Simplify expression ID unpacking (const-hoist)

grynspan · grynspan · commit 141f629d6d95 · 2024-12-10T00:21:28.000-05:00
diff --git a/Sources/Testing/SourceAttribution/ExpressionID.swift b/Sources/Testing/SourceAttribution/ExpressionID.swift
@@ -42,10 +42,10 @@ public struct __ExpressionID: Sendable {
     return nybbles
       .enumerated()
       .flatMap { i, nybble in
-        (0 ..< Self._bitsPerNybble).lazy
+        let nybbleOffset = i * Self._bitsPerNybble
+        return (0 ..< Self._bitsPerNybble).lazy
           .filter { (nybble & (1 << $0)) != 0 }
-          .map { (i * Self._bitsPerNybble) + $0 }
-          .map(UInt32.init)
+          .map { UInt32(nybbleOffset + $0) }
       }
   }
 }

Original file line number	Diff line number	Diff line change
`@@ -42,10 +42,10 @@ public struct __ExpressionID: Sendable {`
`42`	`42`	`return nybbles`
`43`	`43`	`.enumerated()`
`44`	`44`	`.flatMap { i, nybble in`
`45`		`- (0 ..< Self._bitsPerNybble).lazy`
	`45`	`+ let nybbleOffset = i * Self._bitsPerNybble`
	`46`	`+ return (0 ..< Self._bitsPerNybble).lazy`
`46`	`47`	`.filter { (nybble & (1 << $0)) != 0 }`
`47`		`- .map { (i * Self._bitsPerNybble) + $0 }`
`48`		`- .map(UInt32.init)`
	`48`	`+ .map { UInt32(nybbleOffset + $0) }`
`49`	`49`	`}`
`50`	`50`	`}`
`51`	`51`	`}`