assert(!x.isValidFloat, x) + assert(!(-x).isValidFloat, -x) + } + checkFloatT(biExp2(prec) - 1) + checkFloatT(biExp2(prec)) + checkFloatF(biExp2(prec) + 1) + checkFloatT(biExp2(prec) + 2) + checkFloatT(biExp2(prec) - 2) + checkFloatF(biExp2(prec + 1) - 1) + checkFloatT(biExp2(prec + 1)) + checkFloatF(biExp2(prec + 1) + 1) + checkFloatF(biExp2(prec + 1) + 2) + checkFloatF(biExp2(prec + 1) + 3) + checkFloatT(biExp2(prec + 1) + 4) + checkFloatT(biExp2(64)) + checkFloatF(biExp2(64) + biExp2(64 - prec)) + checkFloatT(biExp2(64) + biExp2(64 - prec + 1)) + checkFloatT(biExp2(127)) + checkFloatT(biExp2(128) - biExp2(128 - prec)) + checkFloatF(biExp2(128) - biExp2(128 - prec - 1)) + checkFloatF(biExp2(128)) + } + + def testBigIntIsDouble() { + val prec = 53 + def checkDoubleT(x: BigInt) = { + assert(x.isValidDouble, x) + assert((-x).isValidDouble, -x) + } + def checkDoubleF(x: BigInt) = { + assert(!x.isValidDouble, x) + assert(!(-x).isValidDouble, -x) + } + checkDoubleT(biExp2(prec) - 1) + checkDoubleT(biExp2(prec)) + checkDoubleF(biExp2(prec) + 1) + checkDoubleT(biExp2(prec) + 2) + checkDoubleT(biExp2(prec + 1) - 2) + checkDoubleF(biExp2(prec + 1) - 1) + checkDoubleT(biExp2(prec + 1)) + checkDoubleF(biExp2(prec + 1) + 1) + checkDoubleF(biExp2(prec + 1) + 2) + checkDoubleF(biExp2(prec + 1) + 3) + checkDoubleT(biExp2(prec + 1) + 4) + checkDoubleT(biExp2(64)) + checkDoubleF(biExp2(64) + biExp2(64 - prec)) + checkDoubleT(biExp2(64) + biExp2(64 - prec + 1)) + checkDoubleT(biExp2(1023)) + checkDoubleT(biExp2(1024) - biExp2(1024 - prec)) + checkDoubleF(biExp2(1024) - biExp2(1024 - prec - 1)) + checkDoubleF(biExp2(1024)) + } } diff --git a/test/files/run/numbereq.scala b/test/files/run/numbereq.scala index 77a217df36..a1f11da205 100644 --- a/test/files/run/numbereq.scala +++ b/test/files/run/numbereq.scala @@ -16,7 +16,20 @@ object Test { base ::: extras } - + + def mkNumbers(x: BigInt): List[AnyRef] = { + List( + List(BigDecimal(x, java.math.MathContext.UNLIMITED)), + List(x), + if (x.isValidDouble) List(new java.lang.Double(x.toDouble)) else Nil, + if (x.isValidFloat) List(new java.lang.Float(x.toFloat)) else Nil, + if (x.isValidLong) List(new java.lang.Long(x.toLong)) else Nil, + if (x.isValidInt) List(new java.lang.Integer(x.toInt)) else Nil, + if (x.isValidShort) List(new java.lang.Short(x.toShort)) else Nil, + if (x.isValidByte) List(new java.lang.Byte(x.toByte)) else Nil, + if (x.isValidChar) List(new java.lang.Character(x.toChar)) else Nil + ).flatten + } def main(args: Array[String]): Unit = { val ints = (0 to 15).toList map (Short.MinValue >> _) @@ -37,5 +50,23 @@ object Test { assert(x == y, "%s/%s != %s/%s".format(x, x.getClass, y, y.getClass)) assert(x.## == y.##, "%s != %s".format(x.getClass, y.getClass)) } + + val bigInts = (0 to 1024).toList map (BigInt(-1) << _) + val bigInts2 = bigInts map (x => -x) + val bigInts3 = bigInts map (_ + 1) + val bigInts4 = bigInts2 map (_ - 1) + + val setneg1b = bigInts map mkNumbers + val setneg2b = bigInts3 map mkNumbers + val setpos1b = bigInts2 map mkNumbers + val setpos2b = bigInts4 map mkNumbers + + val sets2 = setneg1 ++ setneg1b ++ setneg2 ++ setneg2b ++ List(zero) ++ setpos1 ++ setpos1b ++ setpos2 ++ setpos2b + + for (set <- sets2 ; x <- set ; y <- set) { +// println("'%s' == '%s' (%s == %s) (%s == %s)".format(x, y, x.hashCode, y.hashCode, x.##, y.##)) + assert(x == y, "%s/%s != %s/%s".format(x, x.getClass, y, y.getClass)) +// assert(x.## == y.##, "%s != %s".format(x.getClass, y.getClass)) Disable until Double.## is fixed (SI-5640) + } } -}
\ No newline at end of file +} |