diff --git a/Sources/RegexBuilder/Variadics.swift b/Sources/RegexBuilder/Variadics.swift
index 989e5d463..2f4a6240a 100644
--- a/Sources/RegexBuilder/Variadics.swift
+++ b/Sources/RegexBuilder/Variadics.swift
@@ -2255,35 +2255,6 @@ extension Capture {
     self.init(node: .capture(reference: reference.id, component.regex.root))
   }
 
-  @_disfavoredOverload
-  public init<R: RegexComponent, W, NewCapture>(
-    _ component: R,
-    transform: @escaping (Substring) -> NewCapture
-  ) where Output == (Substring, NewCapture), R.Output == W {
-    self.init(node: .capture(.transform(
-      CaptureTransform(resultType: NewCapture.self) {
-        transform($0) as Any
-      },
-      component.regex.root)))
-  }
-
-  @_disfavoredOverload
-  public init<R: RegexComponent, W, NewCapture>(
-    _ component: R,
-    as reference: Reference<NewCapture>,
-    transform: @escaping (Substring) -> NewCapture
-  ) where Output == (Substring, NewCapture), R.Output == W {
-    self.init(node: .capture(
-      reference: reference.id,
-      .transform(
-        CaptureTransform(resultType: NewCapture.self) {
-          transform($0) as Any
-        },
-        component.regex.root)))
-  }
-}
-
-extension TryCapture {
   @_disfavoredOverload
   public init<R: RegexComponent, W, NewCapture>(
     _ component: R,
@@ -2310,15 +2281,17 @@ extension TryCapture {
         },
         component.regex.root)))
   }
+}
 
+extension TryCapture {
   @_disfavoredOverload
   public init<R: RegexComponent, W, NewCapture>(
     _ component: R,
-    transform: @escaping (Substring) -> NewCapture?
+    transform: @escaping (Substring) throws -> NewCapture?
   ) where Output == (Substring, NewCapture), R.Output == W {
     self.init(node: .capture(.transform(
       CaptureTransform(resultType: NewCapture.self) {
-        transform($0) as Any?
+        try transform($0) as Any?
       },
       component.regex.root)))
   }
@@ -2327,13 +2300,13 @@ extension TryCapture {
   public init<R: RegexComponent, W, NewCapture>(
     _ component: R,
     as reference: Reference<NewCapture>,
-    transform: @escaping (Substring) -> NewCapture?
+    transform: @escaping (Substring) throws -> NewCapture?
   ) where Output == (Substring, NewCapture), R.Output == W {
     self.init(node: .capture(
       reference: reference.id,
       .transform(
         CaptureTransform(resultType: NewCapture.self) {
-          transform($0) as Any?
+          try transform($0) as Any?
         },
         component.regex.root)))
   }
@@ -2359,35 +2332,6 @@ extension Capture {
       component().regex.root))
   }
 
-  @_disfavoredOverload
-  public init<R: RegexComponent, W, NewCapture>(
-    @RegexComponentBuilder _ component: () -> R,
-    transform: @escaping (Substring) -> NewCapture
-  ) where Output == (Substring, NewCapture), R.Output == W {
-    self.init(node: .capture(.transform(
-      CaptureTransform(resultType: NewCapture.self) {
-        transform($0) as Any
-      },
-      component().regex.root)))
-  }
-
-  @_disfavoredOverload
-  public init<R: RegexComponent, W, NewCapture>(
-    as reference: Reference<NewCapture>,
-    @RegexComponentBuilder _ component: () -> R,
-    transform: @escaping (Substring) -> NewCapture
-  ) where Output == (Substring, NewCapture), R.Output == W {
-    self.init(node: .capture(
-      reference: reference.id,
-      .transform(
-        CaptureTransform(resultType: NewCapture.self) {
-          transform($0) as Any
-        },
-        component().regex.root)))
-  }
-}
-
-extension TryCapture {
   @_disfavoredOverload
   public init<R: RegexComponent, W, NewCapture>(
     @RegexComponentBuilder _ component: () -> R,
@@ -2414,15 +2358,17 @@ extension TryCapture {
         },
         component().regex.root)))
   }
+}
 
+extension TryCapture {
   @_disfavoredOverload
   public init<R: RegexComponent, W, NewCapture>(
     @RegexComponentBuilder _ component: () -> R,
-    transform: @escaping (Substring) -> NewCapture?
+    transform: @escaping (Substring) throws -> NewCapture?
   ) where Output == (Substring, NewCapture), R.Output == W {
     self.init(node: .capture(.transform(
       CaptureTransform(resultType: NewCapture.self) {
-        transform($0) as Any?
+        try transform($0) as Any?
       },
       component().regex.root)))
   }
@@ -2431,13 +2377,13 @@ extension TryCapture {
   public init<R: RegexComponent, W, NewCapture>(
     as reference: Reference<NewCapture>,
     @RegexComponentBuilder _ component: () -> R,
-    transform: @escaping (Substring) -> NewCapture?
+    transform: @escaping (Substring) throws -> NewCapture?
   ) where Output == (Substring, NewCapture), R.Output == W {
     self.init(node: .capture(
       reference: reference.id,
       .transform(
         CaptureTransform(resultType: NewCapture.self) {
-          transform($0) as Any?
+          try transform($0) as Any?
         },
         component().regex.root)))
   }
@@ -2458,33 +2404,6 @@ extension Capture {
     self.init(node: .capture(reference: reference.id, component.regex.root))
   }
 
-    public init<R: RegexComponent, W, C0, NewCapture>(
-    _ component: R,
-    transform: @escaping (Substring) -> NewCapture
-  ) where Output == (Substring, NewCapture, C0), R.Output == (W, C0) {
-    self.init(node: .capture(.transform(
-      CaptureTransform(resultType: NewCapture.self) {
-        transform($0) as Any
-      },
-      component.regex.root)))
-  }
-
-    public init<R: RegexComponent, W, C0, NewCapture>(
-    _ component: R,
-    as reference: Reference<NewCapture>,
-    transform: @escaping (Substring) -> NewCapture
-  ) where Output == (Substring, NewCapture, C0), R.Output == (W, C0) {
-    self.init(node: .capture(
-      reference: reference.id,
-      .transform(
-        CaptureTransform(resultType: NewCapture.self) {
-          transform($0) as Any
-        },
-        component.regex.root)))
-  }
-}
-
-extension TryCapture {
     public init<R: RegexComponent, W, C0, NewCapture>(
     _ component: R,
     transform: @escaping (Substring) throws -> NewCapture
@@ -2509,14 +2428,16 @@ extension TryCapture {
         },
         component.regex.root)))
   }
+}
 
+extension TryCapture {
     public init<R: RegexComponent, W, C0, NewCapture>(
     _ component: R,
-    transform: @escaping (Substring) -> NewCapture?
+    transform: @escaping (Substring) throws -> NewCapture?
   ) where Output == (Substring, NewCapture, C0), R.Output == (W, C0) {
     self.init(node: .capture(.transform(
       CaptureTransform(resultType: NewCapture.self) {
-        transform($0) as Any?
+        try transform($0) as Any?
       },
       component.regex.root)))
   }
@@ -2524,13 +2445,13 @@ extension TryCapture {
     public init<R: RegexComponent, W, C0, NewCapture>(
     _ component: R,
     as reference: Reference<NewCapture>,
-    transform: @escaping (Substring) -> NewCapture?
+    transform: @escaping (Substring) throws -> NewCapture?
   ) where Output == (Substring, NewCapture, C0), R.Output == (W, C0) {
     self.init(node: .capture(
       reference: reference.id,
       .transform(
         CaptureTransform(resultType: NewCapture.self) {
-          transform($0) as Any?
+          try transform($0) as Any?
         },
         component.regex.root)))
   }
@@ -2554,33 +2475,6 @@ extension Capture {
       component().regex.root))
   }
 
-    public init<R: RegexComponent, W, C0, NewCapture>(
-    @RegexComponentBuilder _ component: () -> R,
-    transform: @escaping (Substring) -> NewCapture
-  ) where Output == (Substring, NewCapture, C0), R.Output == (W, C0) {
-    self.init(node: .capture(.transform(
-      CaptureTransform(resultType: NewCapture.self) {
-        transform($0) as Any
-      },
-      component().regex.root)))
-  }
-
-    public init<R: RegexComponent, W, C0, NewCapture>(
-    as reference: Reference<NewCapture>,
-    @RegexComponentBuilder _ component: () -> R,
-    transform: @escaping (Substring) -> NewCapture
-  ) where Output == (Substring, NewCapture, C0), R.Output == (W, C0) {
-    self.init(node: .capture(
-      reference: reference.id,
-      .transform(
-        CaptureTransform(resultType: NewCapture.self) {
-          transform($0) as Any
-        },
-        component().regex.root)))
-  }
-}
-
-extension TryCapture {
     public init<R: RegexComponent, W, C0, NewCapture>(
     @RegexComponentBuilder _ component: () -> R,
     transform: @escaping (Substring) throws -> NewCapture
@@ -2605,14 +2499,16 @@ extension TryCapture {
         },
         component().regex.root)))
   }
+}
 
