Use 'Decimal.ulp' to compute 'nextUp' and 'nextDown'.

xwu · xwu · commit 662217d30749 · 2021-08-29T09:52:37.000-04:00
diff --git a/Darwin/Foundation-swiftoverlay/Decimal.swift b/Darwin/Foundation-swiftoverlay/Decimal.swift
@@ -508,15 +508,11 @@ extension Decimal {
     }
 
     public var nextUp: Decimal {
-        return self + Decimal(
-            _exponent: _exponent, _length: 1, _isNegative: 0, _isCompact: 1,
-            _reserved: 0, _mantissa: (0x0001, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000))
+        return self + ulp
     }
 
     public var nextDown: Decimal {
-        return self - Decimal(
-            _exponent: _exponent, _length: 1, _isNegative: 0, _isCompact: 1,
-            _reserved: 0, _mantissa: (0x0001, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000))
+        return -(-self).nextUp
     }
 
     /// The IEEE 754 "class" of this type.
diff --git a/Sources/Foundation/Decimal.swift b/Sources/Foundation/Decimal.swift
@@ -736,15 +736,11 @@ extension Decimal {
     }
 
     public var nextUp: Decimal {
-        return self + Decimal(
-            _exponent: _exponent, _length: 1, _isNegative: 0, _isCompact: 1,
-            _reserved: 0, _mantissa: (0x0001, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000))
+        return self + ulp
     }
 
     public var nextDown: Decimal {
-        return self - Decimal(
-            _exponent: _exponent, _length: 1, _isNegative: 0, _isCompact: 1,
-            _reserved: 0, _mantissa: (0x0001, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000))
+        return -(-self).nextUp
     }
 
     /// The IEEE 754 "class" of this type.

Original file line number	Diff line number	Diff line change
`@@ -508,15 +508,11 @@ extension Decimal {`
`508`	`508`	`}`
`509`	`509`
`510`	`510`	`public var nextUp: Decimal {`
`511`		`- return self + Decimal(`
`512`		`- _exponent: _exponent, _length: 1, _isNegative: 0, _isCompact: 1,`
`513`		`- _reserved: 0, _mantissa: (0x0001, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000))`
	`511`	`+ return self + ulp`
`514`	`512`	`}`
`515`	`513`
`516`	`514`	`public var nextDown: Decimal {`
`517`		`- return self - Decimal(`
`518`		`- _exponent: _exponent, _length: 1, _isNegative: 0, _isCompact: 1,`
`519`		`- _reserved: 0, _mantissa: (0x0001, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000))`
	`515`	`+ return -(-self).nextUp`
`520`	`516`	`}`
`521`	`517`
`522`	`518`	`/// The IEEE 754 "class" of this type.`
Original file line number	Diff line number	Diff line change
`@@ -736,15 +736,11 @@ extension Decimal {`
`736`	`736`	`}`
`737`	`737`
`738`	`738`	`public var nextUp: Decimal {`
`739`		`- return self + Decimal(`
`740`		`- _exponent: _exponent, _length: 1, _isNegative: 0, _isCompact: 1,`
`741`		`- _reserved: 0, _mantissa: (0x0001, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000))`
	`739`	`+ return self + ulp`
`742`	`740`	`}`
`743`	`741`
`744`	`742`	`public var nextDown: Decimal {`
`745`		`- return self - Decimal(`
`746`		`- _exponent: _exponent, _length: 1, _isNegative: 0, _isCompact: 1,`
`747`		`- _reserved: 0, _mantissa: (0x0001, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000))`
	`743`	`+ return -(-self).nextUp`
`748`	`744`	`}`
`749`	`745`
`750`	`746`	`/// The IEEE 754 "class" of this type.`