isScalar needs to reject invalid ASCII

AZero13 · AZero13 · commit 928a55721baa · 2025-12-19T23:16:11.000-05:00
0x80 - 0xFF are invalid ascii, and thus, need to not return true always.
diff --git a/stdlib/public/core/ASCII.swift b/stdlib/public/core/ASCII.swift
@@ -30,7 +30,7 @@ extension Unicode.ASCII: Unicode.Encoding {
   @inline(__always)
   @inlinable
   public static func _isScalar(_ x: CodeUnit) -> Bool {
-    return true
+    return isASCII(x)
   }
 
   @inline(__always)
diff --git a/test/stdlib/Unicode.swift b/test/stdlib/Unicode.swift
@@ -110,4 +110,12 @@ UnicodeAPIs.test("UTF-8 and UTF-16 queries") {
   }
 }
 
+
+UnicodeAPIs.test("ASCII._isScalar") {
+  expectTrue(ASCII._isScalar(0))
+  expectTrue(ASCII._isScalar(0x7F))
+  expectFalse(ASCII._isScalar(0x80))
+  expectFalse(ASCII._isScalar(0xFF))
+}
+
 runAllTests()

Original file line number	Diff line number	Diff line change
`@@ -30,7 +30,7 @@ extension Unicode.ASCII: Unicode.Encoding {`
`30`	`30`	`@inline(__always)`
`31`	`31`	`@inlinable`
`32`	`32`	`public static func _isScalar(_ x: CodeUnit) -> Bool {`
`33`		`- return true`
	`33`	`+ return isASCII(x)`
`34`	`34`	`}`
`35`	`35`
`36`	`36`	`@inline(__always)`
Original file line number	Diff line number	Diff line change
`@@ -110,4 +110,12 @@ UnicodeAPIs.test("UTF-8 and UTF-16 queries") {`
`110`	`110`	`}`
`111`	`111`	`}`
`112`	`112`
	`113`	`+`
	`114`	`+UnicodeAPIs.test("ASCII._isScalar") {`
	`115`	`+ expectTrue(ASCII._isScalar(0))`
	`116`	`+ expectTrue(ASCII._isScalar(0x7F))`
	`117`	`+ expectFalse(ASCII._isScalar(0x80))`
	`118`	`+ expectFalse(ASCII._isScalar(0xFF))`
	`119`	`+}`
	`120`	`+`
`113`	`121`	`runAllTests()`