+extension TryCapture {
     public init<R: RegexComponent, W, C0, NewCapture>(
     @RegexComponentBuilder _ component: () -> R,
-    transform: @escaping (Substring) -> NewCapture?
+    transform: @escaping (Substring) throws -> NewCapture?
   ) where Output == (Substring, NewCapture, C0), R.Output == (W, C0) {
     self.init(node: .capture(.transform(
       CaptureTransform(resultType: NewCapture.self) {
-        transform($0) as Any?
+        try transform($0) as Any?
       },
       component().regex.root)))
   }
@@ -2620,13 +2516,13 @@ extension TryCapture {
     public init<R: RegexComponent, W, C0, NewCapture>(
     as reference: Reference<NewCapture>,
     @RegexComponentBuilder _ component: () -> R,
-    transform: @escaping (Substring) -> NewCapture?
+    transform: @escaping (Substring) throws -> NewCapture?
   ) where Output == (Substring, NewCapture, C0), R.Output == (W, C0) {
     self.init(node: .capture(
       reference: reference.id,
       .transform(
         CaptureTransform(resultType: NewCapture.self) {
-          transform($0) as Any?
+          try transform($0) as Any?
         },
         component().regex.root)))
   }
@@ -2647,33 +2543,6 @@ extension Capture {
     self.init(node: .capture(reference: reference.id, component.regex.root))
   }
 
-    public init<R: RegexComponent, W, C0, C1, NewCapture>(
-    _ component: R,
-    transform: @escaping (Substring) -> NewCapture
-  ) where Output == (Substring, NewCapture, C0, C1), R.Output == (W, C0, C1) {
-    self.init(node: .capture(.transform(
-      CaptureTransform(resultType: NewCapture.self) {
-        transform($0) as Any
-      },
-      component.regex.root)))
-  }
-
-    public init<R: RegexComponent, W, C0, C1, NewCapture>(
-    _ component: R,
-    as reference: Reference<NewCapture>,
-    transform: @escaping (Substring) -> NewCapture
-  ) where Output == (Substring, NewCapture, C0, C1), R.Output == (W, C0, C1) {
-    self.init(node: .capture(
-      reference: reference.id,
-      .transform(
-        CaptureTransform(resultType: NewCapture.self) {
-          transform($0) as Any
-        },
-        component.regex.root)))
-  }
-}
-
-extension TryCapture {
     public init<R: RegexComponent, W, C0, C1, NewCapture>(
     _ component: R,
     transform: @escaping (Substring) throws -> NewCapture
@@ -2698,14 +2567,16 @@ extension TryCapture {
         },
         component.regex.root)))
   }
+}
 
+extension TryCapture {
     public init<R: RegexComponent, W, C0, C1, NewCapture>(
     _ component: R,
-    transform: @escaping (Substring) -> NewCapture?
+    transform: @escaping (Substring) throws -> NewCapture?
   ) where Output == (Substring, NewCapture, C0, C1), R.Output == (W, C0, C1) {
     self.init(node: .capture(.transform(
       CaptureTransform(resultType: NewCapture.self) {
-        transform($0) as Any?
+        try transform($0) as Any?
       },
       component.regex.root)))
   }
@@ -2713,13 +2584,13 @@ extension TryCapture {
     public init<R: RegexComponent, W, C0, C1, NewCapture>(
     _ component: R,
     as reference: Reference<NewCapture>,
-    transform: @escaping (Substring) -> NewCapture?
+    transform: @escaping (Substring) throws -> NewCapture?
   ) where Output == (Substring, NewCapture, C0, C1), R.Output == (W, C0, C1) {
     self.init(node: .capture(
       reference: reference.id,
       .transform(
         CaptureTransform(resultType: NewCapture.self) {
-          transform($0) as Any?
+          try transform($0) as Any?
         },
         component.regex.root)))
   }
@@ -2743,33 +2614,6 @@ extension Capture {
       component().regex.root))
   }
 
-    public init<R: RegexComponent, W, C0, C1, NewCapture>(
-    @RegexComponentBuilder _ component: () -> R,
-    transform: @escaping (Substring) -> NewCapture
-  ) where Output == (Substring, NewCapture, C0, C1), R.Output == (W, C0, C1) {
-    self.init(node: .capture(.transform(
-      CaptureTransform(resultType: NewCapture.self) {
-        transform($0) as Any
-      },
-      component().regex.root)))
-  }
-
-    public init<R: RegexComponent, W, C0, C1, NewCapture>(
-    as reference: Reference<NewCapture>,
-    @RegexComponentBuilder _ component: () -> R,
-    transform: @escaping (Substring) -> NewCapture
-  ) where Output == (Substring, NewCapture, C0, C1), R.Output == (W, C0, C1) {
-    self.init(node: .capture(
-      reference: reference.id,
-      .transform(
-        CaptureTransform(resultType: NewCapture.self) {
-          transform($0) as Any
-        },
-        component().regex.root)))
-  }
-}
-
-extension TryCapture {
     public init<R: RegexComponent, W, C0, C1, NewCapture>(
     @RegexComponentBuilder _ component: () -> R,
     transform: @escaping (Substring) throws -> NewCapture
@@ -2794,14 +2638,16 @@ extension TryCapture {
         },
         component().regex.root)))
   }
+}
 
+extension TryCapture {
     public init<R: RegexComponent, W, C0, C1, NewCapture>(
     @RegexComponentBuilder _ component: () -> R,
-    transform: @escaping (Substring) -> NewCapture?
+    transform: @escaping (Substring) throws -> NewCapture?
   ) where Output == (Substring, NewCapture, C0, C1), R.Output == (W, C0, C1) {
     self.init(node: .capture(.transform(
       CaptureTransform(resultType: NewCapture.self) {
-        transform($0) as Any?
+        try transform($0) as Any?
       },
       component().regex.root)))
   }
@@ -2809,13 +2655,13 @@ extension TryCapture {
     public init<R: RegexComponent, W, C0, C1, NewCapture>(
     as reference: Reference<NewCapture>,
     @RegexComponentBuilder _ component: () -> R,
-    transform: @escaping (Substring) -> NewCapture?
+    transform: @escaping (Substring) throws -> NewCapture?
   ) where Output == (Substring, NewCapture, C0, C1), R.Output == (W, C0, C1) {
     self.init(node: .capture(
       reference: reference.id,
       .transform(
         CaptureTransform(resultType: NewCapture.self) {
-          transform($0) as Any?
+          try transform($0) as Any?
         },
         component().regex.root)))
   }
@@ -2836,33 +2682,6 @@ extension Capture {
     self.init(node: .capture(reference: reference.id, component.regex.root))
   }
 
-    public init<R: RegexComponent, W, C0, C1, C2, NewCapture>(
-    _ component: R,
-    transform: @escaping (Substring) -> NewCapture
-  ) where Output == (Substring, NewCapture, C0, C1, C2), R.Output == (W, C0, C1, C2) {
-    self.init(node: .capture(.transform(
-      CaptureTransform(resultType: NewCapture.self) {
-        transform($0) as Any
-      },
-      component.regex.root)))
-  }
-
-    public init<R: RegexComponent, W, C0, C1, C2, NewCapture>(
-    _ component: R,
-    as reference: Reference<NewCapture>,
-    transform: @escaping (Substring) -> NewCapture
-  ) where Output == (Substring, NewCapture, C0, C1, C2), R.Output == (W, C0, C1, C2) {
-    self.init(node: .capture(
-      reference: reference.id,
-      .transform(
-        CaptureTransform(resultType: NewCapture.self) {
-          transform($0) as Any
-        },
-        component.regex.root)))
-  }
-}
-
-extension TryCapture {
     public init<R: RegexComponent, W, C0, C1, C2, NewCapture>(
     _ component: R,
     transform: @escaping (Substring) throws -> NewCapture
@@ -2887,14 +2706,16 @@ extension TryCapture {
         },
         component.regex.root)))
   }
+}
 
+extension TryCapture {
     public init<R: RegexComponent, W, C0, C1, C2, NewCapture>(
     _ component: R,
-    transform: @escaping (Substring) -> NewCapture?
+    transform: @escaping (Substring) throws -> NewCapture?
   ) where Output == (Substring, NewCapture, C0, C1, C2), R.Output == (W, C0, C1, C2) {
     self.init(node: .capture(.transform(
       CaptureTransform(resultType: NewCapture.self) {
-        transform($0) as Any?
+        try transform($0) as Any?
       },
       component.regex.root)))
   }
@@ -2902,13 +2723,13 @@ extension TryCapture {
     public init<R: RegexComponent, W, C0, C1, C2, NewCapture>(
     _ component: R,
     as reference: Reference<NewCapture>,
-    transform: @escaping (Substring) -> NewCapture?
+    transform: @escaping (Substring) throws -> NewCapture?
   ) where Output == (Substring, NewCapture, C0, C1, C2), R.Output == (W, C0, C1, C2) {
     self.init(node: .capture(
       reference: reference.id,
       .transform(
         CaptureTransform(resultType: NewCapture.self) {
-          transform($0) as Any?
+          try transform($0) as Any?
         },
         component.regex.root)))
   }
@@ -2932,33 +2753,6 @@ extension Capture {
       component().regex.root))
   }
 
-    public init<R: RegexComponent, W, C0, C1, C2, NewCapture>(
-    @RegexComponentBuilder _ component: () -> R,
-    transform: @escaping (Substring) -> NewCapture
-  ) where Output == (Substring, NewCapture, C0, C1, C2), R.Output == (W, C0, C1, C2) {
-    self.init(node: .capture(.transform(
-      CaptureTransform(resultType: NewCapture.self) {
-        transform($0) as Any
-      },
-      component().regex.root)))
-  }
-
-    public init<R: RegexComponent, W, C0, C1, C2, NewCapture>(
-    as reference: Reference<NewCapture>,
-    @RegexComponentBuilder _ component: () -> R,
-    transform: @escaping (Substring) -> NewCapture
-  ) where Output == (Substring, NewCapture, C0, C1, C2), R.Output == (W, C0, C1, C2) {
-    self.init(node: .capture(
-      reference: reference.id,
-      .transform(
-        CaptureTransform(resultType: NewCapture.self) {
-          transform($0) as Any
-        },
-        component().regex.root)))
-  }
-}
-
-extension TryCapture {
     public init<R: RegexComponent, W, C0, C1, C2, NewCapture>(
     @RegexComponentBuilder _ component: () -> R,
     transform: @escaping (Substring) throws -> NewCapture
@@ -2983,14 +2777,16 @@ extension TryCapture {
         },
         component().regex.root)))
   }
+}
 
