Generic ~= operator

Make `~=` generic over `RegexComponent` so that one can use builder components, e.g. `OneOrMore(...)`, or custom-consuming regex components as patterns.

Author: rxwei

Sources/_StringProcessing/Regex/Match.swift

@@ -187,13 +187,15 @@ extension Regex {
 }
 
 @available(SwiftStdlib 5.7, *)
-public func ~=<Output>(regex: Regex<Output>, input: String) -> Bool {
-  guard let _ = try? regex.wholeMatch(in: input) else { return false }
+@_disfavoredOverload // disambiguate from equatable patterns
+public func ~=<R: RegexComponent>(regex: R, input: String) -> Bool {
+  guard let _ = input.wholeMatch(of: regex) else { return false }
   return true
 }
 
 @available(SwiftStdlib 5.7, *)
-public func ~=<Output>(regex: Regex<Output>, input: Substring) -> Bool {
-  guard let _ = try? regex.wholeMatch(in: input) else { return false }
+@_disfavoredOverload // disambiguate from equatable patterns
+public func ~=<R: RegexComponent>(regex: R, input: Substring) -> Bool {
+  guard let _ = input.wholeMatch(of: regex) else { return false }
   return true
 }

Tests/RegexBuilderTests/AlgorithmsTests.swift

@@ -104,4 +104,38 @@ class RegexConsumerTests: XCTestCase {
        result: "9+16, 3, 10, 99+1")
     )
   }
+
+  func testSwitches() {
+    switch "abcde" {
+    case Regex {
+      "a"
+      ZeroOrMore(.any)
+      "f"
+    }:
+      XCTFail()
+
+    case "abc":
+      XCTFail()
+
+    case Regex {
+      "a"
+      "b"
+      "c"
+    }:
+      XCTFail()
+
+    case Regex {
+      "a"
+      ZeroOrMore(.any)
+      "e"
+    }:
+      break // success
+
+    case OneOrMore(.word):
+      break // success
+
+    default:
+      XCTFail()
+    }
+  }
 }