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

xwu · xwu · commit 405aaecfa482 · 2021-08-30T10:19:17.000-04:00
diff --git a/Darwin/Foundation-swiftoverlay/Decimal.swift b/Darwin/Foundation-swiftoverlay/Decimal.swift
@@ -557,15 +557,11 @@ 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
@@ -725,15 +725,11 @@ 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
`@@ -557,15 +557,11 @@ extension Decimal {`
`557`	`557`	`}`
`558`	`558`
`559`	`559`	`public var nextUp: Decimal {`
`560`		`- return self + Decimal(`
`561`		`- _exponent: _exponent, _length: 1, _isNegative: 0, _isCompact: 1,`
`562`		`- _reserved: 0, _mantissa: (0x0001, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000))`
	`560`	`+ return self + ulp`
`563`	`561`	`}`
`564`	`562`
`565`	`563`	`public var nextDown: Decimal {`
`566`		`- return self - Decimal(`
`567`		`- _exponent: _exponent, _length: 1, _isNegative: 0, _isCompact: 1,`
`568`		`- _reserved: 0, _mantissa: (0x0001, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000))`
	`564`	`+ return -(-self).nextUp`
`569`	`565`	`}`
`570`	`566`
`571`	`567`	`/// The IEEE 754 "class" of this type.`
Original file line number	Diff line number	Diff line change
`@@ -725,15 +725,11 @@ extension Decimal {`
`725`	`725`	`}`
`726`	`726`
`727`	`727`	`public var nextUp: Decimal {`
`728`		`- return self + Decimal(`
`729`		`- _exponent: _exponent, _length: 1, _isNegative: 0, _isCompact: 1,`
`730`		`- _reserved: 0, _mantissa: (0x0001, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000))`
	`728`	`+ return self + ulp`
`731`	`729`	`}`
`732`	`730`
`733`	`731`	`public var nextDown: Decimal {`
`734`		`- return self - Decimal(`
`735`		`- _exponent: _exponent, _length: 1, _isNegative: 0, _isCompact: 1,`
`736`		`- _reserved: 0, _mantissa: (0x0001, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000))`
	`732`	`+ return -(-self).nextUp`
`737`	`733`	`}`
`738`	`734`
`739`	`735`	`/// The IEEE 754 "class" of this type.`