+extension TryCapture {
     public init<R: RegexComponent, W, C0, C1, C2, NewCapture>(
     @RegexComponentBuilder _ component: () -> R,
-    transform: @escaping (Substring) -> NewCapture?
+    transform: @escaping (Substring) throws -> NewCapture?
   ) where Output == (Substring, NewCapture, C0, C1, C2), R.Output == (W, C0, C1, C2) {
     self.init(node: .capture(.transform(
       CaptureTransform(resultType: NewCapture.self) {
-        transform($0) as Any?
+        try transform($0) as Any?
       },
       component().regex.root)))
   }
@@ -2998,13 +2794,13 @@ extension TryCapture {
     public init<R: RegexComponent, W, C0, C1, C2, NewCapture>(
     as reference: Reference<NewCapture>,
     @RegexComponentBuilder _ component: () -> R,
-    transform: @escaping (Substring) -> NewCapture?
+    transform: @escaping (Substring) throws -> NewCapture?
   ) where Output == (Substring, NewCapture, C0, C1, C2), R.Output == (W, C0, C1, C2) {
     self.init(node: .capture(
       reference: reference.id,
       .transform(
         CaptureTransform(resultType: NewCapture.self) {
-          transform($0) as Any?
+          try transform($0) as Any?
         },
         component().regex.root)))
   }
@@ -3025,33 +2821,6 @@ extension Capture {
     self.init(node: .capture(reference: reference.id, component.regex.root))
   }
 
-    public init<R: RegexComponent, W, C0, C1, C2, C3, NewCapture>(
-    _ component: R,
-    transform: @escaping (Substring) -> NewCapture
-  ) where Output == (Substring, NewCapture, C0, C1, C2, C3), R.Output == (W, C0, C1, C2, C3) {
-    self.init(node: .capture(.transform(
-      CaptureTransform(resultType: NewCapture.self) {
-        transform($0) as Any
-      },
-      component.regex.root)))
-  }
-
-    public init<R: RegexComponent, W, C0, C1, C2, C3, NewCapture>(
-    _ component: R,
-    as reference: Reference<NewCapture>,
-    transform: @escaping (Substring) -> NewCapture
-  ) where Output == (Substring, NewCapture, C0, C1, C2, C3), R.Output == (W, C0, C1, C2, C3) {
-    self.init(node: .capture(
-      reference: reference.id,
-      .transform(
-        CaptureTransform(resultType: NewCapture.self) {
-          transform($0) as Any
-        },
-        component.regex.root)))
-  }
-}
-
-extension TryCapture {
     public init<R: RegexComponent, W, C0, C1, C2, C3, NewCapture>(
     _ component: R,
     transform: @escaping (Substring) throws -> NewCapture
@@ -3076,14 +2845,16 @@ extension TryCapture {
         },
         component.regex.root)))
   }
+}
 
+extension TryCapture {
     public init<R: RegexComponent, W, C0, C1, C2, C3, NewCapture>(
     _ component: R,
-    transform: @escaping (Substring) -> NewCapture?
+    transform: @escaping (Substring) throws -> NewCapture?
   ) where Output == (Substring, NewCapture, C0, C1, C2, C3), R.Output == (W, C0, C1, C2, C3) {
     self.init(node: .capture(.transform(
       CaptureTransform(resultType: NewCapture.self) {
-        transform($0) as Any?
+        try transform($0) as Any?
       },
       component.regex.root)))
   }
@@ -3091,13 +2862,13 @@ extension TryCapture {
     public init<R: RegexComponent, W, C0, C1, C2, C3, NewCapture>(
     _ component: R,
     as reference: Reference<NewCapture>,
-    transform: @escaping (Substring) -> NewCapture?
+    transform: @escaping (Substring) throws -> NewCapture?
   ) where Output == (Substring, NewCapture, C0, C1, C2, C3), R.Output == (W, C0, C1, C2, C3) {
     self.init(node: .capture(
       reference: reference.id,
       .transform(
         CaptureTransform(resultType: NewCapture.self) {
-          transform($0) as Any?
+          try transform($0) as Any?
         },
         component.regex.root)))
   }
@@ -3121,33 +2892,6 @@ extension Capture {
       component().regex.root))
   }
 
-    public init<R: RegexComponent, W, C0, C1, C2, C3, NewCapture>(
-    @RegexComponentBuilder _ component: () -> R,
-    transform: @escaping (Substring) -> NewCapture
-  ) where Output == (Substring, NewCapture, C0, C1, C2, C3), R.Output == (W, C0, C1, C2, C3) {
-    self.init(node: .capture(.transform(
-      CaptureTransform(resultType: NewCapture.self) {
-        transform($0) as Any
-      },
-      component().regex.root)))
-  }
-
-    public init<R: RegexComponent, W, C0, C1, C2, C3, NewCapture>(
-    as reference: Reference<NewCapture>,
-    @RegexComponentBuilder _ component: () -> R,
-    transform: @escaping (Substring) -> NewCapture
-  ) where Output == (Substring, NewCapture, C0, C1, C2, C3), R.Output == (W, C0, C1, C2, C3) {
-    self.init(node: .capture(
-      reference: reference.id,
-      .transform(
-        CaptureTransform(resultType: NewCapture.self) {
-          transform($0) as Any
-        },
-        component().regex.root)))
-  }
-}
-
-extension TryCapture {
     public init<R: RegexComponent, W, C0, C1, C2, C3, NewCapture>(
     @RegexComponentBuilder _ component: () -> R,
     transform: @escaping (Substring) throws -> NewCapture
@@ -3172,14 +2916,16 @@ extension TryCapture {
         },
         component().regex.root)))
   }
+}
 
+extension TryCapture {
     public init<R: RegexComponent, W, C0, C1, C2, C3, NewCapture>(
     @RegexComponentBuilder _ component: () -> R,
-    transform: @escaping (Substring) -> NewCapture?
+    transform: @escaping (Substring) throws -> NewCapture?
   ) where Output == (Substring, NewCapture, C0, C1, C2, C3), R.Output == (W, C0, C1, C2, C3) {
     self.init(node: .capture(.transform(
       CaptureTransform(resultType: NewCapture.self) {
-        transform($0) as Any?
+        try transform($0) as Any?
       },
       component().regex.root)))
   }
@@ -3187,13 +2933,13 @@ extension TryCapture {
     public init<R: RegexComponent, W, C0, C1, C2, C3, NewCapture>(
     as reference: Reference<NewCapture>,
     @RegexComponentBuilder _ component: () -> R,
-    transform: @escaping (Substring) -> NewCapture?
+    transform: @escaping (Substring) throws -> NewCapture?
   ) where Output == (Substring, NewCapture, C0, C1, C2, C3), R.Output == (W, C0, C1, C2, C3) {
     self.init(node: .capture(
       reference: reference.id,
       .transform(
         CaptureTransform(resultType: NewCapture.self) {
-          transform($0) as Any?
+          try transform($0) as Any?
         },
         component().regex.root)))
   }
@@ -3214,33 +2960,6 @@ extension Capture {
     self.init(node: .capture(reference: reference.id, component.regex.root))
   }
 
-    public init<R: RegexComponent, W, C0, C1, C2, C3, C4, NewCapture>(
-    _ component: R,
-    transform: @escaping (Substring) -> NewCapture
-  ) where Output == (Substring, NewCapture, C0, C1, C2, C3, C4), R.Output == (W, C0, C1, C2, C3, C4) {
-    self.init(node: .capture(.transform(
-      CaptureTransform(resultType: NewCapture.self) {
-        transform($0) as Any
-      },
-      component.regex.root)))
-  }
-
-    public init<R: RegexComponent, W, C0, C1, C2, C3, C4, NewCapture>(
-    _ component: R,
-    as reference: Reference<NewCapture>,
-    transform: @escaping (Substring) -> NewCapture
-  ) where Output == (Substring, NewCapture, C0, C1, C2, C3, C4), R.Output == (W, C0, C1, C2, C3, C4) {
-    self.init(node: .capture(
-      reference: reference.id,
-      .transform(
-        CaptureTransform(resultType: NewCapture.self) {
-          transform($0) as Any
-        },
-        component.regex.root)))
-  }
-}
-
-extension TryCapture {
     public init<R: RegexComponent, W, C0, C1, C2, C3, C4, NewCapture>(
     _ component: R,
     transform: @escaping (Substring) throws -> NewCapture
@@ -3265,14 +2984,16 @@ extension TryCapture {
         },
         component.regex.root)))
   }
+}
 
