Character comparison operators.

Author: John Holdsworth

stdlib/private/StdlibUnicodeUnittest/StdlibUnicodeUnittest.swift

@@ -142,11 +142,11 @@ public struct UTFTest {
   public let loc: SourceLoc
 
   public var utf32: [UInt32] {
-    return unicodeScalars.map(UInt32.init)
+    return unicodeScalars.map({ s in UInt32(s) })
   }
 
   public var utf32RepairedTail: [UInt32] {
-    return unicodeScalarsRepairedTail.map(UInt32.init)
+    return unicodeScalarsRepairedTail.map({ s in UInt32(s) })
   }
 
   public init(

stdlib/public/core/IntegerTypes.swift.gyb

@@ -1786,6 +1786,14 @@ ${operatorComment(x.operator, True)}
   }
 }
 
+extension ${Self} {
+  /// Construct with value `v.value`.
+  @inlinable @_alwaysEmitIntoClient
+  public init(unicode v: Unicode.Scalar) {
+    self = ${Self}(v.value)
+  }
+}
+
 
 extension ${Self}: Sendable { }
 

stdlib/public/core/UnicodeScalar.swift

@@ -380,6 +380,62 @@ extension UInt64 {
   }
 }
 
+/// Allows direct comparisons between UInt8 and double quoted literals.
+extension UInt8 {
+  /// Basic comparison operators
+  @_transparent @_alwaysEmitIntoClient
+  public static func == (i: Self, s: Unicode.Scalar) -> Bool {
+    return i == UInt8(ascii: s)
+  }
+  @_transparent @_alwaysEmitIntoClient
+  public static func != (i: Self, s: Unicode.Scalar) -> Bool {
+    return i != UInt8(ascii: s)
+  }
+  @_transparent @_alwaysEmitIntoClient
+  public static func <= (i: Self, s: Unicode.Scalar) -> Bool {
+    return i <= UInt8(ascii: s)
+  }
+  @_transparent @_alwaysEmitIntoClient
+  public static func >= (i: Self, s: Unicode.Scalar) -> Bool {
+    return i >= UInt8(ascii: s)
+  }
+  @_transparent @_alwaysEmitIntoClient
+  public static func < (i: Self, s: Unicode.Scalar) -> Bool {
+    return i < UInt8(ascii: s)
+  }
+  @_transparent @_alwaysEmitIntoClient
+  public static func > (i: Self, s: Unicode.Scalar) -> Bool {
+    return i > UInt8(ascii: s)
+  }
+  /// Used in switch statements
+  @_transparent @_alwaysEmitIntoClient
+  public static func ~= (s: Unicode.Scalar, i: Self) -> Bool {
+    return i == UInt8(ascii: s)
+  }
+  /// Useful now and then
+  @_transparent @_alwaysEmitIntoClient
+  public static func - (i: Self, s: Unicode.Scalar) -> Self {
+    return i - UInt8(ascii: s)
+  }
+}
+
+extension UInt8? {
+  /// Basic equality operators
+  @_transparent @_alwaysEmitIntoClient
+  public static func == (i: Self, s: Unicode.Scalar) -> Bool {
+    return i == UInt8(ascii: s)
+  }
+  @_transparent @_alwaysEmitIntoClient
+  public static func != (i: Self, s: Unicode.Scalar) -> Bool {
+    return i != UInt8(ascii: s)
+  }
+  /// Used in switch statements
+  @_transparent @_alwaysEmitIntoClient
+  public static func ~= (s: Unicode.Scalar, i: Self) -> Bool {
+    return i == UInt8(ascii: s)
+  }
+}
+
 extension Unicode.Scalar: Equatable {
   @inlinable
   public static func == (lhs: Unicode.Scalar, rhs: Unicode.Scalar) -> Bool {