Merge pull request #3071 from xwu/decimal-floatingpoint

Restore previous value of `Decimal.leastFiniteMagnitude` for compatibility and deprecate

Author: xwu

Darwin/Foundation-swiftoverlay-Tests/TestDecimal.swift

@@ -123,8 +123,6 @@ class TestDecimal : XCTestCase {
         XCTAssertEqual(leastNormal, Decimal.leastNormalMagnitude)
         let leastNonzero = Decimal(_exponent: -128, _length: 1, _isNegative: 0, _isCompact: 1, _reserved: 0, _mantissa: (1, 0, 0, 0, 0, 0, 0, 0))
         XCTAssertEqual(leastNonzero, Decimal.leastNonzeroMagnitude)
-        let leastFinite = 0 as Decimal
-        XCTAssertEqual(leastFinite, Decimal.leastFiniteMagnitude)
         let pi = Decimal(_exponent: -38, _length: 8, _isNegative: 0, _isCompact: 1, _reserved: 0, _mantissa: (0x6623, 0x7d57, 0x16e7, 0xad0d, 0xaf52, 0x4641, 0xdfa7, 0xec58))
         XCTAssertEqual(pi, Decimal.pi)
         XCTAssertEqual(10, Decimal.radix)

Darwin/Foundation-swiftoverlay/Decimal.swift

@@ -350,7 +350,8 @@ extension Decimal {
 
     public static let leastNonzeroMagnitude = leastNormalMagnitude
 
-    public static let leastFiniteMagnitude = zero
+    @available(*, deprecated, message: "Use '-Decimal.greatestFiniteMagnitude' for least finite value or '0' for least finite magnitude")
+    public static let leastFiniteMagnitude = -greatestFiniteMagnitude
 
     public static let pi = Decimal(
         _exponent: -38,

Sources/Foundation/Decimal.swift

@@ -518,7 +518,8 @@ extension Decimal {
 
     public static let leastNonzeroMagnitude = leastNormalMagnitude
 
-    public static let leastFiniteMagnitude = zero
+    @available(*, deprecated, message: "Use '-Decimal.greatestFiniteMagnitude' for least finite value or '0' for least finite magnitude")
+    public static let leastFiniteMagnitude = -greatestFiniteMagnitude
 
     public static let pi = Decimal(
         _exponent: -38,

Tests/Foundation/Tests/TestDecimal.swift

@@ -147,8 +147,6 @@ class TestDecimal: XCTestCase {
         XCTAssertEqual(leastNormal, Decimal.leastNormalMagnitude)
         let leastNonzero = Decimal(_exponent: -128, _length: 1, _isNegative: 0, _isCompact: 1, _reserved: 0, _mantissa: (1, 0, 0, 0, 0, 0, 0, 0))
         XCTAssertEqual(leastNonzero, Decimal.leastNonzeroMagnitude)
-        let leastFinite = 0 as Decimal
-        XCTAssertEqual(leastFinite, Decimal.leastFiniteMagnitude)
         let pi = Decimal(_exponent: -38, _length: 8, _isNegative: 0, _isCompact: 1, _reserved: 0, _mantissa: (0x6623, 0x7d57, 0x16e7, 0xad0d, 0xaf52, 0x4641, 0xdfa7, 0xec58))
         XCTAssertEqual(pi, Decimal.pi)
         XCTAssertEqual(10, Decimal.radix)
@@ -185,7 +183,6 @@ class TestDecimal: XCTestCase {
         XCTAssertEqual("3402823669209384634633746074317682114550000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000", Decimal.greatestFiniteMagnitude.description)
         XCTAssertEqual("0.00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000001", Decimal.leastNormalMagnitude.description)
         XCTAssertEqual("0.00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000001", Decimal.leastNonzeroMagnitude.description)
-        XCTAssertEqual("0", Decimal.leastFiniteMagnitude.description)
 
         let fr = Locale(identifier: "fr_FR")
         let greatestFiniteMagnitude = "3402823669209384634633746074317682114550000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000"
@@ -387,7 +384,7 @@ class TestDecimal: XCTestCase {
         XCTAssertEqual((1 as Decimal).magnitude, abs(-1 as Decimal))
         XCTAssertEqual((-1 as Decimal).magnitude, abs(-1 as Decimal))
         XCTAssertEqual((-1 as Decimal).magnitude, abs(1 as Decimal))
-        XCTAssertEqual(Decimal.leastFiniteMagnitude.magnitude, -Decimal.leastFiniteMagnitude)
+        XCTAssertEqual(Decimal.leastFiniteMagnitude.magnitude, -Decimal.leastFiniteMagnitude) // A bit of a misnomer.
         XCTAssertEqual(Decimal.greatestFiniteMagnitude.magnitude, Decimal.greatestFiniteMagnitude)
         XCTAssertTrue(Decimal.nan.magnitude.isNaN)
 

Tests/Foundation/Tests/TestJSONSerialization.swift

@@ -1428,8 +1428,6 @@ extension TestJSONSerialization {
     }
 
     func test_serialize_Decimal() {
-        XCTAssertEqual(try trySerialize([-Decimal.leastFiniteMagnitude]), "[0]")
-        XCTAssertEqual(try trySerialize([Decimal.leastFiniteMagnitude]), "[0]")
         XCTAssertEqual(try trySerialize([-Decimal.leastNonzeroMagnitude]), "[-0.00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000001]")
         XCTAssertEqual(try trySerialize([Decimal.leastNonzeroMagnitude]), "[0.00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000001]")
         XCTAssertEqual(try trySerialize([-Decimal.greatestFiniteMagnitude]), "[-3402823669209384634633746074317682114550000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000]")