+extension TryCapture {
     public init<R: RegexComponent, W, C0, C1, C2, C3, C4, NewCapture>(
     _ component: R,
-    transform: @escaping (Substring) -> NewCapture?
+    transform: @escaping (Substring) throws -> NewCapture?
   ) where Output == (Substring, NewCapture, C0, C1, C2, C3, C4), R.Output == (W, C0, C1, C2, C3, C4) {
     self.init(node: .capture(.transform(
       CaptureTransform(resultType: NewCapture.self) {
-        transform($0) as Any?
+        try transform($0) as Any?
       },
       component.regex.root)))
   }
@@ -3280,13 +3001,13 @@ extension TryCapture {
     public init<R: RegexComponent, W, C0, C1, C2, C3, C4, NewCapture>(
     _ component: R,
     as reference: Reference<NewCapture>,
-    transform: @escaping (Substring) -> NewCapture?
+    transform: @escaping (Substring) throws -> NewCapture?
   ) where Output == (Substring, NewCapture, C0, C1, C2, C3, C4), R.Output == (W, C0, C1, C2, C3, C4) {
     self.init(node: .capture(
       reference: reference.id,
       .transform(
         CaptureTransform(resultType: NewCapture.self) {
-          transform($0) as Any?
+          try transform($0) as Any?
         },
         component.regex.root)))
   }
@@ -3306,37 +3027,10 @@ extension Capture {
     @RegexComponentBuilder _ component: () -> R
   ) where Output == (Substring, W, C0, C1, C2, C3, C4), R.Output == (W, C0, C1, C2, C3, C4) {
     self.init(node: .capture(
-      reference: reference.id,
-      component().regex.root))
-  }
-
-    public init<R: RegexComponent, W, C0, C1, C2, C3, C4, NewCapture>(
-    @RegexComponentBuilder _ component: () -> R,
-    transform: @escaping (Substring) -> NewCapture
-  ) where Output == (Substring, NewCapture, C0, C1, C2, C3, C4), R.Output == (W, C0, C1, C2, C3, C4) {
-    self.init(node: .capture(.transform(
-      CaptureTransform(resultType: NewCapture.self) {
-        transform($0) as Any
-      },
-      component().regex.root)))
-  }
-
-    public init<R: RegexComponent, W, C0, C1, C2, C3, C4, NewCapture>(
-    as reference: Reference<NewCapture>,
-    @RegexComponentBuilder _ component: () -> R,
-    transform: @escaping (Substring) -> NewCapture
-  ) where Output == (Substring, NewCapture, C0, C1, C2, C3, C4), R.Output == (W, C0, C1, C2, C3, C4) {
-    self.init(node: .capture(
-      reference: reference.id,
-      .transform(
-        CaptureTransform(resultType: NewCapture.self) {
-          transform($0) as Any
-        },
-        component().regex.root)))
+      reference: reference.id,
+      component().regex.root))
   }
-}
 
-extension TryCapture {
     public init<R: RegexComponent, W, C0, C1, C2, C3, C4, NewCapture>(
     @RegexComponentBuilder _ component: () -> R,
     transform: @escaping (Substring) throws -> NewCapture
@@ -3361,14 +3055,16 @@ extension TryCapture {
         },
         component().regex.root)))
   }
+}
 
+extension TryCapture {
     public init<R: RegexComponent, W, C0, C1, C2, C3, C4, NewCapture>(
     @RegexComponentBuilder _ component: () -> R,
-    transform: @escaping (Substring) -> NewCapture?
+    transform: @escaping (Substring) throws -> NewCapture?
   ) where Output == (Substring, NewCapture, C0, C1, C2, C3, C4), R.Output == (W, C0, C1, C2, C3, C4) {
     self.init(node: .capture(.transform(
       CaptureTransform(resultType: NewCapture.self) {
-        transform($0) as Any?
+        try transform($0) as Any?
       },
       component().regex.root)))
   }
@@ -3376,13 +3072,13 @@ extension TryCapture {
     public init<R: RegexComponent, W, C0, C1, C2, C3, C4, NewCapture>(
     as reference: Reference<NewCapture>,
     @RegexComponentBuilder _ component: () -> R,
-    transform: @escaping (Substring) -> NewCapture?
+    transform: @escaping (Substring) throws -> NewCapture?
   ) where Output == (Substring, NewCapture, C0, C1, C2, C3, C4), R.Output == (W, C0, C1, C2, C3, C4) {
     self.init(node: .capture(
       reference: reference.id,
       .transform(
         CaptureTransform(resultType: NewCapture.self) {
-          transform($0) as Any?
+          try transform($0) as Any?
         },
         component().regex.root)))
   }
@@ -3403,33 +3099,6 @@ extension Capture {
     self.init(node: .capture(reference: reference.id, component.regex.root))
   }
 
-    public init<R: RegexComponent, W, C0, C1, C2, C3, C4, C5, NewCapture>(
-    _ component: R,
-    transform: @escaping (Substring) -> NewCapture
-  ) where Output == (Substring, NewCapture, C0, C1, C2, C3, C4, C5), R.Output == (W, C0, C1, C2, C3, C4, C5) {
-    self.init(node: .capture(.transform(
-      CaptureTransform(resultType: NewCapture.self) {
-        transform($0) as Any
-      },
-      component.regex.root)))
-  }
-
-    public init<R: RegexComponent, W, C0, C1, C2, C3, C4, C5, NewCapture>(
-    _ component: R,
-    as reference: Reference<NewCapture>,
-    transform: @escaping (Substring) -> NewCapture
-  ) where Output == (Substring, NewCapture, C0, C1, C2, C3, C4, C5), R.Output == (W, C0, C1, C2, C3, C4, C5) {
-    self.init(node: .capture(
-      reference: reference.id,
-      .transform(
-        CaptureTransform(resultType: NewCapture.self) {
-          transform($0) as Any
-        },
-        component.regex.root)))
-  }
-}
-
-extension TryCapture {
     public init<R: RegexComponent, W, C0, C1, C2, C3, C4, C5, NewCapture>(
     _ component: R,
     transform: @escaping (Substring) throws -> NewCapture
@@ -3454,14 +3123,16 @@ extension TryCapture {
         },
         component.regex.root)))
   }
+}
 
+extension TryCapture {
     public init<R: RegexComponent, W, C0, C1, C2, C3, C4, C5, NewCapture>(
     _ component: R,
-    transform: @escaping (Substring) -> NewCapture?
+    transform: @escaping (Substring) throws -> NewCapture?
   ) where Output == (Substring, NewCapture, C0, C1, C2, C3, C4, C5), R.Output == (W, C0, C1, C2, C3, C4, C5) {
     self.init(node: .capture(.transform(
       CaptureTransform(resultType: NewCapture.self) {
-        transform($0) as Any?
+        try transform($0) as Any?
       },
       component.regex.root)))
   }
@@ -3469,13 +3140,13 @@ extension TryCapture {
     public init<R: RegexComponent, W, C0, C1, C2, C3, C4, C5, NewCapture>(
     _ component: R,
     as reference: Reference<NewCapture>,
-    transform: @escaping (Substring) -> NewCapture?
+    transform: @escaping (Substring) throws -> NewCapture?
   ) where Output == (Substring, NewCapture, C0, C1, C2, C3, C4, C5), R.Output == (W, C0, C1, C2, C3, C4, C5) {
     self.init(node: .capture(
       reference: reference.id,
       .transform(
         CaptureTransform(resultType: NewCapture.self) {
-          transform($0) as Any?
+          try transform($0) as Any?
         },
         component.regex.root)))
   }
@@ -3499,33 +3170,6 @@ extension Capture {
       component().regex.root))
   }
 
-    public init<R: RegexComponent, W, C0, C1, C2, C3, C4, C5, NewCapture>(
-    @RegexComponentBuilder _ component: () -> R,
-    transform: @escaping (Substring) -> NewCapture
-  ) where Output == (Substring, NewCapture, C0, C1, C2, C3, C4, C5), R.Output == (W, C0, C1, C2, C3, C4, C5) {
-    self.init(node: .capture(.transform(
-      CaptureTransform(resultType: NewCapture.self) {
-        transform($0) as Any
-      },
-      component().regex.root)))
-  }
-
-    public init<R: RegexComponent, W, C0, C1, C2, C3, C4, C5, NewCapture>(
-    as reference: Reference<NewCapture>,
-    @RegexComponentBuilder _ component: () -> R,
-    transform: @escaping (Substring) -> NewCapture
-  ) where Output == (Substring, NewCapture, C0, C1, C2, C3, C4, C5), R.Output == (W, C0, C1, C2, C3, C4, C5) {
-    self.init(node: .capture(
-      reference: reference.id,
-      .transform(
-        CaptureTransform(resultType: NewCapture.self) {
-          transform($0) as Any
-        },
-        component().regex.root)))
-  }
-}
-
-extension TryCapture {
     public init<R: RegexComponent, W, C0, C1, C2, C3, C4, C5, NewCapture>(
     @RegexComponentBuilder _ component: () -> R,
     transform: @escaping (Substring) throws -> NewCapture
@@ -3550,14 +3194,16 @@ extension TryCapture {
         },
         component().regex.root)))
   }
+}
 
+extension TryCapture {
     public init<R: RegexComponent, W, C0, C1, C2, C3, C4, C5, NewCapture>(
     @RegexComponentBuilder _ component: () -> R,
-    transform: @escaping (Substring) -> NewCapture?
+    transform: @escaping (Substring) throws -> NewCapture?
   ) where Output == (Substring, NewCapture, C0, C1, C2, C3, C4, C5), R.Output == (W, C0, C1, C2, C3, C4, C5) {
     self.init(node: .capture(.transform(
       CaptureTransform(resultType: NewCapture.self) {
-        transform($0) as Any?
+        try transform($0) as Any?
       },
       component().regex.root)))
   }
@@ -3565,13 +3211,13 @@ extension TryCapture {
     public init<R: RegexComponent, W, C0, C1, C2, C3, C4, C5, NewCapture>(
     as reference: Reference<NewCapture>,
     @RegexComponentBuilder _ component: () -> R,
-    transform: @escaping (Substring) -> NewCapture?
+    transform: @escaping (Substring) throws -> NewCapture?
   ) where Output == (Substring, NewCapture, C0, C1, C2, C3, C4, C5), R.Output == (W, C0, C1, C2, C3, C4, C5) {
     self.init(node: .capture(
       reference: reference.id,
       .transform(
         CaptureTransform(resultType: NewCapture.self) {
-          transform($0) as Any?
+          try transform($0) as Any?
         },
         component().regex.root)))
   }
@@ -3592,33 +3238,6 @@ extension Capture {
     self.init(node: .capture(reference: reference.id, component.regex.root))
   }
 
-    public init<R: RegexComponent, W, C0, C1, C2, C3, C4, C5, C6, NewCapture>(
-    _ component: R,
-    transform: @escaping (Substring) -> NewCapture
-  ) where Output == (Substring, NewCapture, C0, C1, C2, C3, C4, C5, C6), R.Output == (W, C0, C1, C2, C3, C4, C5, C6) {
-    self.init(node: .capture(.transform(
-      CaptureTransform(resultType: NewCapture.self) {
-        transform($0) as Any
-      },
-      component.regex.root)))
-  }
-
-    public init<R: RegexComponent, W, C0, C1, C2, C3, C4, C5, C6, NewCapture>(
-    _ component: R,
-    as reference: Reference<NewCapture>,
-    transform: @escaping (Substring) -> NewCapture
-  ) where Output == (Substring, NewCapture, C0, C1, C2, C3, C4, C5, C6), R.Output == (W, C0, C1, C2, C3, C4, C5, C6) {
-    self.init(node: .capture(
-      reference: reference.id,
-      .transform(
-        CaptureTransform(resultType: NewCapture.self) {
-          transform($0) as Any
-        },
-        component.regex.root)))
-  }
-}
-
-extension TryCapture {
     public init<R: RegexComponent, W, C0, C1, C2, C3, C4, C5, C6, NewCapture>(
     _ component: R,
     transform: @escaping (Substring) throws -> NewCapture
@@ -3643,14 +3262,16 @@ extension TryCapture {
         },
         component.regex.root)))
   }
+}
 
+extension TryCapture {
     public init<R: RegexComponent, W, C0, C1, C2, C3, C4, C5, C6, NewCapture>(
     _ component: R,
-    transform: @escaping (Substring) -> NewCapture?
+    transform: @escaping (Substring) throws -> NewCapture?
   ) where Output == (Substring, NewCapture, C0, C1, C2, C3, C4, C5, C6), R.Output == (W, C0, C1, C2, C3, C4, C5, C6) {
     self.init(node: .capture(.transform(
       CaptureTransform(resultType: NewCapture.self) {
-        transform($0) as Any?
+        try transform($0) as Any?
       },
       component.regex.root)))
   }
@@ -3658,13 +3279,13 @@ extension TryCapture {
     public init<R: RegexComponent, W, C0, C1, C2, C3, C4, C5, C6, NewCapture>(
     _ component: R,
     as reference: Reference<NewCapture>,
-    transform: @escaping (Substring) -> NewCapture?
+    transform: @escaping (Substring) throws -> NewCapture?
   ) where Output == (Substring, NewCapture, C0, C1, C2, C3, C4, C5, C6), R.Output == (W, C0, C1, C2, C3, C4, C5, C6) {
     self.init(node: .capture(
       reference: reference.id,
       .transform(
         CaptureTransform(resultType: NewCapture.self) {
-          transform($0) as Any?
+          try transform($0) as Any?
         },
         component.regex.root)))
   }
@@ -3688,33 +3309,6 @@ extension Capture {
       component().regex.root))
   }
 
-    public init<R: RegexComponent, W, C0, C1, C2, C3, C4, C5, C6, NewCapture>(
-    @RegexComponentBuilder _ component: () -> R,
-    transform: @escaping (Substring) -> NewCapture
-  ) where Output == (Substring, NewCapture, C0, C1, C2, C3, C4, C5, C6), R.Output == (W, C0, C1, C2, C3, C4, C5, C6) {
-    self.init(node: .capture(.transform(
-      CaptureTransform(resultType: NewCapture.self) {
-        transform($0) as Any
-      },
-      component().regex.root)))
-  }
-
-    public init<R: RegexComponent, W, C0, C1, C2, C3, C4, C5, C6, NewCapture>(
-    as reference: Reference<NewCapture>,
-    @RegexComponentBuilder _ component: () -> R,
-    transform: @escaping (Substring) -> NewCapture
-  ) where Output == (Substring, NewCapture, C0, C1, C2, C3, C4, C5, C6), R.Output == (W, C0, C1, C2, C3, C4, C5, C6) {
-    self.init(node: .capture(
-      reference: reference.id,
-      .transform(
-        CaptureTransform(resultType: NewCapture.self) {
-          transform($0) as Any
-        },
-        component().regex.root)))
-  }
-}
-
-extension TryCapture {
     public init<R: RegexComponent, W, C0, C1, C2, C3, C4, C5, C6, NewCapture>(
     @RegexComponentBuilder _ component: () -> R,
     transform: @escaping (Substring) throws -> NewCapture
@@ -3739,14 +3333,16 @@ extension TryCapture {
         },
         component().regex.root)))
   }
+}
 
+extension TryCapture {
     public init<R: RegexComponent, W, C0, C1, C2, C3, C4, C5, C6, NewCapture>(
     @RegexComponentBuilder _ component: () -> R,
-    transform: @escaping (Substring) -> NewCapture?
+    transform: @escaping (Substring) throws -> NewCapture?
   ) where Output == (Substring, NewCapture, C0, C1, C2, C3, C4, C5, C6), R.Output == (W, C0, C1, C2, C3, C4, C5, C6) {
     self.init(node: .capture(.transform(
       CaptureTransform(resultType: NewCapture.self) {
-        transform($0) as Any?
+        try transform($0) as Any?
       },
       component().regex.root)))
   }
@@ -3754,13 +3350,13 @@ extension TryCapture {
     public init<R: RegexComponent, W, C0, C1, C2, C3, C4, C5, C6, NewCapture>(
     as reference: Reference<NewCapture>,
     @RegexComponentBuilder _ component: () -> R,
-    transform: @escaping (Substring) -> NewCapture?
+    transform: @escaping (Substring) throws -> NewCapture?
   ) where Output == (Substring, NewCapture, C0, C1, C2, C3, C4, C5, C6), R.Output == (W, C0, C1, C2, C3, C4, C5, C6) {
     self.init(node: .capture(
       reference: reference.id,
       .transform(
         CaptureTransform(resultType: NewCapture.self) {
-          transform($0) as Any?
+          try transform($0) as Any?
         },
         component().regex.root)))
   }
@@ -3781,33 +3377,6 @@ extension Capture {
     self.init(node: .capture(reference: reference.id, component.regex.root))
   }
 
-    public init<R: RegexComponent, W, C0, C1, C2, C3, C4, C5, C6, C7, NewCapture>(
-    _ component: R,
-    transform: @escaping (Substring) -> NewCapture
-  ) where Output == (Substring, NewCapture, C0, C1, C2, C3, C4, C5, C6, C7), R.Output == (W, C0, C1, C2, C3, C4, C5, C6, C7) {
-    self.init(node: .capture(.transform(
-      CaptureTransform(resultType: NewCapture.self) {
-        transform($0) as Any
-      },
-      component.regex.root)))
-  }
-
-    public init<R: RegexComponent, W, C0, C1, C2, C3, C4, C5, C6, C7, NewCapture>(
-    _ component: R,
-    as reference: Reference<NewCapture>,
-    transform: @escaping (Substring) -> NewCapture
-  ) where Output == (Substring, NewCapture, C0, C1, C2, C3, C4, C5, C6, C7), R.Output == (W, C0, C1, C2, C3, C4, C5, C6, C7) {
-    self.init(node: .capture(
-      reference: reference.id,
-      .transform(
-        CaptureTransform(resultType: NewCapture.self) {
-          transform($0) as Any
-        },
-        component.regex.root)))
-  }
-}
-
-extension TryCapture {
     public init<R: RegexComponent, W, C0, C1, C2, C3, C4, C5, C6, C7, NewCapture>(
     _ component: R,
     transform: @escaping (Substring) throws -> NewCapture
@@ -3832,14 +3401,16 @@ extension TryCapture {
         },
         component.regex.root)))
   }
+}
 
+extension TryCapture {
     public init<R: RegexComponent, W, C0, C1, C2, C3, C4, C5, C6, C7, NewCapture>(
     _ component: R,
-    transform: @escaping (Substring) -> NewCapture?
+    transform: @escaping (Substring) throws -> NewCapture?
   ) where Output == (Substring, NewCapture, C0, C1, C2, C3, C4, C5, C6, C7), R.Output == (W, C0, C1, C2, C3, C4, C5, C6, C7) {
     self.init(node: .capture(.transform(
       CaptureTransform(resultType: NewCapture.self) {
-        transform($0) as Any?
+        try transform($0) as Any?
       },
       component.regex.root)))
   }
@@ -3847,13 +3418,13 @@ extension TryCapture {
     public init<R: RegexComponent, W, C0, C1, C2, C3, C4, C5, C6, C7, NewCapture>(
     _ component: R,
     as reference: Reference<NewCapture>,
-    transform: @escaping (Substring) -> NewCapture?
+    transform: @escaping (Substring) throws -> NewCapture?
   ) where Output == (Substring, NewCapture, C0, C1, C2, C3, C4, C5, C6, C7), R.Output == (W, C0, C1, C2, C3, C4, C5, C6, C7) {
     self.init(node: .capture(
       reference: reference.id,
       .transform(
         CaptureTransform(resultType: NewCapture.self) {
-          transform($0) as Any?
+          try transform($0) as Any?
         },
         component.regex.root)))
   }
@@ -3877,33 +3448,6 @@ extension Capture {
       component().regex.root))
   }
 
-    public init<R: RegexComponent, W, C0, C1, C2, C3, C4, C5, C6, C7, NewCapture>(
-    @RegexComponentBuilder _ component: () -> R,
-    transform: @escaping (Substring) -> NewCapture
-  ) where Output == (Substring, NewCapture, C0, C1, C2, C3, C4, C5, C6, C7), R.Output == (W, C0, C1, C2, C3, C4, C5, C6, C7) {
-    self.init(node: .capture(.transform(
-      CaptureTransform(resultType: NewCapture.self) {
-        transform($0) as Any
-      },
-      component().regex.root)))
-  }
-
-    public init<R: RegexComponent, W, C0, C1, C2, C3, C4, C5, C6, C7, NewCapture>(
-    as reference: Reference<NewCapture>,
-    @RegexComponentBuilder _ component: () -> R,
-    transform: @escaping (Substring) -> NewCapture
-  ) where Output == (Substring, NewCapture, C0, C1, C2, C3, C4, C5, C6, C7), R.Output == (W, C0, C1, C2, C3, C4, C5, C6, C7) {
-    self.init(node: .capture(
-      reference: reference.id,
-      .transform(
-        CaptureTransform(resultType: NewCapture.self) {
-          transform($0) as Any
-        },
-        component().regex.root)))
-  }
-}
-
-extension TryCapture {
     public init<R: RegexComponent, W, C0, C1, C2, C3, C4, C5, C6, C7, NewCapture>(
     @RegexComponentBuilder _ component: () -> R,
     transform: @escaping (Substring) throws -> NewCapture
@@ -3928,14 +3472,16 @@ extension TryCapture {
         },
         component().regex.root)))
   }
+}
 
+extension TryCapture {
     public init<R: RegexComponent, W, C0, C1, C2, C3, C4, C5, C6, C7, NewCapture>(
     @RegexComponentBuilder _ component: () -> R,
-    transform: @escaping (Substring) -> NewCapture?
+    transform: @escaping (Substring) throws -> NewCapture?
   ) where Output == (Substring, NewCapture, C0, C1, C2, C3, C4, C5, C6, C7), R.Output == (W, C0, C1, C2, C3, C4, C5, C6, C7) {
     self.init(node: .capture(.transform(
       CaptureTransform(resultType: NewCapture.self) {
-        transform($0) as Any?
+        try transform($0) as Any?
       },
       component().regex.root)))
   }
@@ -3943,13 +3489,13 @@ extension TryCapture {
     public init<R: RegexComponent, W, C0, C1, C2, C3, C4, C5, C6, C7, NewCapture>(
     as reference: Reference<NewCapture>,
     @RegexComponentBuilder _ component: () -> R,
-    transform: @escaping (Substring) -> NewCapture?
+    transform: @escaping (Substring) throws -> NewCapture?
   ) where Output == (Substring, NewCapture, C0, C1, C2, C3, C4, C5, C6, C7), R.Output == (W, C0, C1, C2, C3, C4, C5, C6, C7) {
     self.init(node: .capture(
       reference: reference.id,
       .transform(
         CaptureTransform(resultType: NewCapture.self) {
-          transform($0) as Any?
+          try transform($0) as Any?
         },
         component().regex.root)))
   }
@@ -3970,33 +3516,6 @@ extension Capture {
     self.init(node: .capture(reference: reference.id, component.regex.root))
   }
 
-    public init<R: RegexComponent, W, C0, C1, C2, C3, C4, C5, C6, C7, C8, NewCapture>(
-    _ component: R,
-    transform: @escaping (Substring) -> NewCapture
-  ) where Output == (Substring, NewCapture, C0, C1, C2, C3, C4, C5, C6, C7, C8), R.Output == (W, C0, C1, C2, C3, C4, C5, C6, C7, C8) {
-    self.init(node: .capture(.transform(
-      CaptureTransform(resultType: NewCapture.self) {
-        transform($0) as Any
-      },
-      component.regex.root)))
-  }
-
-    public init<R: RegexComponent, W, C0, C1, C2, C3, C4, C5, C6, C7, C8, NewCapture>(
-    _ component: R,
-    as reference: Reference<NewCapture>,
-    transform: @escaping (Substring) -> NewCapture
-  ) where Output == (Substring, NewCapture, C0, C1, C2, C3, C4, C5, C6, C7, C8), R.Output == (W, C0, C1, C2, C3, C4, C5, C6, C7, C8) {
-    self.init(node: .capture(
-      reference: reference.id,
-      .transform(
-        CaptureTransform(resultType: NewCapture.self) {
-          transform($0) as Any
-        },
-        component.regex.root)))
-  }
-}
-
-extension TryCapture {
     public init<R: RegexComponent, W, C0, C1, C2, C3, C4, C5, C6, C7, C8, NewCapture>(
     _ component: R,
     transform: @escaping (Substring) throws -> NewCapture
@@ -4021,14 +3540,16 @@ extension TryCapture {
         },
         component.regex.root)))
   }
+}
 
+extension TryCapture {
     public init<R: RegexComponent, W, C0, C1, C2, C3, C4, C5, C6, C7, C8, NewCapture>(
     _ component: R,
-    transform: @escaping (Substring) -> NewCapture?
+    transform: @escaping (Substring) throws -> NewCapture?
   ) where Output == (Substring, NewCapture, C0, C1, C2, C3, C4, C5, C6, C7, C8), R.Output == (W, C0, C1, C2, C3, C4, C5, C6, C7, C8) {
     self.init(node: .capture(.transform(
       CaptureTransform(resultType: NewCapture.self) {
-        transform($0) as Any?
+        try transform($0) as Any?
       },
       component.regex.root)))
   }
@@ -4036,13 +3557,13 @@ extension TryCapture {
     public init<R: RegexComponent, W, C0, C1, C2, C3, C4, C5, C6, C7, C8, NewCapture>(
     _ component: R,
     as reference: Reference<NewCapture>,
-    transform: @escaping (Substring) -> NewCapture?
+    transform: @escaping (Substring) throws -> NewCapture?
   ) where Output == (Substring, NewCapture, C0, C1, C2, C3, C4, C5, C6, C7, C8), R.Output == (W, C0, C1, C2, C3, C4, C5, C6, C7, C8) {
     self.init(node: .capture(
       reference: reference.id,
       .transform(
         CaptureTransform(resultType: NewCapture.self) {
-          transform($0) as Any?
+          try transform($0) as Any?
         },
         component.regex.root)))
   }
@@ -4066,33 +3587,6 @@ extension Capture {
       component().regex.root))
   }
 
-    public init<R: RegexComponent, W, C0, C1, C2, C3, C4, C5, C6, C7, C8, NewCapture>(
-    @RegexComponentBuilder _ component: () -> R,
-    transform: @escaping (Substring) -> NewCapture
-  ) where Output == (Substring, NewCapture, C0, C1, C2, C3, C4, C5, C6, C7, C8), R.Output == (W, C0, C1, C2, C3, C4, C5, C6, C7, C8) {
-    self.init(node: .capture(.transform(
-      CaptureTransform(resultType: NewCapture.self) {
-        transform($0) as Any
-      },
-      component().regex.root)))
-  }
-
-    public init<R: RegexComponent, W, C0, C1, C2, C3, C4, C5, C6, C7, C8, NewCapture>(
-    as reference: Reference<NewCapture>,
-    @RegexComponentBuilder _ component: () -> R,
-    transform: @escaping (Substring) -> NewCapture
-  ) where Output == (Substring, NewCapture, C0, C1, C2, C3, C4, C5, C6, C7, C8), R.Output == (W, C0, C1, C2, C3, C4, C5, C6, C7, C8) {
-    self.init(node: .capture(
-      reference: reference.id,
-      .transform(
-        CaptureTransform(resultType: NewCapture.self) {
-          transform($0) as Any
-        },
-        component().regex.root)))
-  }
-}
-
-extension TryCapture {
     public init<R: RegexComponent, W, C0, C1, C2, C3, C4, C5, C6, C7, C8, NewCapture>(
     @RegexComponentBuilder _ component: () -> R,
     transform: @escaping (Substring) throws -> NewCapture
@@ -4117,14 +3611,16 @@ extension TryCapture {
         },
         component().regex.root)))
   }
+}
 
+extension TryCapture {
     public init<R: RegexComponent, W, C0, C1, C2, C3, C4, C5, C6, C7, C8, NewCapture>(
     @RegexComponentBuilder _ component: () -> R,
-    transform: @escaping (Substring) -> NewCapture?
+    transform: @escaping (Substring) throws -> NewCapture?
   ) where Output == (Substring, NewCapture, C0, C1, C2, C3, C4, C5, C6, C7, C8), R.Output == (W, C0, C1, C2, C3, C4, C5, C6, C7, C8) {
     self.init(node: .capture(.transform(
       CaptureTransform(resultType: NewCapture.self) {
-        transform($0) as Any?
+        try transform($0) as Any?
       },
       component().regex.root)))
   }
@@ -4132,13 +3628,13 @@ extension TryCapture {
     public init<R: RegexComponent, W, C0, C1, C2, C3, C4, C5, C6, C7, C8, NewCapture>(
     as reference: Reference<NewCapture>,
     @RegexComponentBuilder _ component: () -> R,
-    transform: @escaping (Substring) -> NewCapture?
+    transform: @escaping (Substring) throws -> NewCapture?
   ) where Output == (Substring, NewCapture, C0, C1, C2, C3, C4, C5, C6, C7, C8), R.Output == (W, C0, C1, C2, C3, C4, C5, C6, C7, C8) {
     self.init(node: .capture(
       reference: reference.id,
       .transform(
         CaptureTransform(resultType: NewCapture.self) {
-          transform($0) as Any?
+          try transform($0) as Any?
         },
         component().regex.root)))
   }
@@ -4159,33 +3655,6 @@ extension Capture {
     self.init(node: .capture(reference: reference.id, component.regex.root))
   }
 
-    public init<R: RegexComponent, W, C0, C1, C2, C3, C4, C5, C6, C7, C8, C9, NewCapture>(
-    _ component: R,
-    transform: @escaping (Substring) -> NewCapture
-  ) where Output == (Substring, NewCapture, C0, C1, C2, C3, C4, C5, C6, C7, C8, C9), R.Output == (W, C0, C1, C2, C3, C4, C5, C6, C7, C8, C9) {
-    self.init(node: .capture(.transform(
-      CaptureTransform(resultType: NewCapture.self) {
-        transform($0) as Any
-      },
-      component.regex.root)))
-  }
-
-    public init<R: RegexComponent, W, C0, C1, C2, C3, C4, C5, C6, C7, C8, C9, NewCapture>(
-    _ component: R,
-    as reference: Reference<NewCapture>,
-    transform: @escaping (Substring) -> NewCapture
-  ) where Output == (Substring, NewCapture, C0, C1, C2, C3, C4, C5, C6, C7, C8, C9), R.Output == (W, C0, C1, C2, C3, C4, C5, C6, C7, C8, C9) {
-    self.init(node: .capture(
-      reference: reference.id,
-      .transform(
-        CaptureTransform(resultType: NewCapture.self) {
-          transform($0) as Any
-        },
-        component.regex.root)))
-  }
-}
-
-extension TryCapture {
     public init<R: RegexComponent, W, C0, C1, C2, C3, C4, C5, C6, C7, C8, C9, NewCapture>(
     _ component: R,
     transform: @escaping (Substring) throws -> NewCapture
@@ -4210,14 +3679,16 @@ extension TryCapture {
         },
         component.regex.root)))
   }
+}
 
+extension TryCapture {
     public init<R: RegexComponent, W, C0, C1, C2, C3, C4, C5, C6, C7, C8, C9, NewCapture>(
     _ component: R,
-    transform: @escaping (Substring) -> NewCapture?
+    transform: @escaping (Substring) throws -> NewCapture?
   ) where Output == (Substring, NewCapture, C0, C1, C2, C3, C4, C5, C6, C7, C8, C9), R.Output == (W, C0, C1, C2, C3, C4, C5, C6, C7, C8, C9) {
     self.init(node: .capture(.transform(
       CaptureTransform(resultType: NewCapture.self) {
-        transform($0) as Any?
+        try transform($0) as Any?
       },
       component.regex.root)))
   }
@@ -4225,13 +3696,13 @@ extension TryCapture {
     public init<R: RegexComponent, W, C0, C1, C2, C3, C4, C5, C6, C7, C8, C9, NewCapture>(
     _ component: R,
     as reference: Reference<NewCapture>,
-    transform: @escaping (Substring) -> NewCapture?
+    transform: @escaping (Substring) throws -> NewCapture?
   ) where Output == (Substring, NewCapture, C0, C1, C2, C3, C4, C5, C6, C7, C8, C9), R.Output == (W, C0, C1, C2, C3, C4, C5, C6, C7, C8, C9) {
     self.init(node: .capture(
       reference: reference.id,
       .transform(
         CaptureTransform(resultType: NewCapture.self) {
-          transform($0) as Any?
+          try transform($0) as Any?
         },
         component.regex.root)))
   }
@@ -4255,33 +3726,6 @@ extension Capture {
       component().regex.root))
   }
 
-    public init<R: RegexComponent, W, C0, C1, C2, C3, C4, C5, C6, C7, C8, C9, NewCapture>(
-    @RegexComponentBuilder _ component: () -> R,
-    transform: @escaping (Substring) -> NewCapture
-  ) where Output == (Substring, NewCapture, C0, C1, C2, C3, C4, C5, C6, C7, C8, C9), R.Output == (W, C0, C1, C2, C3, C4, C5, C6, C7, C8, C9) {
-    self.init(node: .capture(.transform(
-      CaptureTransform(resultType: NewCapture.self) {
-        transform($0) as Any
-      },
-      component().regex.root)))
-  }
-
-    public init<R: RegexComponent, W, C0, C1, C2, C3, C4, C5, C6, C7, C8, C9, NewCapture>(
-    as reference: Reference<NewCapture>,
-    @RegexComponentBuilder _ component: () -> R,
-    transform: @escaping (Substring) -> NewCapture
-  ) where Output == (Substring, NewCapture, C0, C1, C2, C3, C4, C5, C6, C7, C8, C9), R.Output == (W, C0, C1, C2, C3, C4, C5, C6, C7, C8, C9) {
-    self.init(node: .capture(
-      reference: reference.id,
-      .transform(
-        CaptureTransform(resultType: NewCapture.self) {
-          transform($0) as Any
-        },
-        component().regex.root)))
-  }
-}
-
-extension TryCapture {
     public init<R: RegexComponent, W, C0, C1, C2, C3, C4, C5, C6, C7, C8, C9, NewCapture>(
     @RegexComponentBuilder _ component: () -> R,
     transform: @escaping (Substring) throws -> NewCapture
@@ -4306,14 +3750,16 @@ extension TryCapture {
         },
         component().regex.root)))
   }
+}
 
+extension TryCapture {
     public init<R: RegexComponent, W, C0, C1, C2, C3, C4, C5, C6, C7, C8, C9, NewCapture>(
     @RegexComponentBuilder _ component: () -> R,
-    transform: @escaping (Substring) -> NewCapture?
+    transform: @escaping (Substring) throws -> NewCapture?
   ) where Output == (Substring, NewCapture, C0, C1, C2, C3, C4, C5, C6, C7, C8, C9), R.Output == (W, C0, C1, C2, C3, C4, C5, C6, C7, C8, C9) {
     self.init(node: .capture(.transform(
       CaptureTransform(resultType: NewCapture.self) {
-        transform($0) as Any?
+        try transform($0) as Any?
       },
       component().regex.root)))
   }
@@ -4321,13 +3767,13 @@ extension TryCapture {
     public init<R: RegexComponent, W, C0, C1, C2, C3, C4, C5, C6, C7, C8, C9, NewCapture>(
     as reference: Reference<NewCapture>,
     @RegexComponentBuilder _ component: () -> R,
-    transform: @escaping (Substring) -> NewCapture?
+    transform: @escaping (Substring) throws -> NewCapture?
   ) where Output == (Substring, NewCapture, C0, C1, C2, C3, C4, C5, C6, C7, C8, C9), R.Output == (W, C0, C1, C2, C3, C4, C5, C6, C7, C8, C9) {
     self.init(node: .capture(
       reference: reference.id,
       .transform(
         CaptureTransform(resultType: NewCapture.self) {
-          transform($0) as Any?
+          try transform($0) as Any?
         },
         component().regex.root)))
   }
diff --git a/Sources/VariadicsGenerator/VariadicsGenerator.swift b/Sources/VariadicsGenerator/VariadicsGenerator.swift
index dbeff818c..5fbd2bf2d 100644
--- a/Sources/VariadicsGenerator/VariadicsGenerator.swift
+++ b/Sources/VariadicsGenerator/VariadicsGenerator.swift
@@ -615,35 +615,6 @@ struct VariadicsGenerator: ParsableCommand {
           self.init(node: .capture(reference: reference.id, component.regex.root))
         }
 
-        \(disfavored)\
-        public init<\(genericParams), NewCapture>(
-          _ component: R,
-          transform: @escaping (Substring) -> NewCapture
-        ) \(whereClauseTransformed) {
-          self.init(node: .capture(.transform(
-            CaptureTransform(resultType: NewCapture.self) {
-              transform($0) as Any
-            },
-            component.regex.root)))
-        }
-
-        \(disfavored)\
-        public init<\(genericParams), NewCapture>(
-          _ component: R,
-          as reference: Reference<NewCapture>,
-          transform: @escaping (Substring) -> NewCapture
-        ) \(whereClauseTransformed) {
-          self.init(node: .capture(
-            reference: reference.id,
-            .transform(
-              CaptureTransform(resultType: NewCapture.self) {
-                transform($0) as Any
-              },
-              component.regex.root)))
-        }
-      }
-
-      extension TryCapture {
         \(disfavored)\
         public init<\(genericParams), NewCapture>(
           _ component: R,
@@ -670,15 +641,17 @@ struct VariadicsGenerator: ParsableCommand {
               },
               component.regex.root)))
         }
+      }
 
+      extension TryCapture {
         \(disfavored)\
         public init<\(genericParams), NewCapture>(
           _ component: R,
-          transform: @escaping (Substring) -> NewCapture?
+          transform: @escaping (Substring) throws -> NewCapture?
         ) \(whereClauseTransformed) {
           self.init(node: .capture(.transform(
             CaptureTransform(resultType: NewCapture.self) {
-              transform($0) as Any?
+              try transform($0) as Any?
             },
             component.regex.root)))
         }
@@ -687,13 +660,13 @@ struct VariadicsGenerator: ParsableCommand {
         public init<\(genericParams), NewCapture>(
           _ component: R,
           as reference: Reference<NewCapture>,
-          transform: @escaping (Substring) -> NewCapture?
+          transform: @escaping (Substring) throws -> NewCapture?
         ) \(whereClauseTransformed) {
           self.init(node: .capture(
             reference: reference.id,
             .transform(
               CaptureTransform(resultType: NewCapture.self) {
-                transform($0) as Any?
+                try transform($0) as Any?
               },
               component.regex.root)))
         }
@@ -719,35 +692,6 @@ struct VariadicsGenerator: ParsableCommand {
             component().regex.root))
         }
 
-        \(disfavored)\
-        public init<\(genericParams), NewCapture>(
-          @\(concatBuilderName) _ component: () -> R,
-          transform: @escaping (Substring) -> NewCapture
-        ) \(whereClauseTransformed) {
-          self.init(node: .capture(.transform(
-            CaptureTransform(resultType: NewCapture.self) {
-              transform($0) as Any
-            },
-            component().regex.root)))
-        }
-
-        \(disfavored)\
-        public init<\(genericParams), NewCapture>(
-          as reference: Reference<NewCapture>,
-          @\(concatBuilderName) _ component: () -> R,
-          transform: @escaping (Substring) -> NewCapture
-        ) \(whereClauseTransformed) {
-          self.init(node: .capture(
-            reference: reference.id,
-            .transform(
-              CaptureTransform(resultType: NewCapture.self) {
-                transform($0) as Any
-              },
-              component().regex.root)))
-        }
-      }
-
-      extension TryCapture {
         \(disfavored)\
         public init<\(genericParams), NewCapture>(
           @\(concatBuilderName) _ component: () -> R,
@@ -774,15 +718,17 @@ struct VariadicsGenerator: ParsableCommand {
               },
               component().regex.root)))
         }
+      }
 
+      extension TryCapture {
         \(disfavored)\
         public init<\(genericParams), NewCapture>(
           @\(concatBuilderName) _ component: () -> R,
-          transform: @escaping (Substring) -> NewCapture?
+          transform: @escaping (Substring) throws -> NewCapture?
         ) \(whereClauseTransformed) {
           self.init(node: .capture(.transform(
             CaptureTransform(resultType: NewCapture.self) {
-              transform($0) as Any?
+              try transform($0) as Any?
             },
             component().regex.root)))
         }
@@ -791,13 +737,13 @@ struct VariadicsGenerator: ParsableCommand {
         public init<\(genericParams), NewCapture>(
           as reference: Reference<NewCapture>,
           @\(concatBuilderName) _ component: () -> R,
-          transform: @escaping (Substring) -> NewCapture?
+          transform: @escaping (Substring) throws -> NewCapture?
         ) \(whereClauseTransformed) {
           self.init(node: .capture(
             reference: reference.id,
             .transform(
               CaptureTransform(resultType: NewCapture.self) {
-                transform($0) as Any?
+                try transform($0) as Any?
               },
               component().regex.root)))
         }
diff --git a/Sources/_RegexParser/Regex/AST/AST.swift b/Sources/_RegexParser/Regex/AST/AST.swift
index ba37b6d62..409d5a7ee 100644
--- a/Sources/_RegexParser/Regex/AST/AST.swift
+++ b/Sources/_RegexParser/Regex/AST/AST.swift
@@ -304,78 +304,3 @@ extension AST {
     }
   }
 }
-
-// FIXME: Get this out of here
-public struct CaptureTransform: Equatable, Hashable, CustomStringConvertible {
-  public enum Closure {
-    case nonfailable((Substring) -> Any)
-    case failable((Substring) -> Any?)
-    case throwing((Substring) throws -> Any)
-  }
-  public let resultType: Any.Type
-  public let closure: Closure
-
-  public init(resultType: Any.Type, closure: Closure) {
-    self.resultType = resultType
-    self.closure = closure
-  }
-
-  public init(
-    resultType: Any.Type,
-    _ closure: @escaping (Substring) -> Any
-  ) {
-    self.init(resultType: resultType, closure: .nonfailable(closure))
-  }
-
-  public init(
-    resultType: Any.Type,
-    _ closure: @escaping (Substring) -> Any?
-  ) {
-    self.init(resultType: resultType, closure: .failable(closure))
-  }
-
-  public init(
-    resultType: Any.Type,
-    _ closure: @escaping (Substring) throws -> Any
-  ) {
-    self.init(resultType: resultType, closure: .throwing(closure))
-  }
-
-  public func callAsFunction(_ input: Substring) -> Any? {
-    switch closure {
-    case .nonfailable(let closure):
-      let result = closure(input)
-      assert(type(of: result) == resultType)
-      return result
-    case .failable(let closure):
-      guard let result = closure(input) else {
-        return nil
-      }
-      assert(type(of: result) == resultType)
-      return result
-    case .throwing(let closure):
-      do {
-        let result = try closure(input)
-        assert(type(of: result) == resultType)
-        return result
-      } catch {
-        return nil
-      }
-    }
-  }
-
-  public static func == (lhs: CaptureTransform, rhs: CaptureTransform) -> Bool {
-    unsafeBitCast(lhs.closure, to: (Int, Int).self) ==
-      unsafeBitCast(rhs.closure, to: (Int, Int).self)
-  }
-
-  public func hash(into hasher: inout Hasher) {
-    let (fn, ctx) = unsafeBitCast(closure, to: (Int, Int).self)
-    hasher.combine(fn)
-    hasher.combine(ctx)
-  }
-
-  public var description: String {
-    "<transform result_type=\(resultType)>"
-  }
-}
diff --git a/Sources/_StringProcessing/ByteCodeGen.swift b/Sources/_StringProcessing/ByteCodeGen.swift
index ed84fadbd..70233cf4f 100644
--- a/Sources/_StringProcessing/ByteCodeGen.swift
+++ b/Sources/_StringProcessing/ByteCodeGen.swift
@@ -317,7 +317,7 @@ extension Compiler.ByteCodeGen {
   ) throws {
     let transform = builder.makeTransformFunction {
       input, range in
-      t(input[range])
+      try t(input[range])
     }
     builder.buildBeginCapture(cap)
     try emitNode(child)
diff --git a/Sources/_StringProcessing/Engine/Consume.swift b/Sources/_StringProcessing/Engine/Consume.swift
index 4e00a34b4..bc60ba260 100644
--- a/Sources/_StringProcessing/Engine/Consume.swift
+++ b/Sources/_StringProcessing/Engine/Consume.swift
@@ -25,6 +25,7 @@ extension Engine {
 }
 
 extension Processor where Input == String {
+  // TODO: Should we throw here?
   mutating func consume() -> Input.Index? {
     while true {
       switch self.state {
diff --git a/Sources/_StringProcessing/Engine/MEProgram.swift b/Sources/_StringProcessing/Engine/MEProgram.swift
index a31134cc9..ecd67d4ba 100644
--- a/Sources/_StringProcessing/Engine/MEProgram.swift
+++ b/Sources/_StringProcessing/Engine/MEProgram.swift
@@ -14,11 +14,11 @@ import _RegexParser
 struct MEProgram<Input: Collection> where Input.Element: Equatable {
   typealias ConsumeFunction = (Input, Range<Input.Index>) -> Input.Index?
   typealias AssertionFunction =
-    (Input, Input.Index, Range<Input.Index>) -> Bool
+    (Input, Input.Index, Range<Input.Index>) throws -> Bool
   typealias TransformFunction =
-    (Input, Range<Input.Index>) -> Any?
+    (Input, Range<Input.Index>) throws -> Any?
   typealias MatcherFunction =
-    (Input, Input.Index, Range<Input.Index>) -> (Input.Index, Any)?
+    (Input, Input.Index, Range<Input.Index>) throws -> (Input.Index, Any)?
 
   var instructions: InstructionList<Instruction>
 
diff --git a/Sources/_StringProcessing/Engine/Processor.swift b/Sources/_StringProcessing/Engine/Processor.swift
index 343b02c92..8f777ad33 100644
--- a/Sources/_StringProcessing/Engine/Processor.swift
+++ b/Sources/_StringProcessing/Engine/Processor.swift
@@ -51,6 +51,8 @@ struct Processor<
 
   var state: State = .inProgress
 
+  var failureReason: Error? = nil
+
   var isTracingEnabled: Bool
 
   var storedCaptures: Array<_StoredCapture>
@@ -181,6 +183,13 @@ extension Processor {
     registers.ints = intRegisters
   }
 
+  mutating func abort(_ e: Error? = nil) {
+    if let e = e {
+      self.failureReason = e
+    }
+    self.state = .fail
+  }
+
   mutating func tryAccept() {
     switch (currentPosition, matchMode) {
     // When reaching the end of the match bounds or when we are only doing a
@@ -355,8 +364,13 @@ extension Processor {
     case .assertBy:
       let reg = payload.assertion
       let assertion = registers[reg]
-      guard assertion(input, currentPosition, bounds) else {
-        signalFailure()
+      do {
+        guard try assertion(input, currentPosition, bounds) else {
+          signalFailure()
+          return
+        }
+      } catch {
+        abort(error)
         return
       }
       controller.step()
@@ -364,15 +378,20 @@ extension Processor {
     case .matchBy:
       let (matcherReg, valReg) = payload.pairedMatcherValue
       let matcher = registers[matcherReg]
-      guard let (nextIdx, val) = matcher(
-        input, currentPosition, bounds
-      ) else {
-        signalFailure()
+      do {
+        guard let (nextIdx, val) = try matcher(
+          input, currentPosition, bounds
+        ) else {
+          signalFailure()
+          return
+        }
+        registers[valReg] = val
+        advance(to: nextIdx)
+        controller.step()
+      } catch {
+        abort(error)
         return
       }
-      registers[valReg] = val
-      advance(to: nextIdx)
-      controller.step()
 
     case .print:
       // TODO: Debug stream
@@ -431,14 +450,18 @@ extension Processor {
         fatalError(
           "Unreachable: transforming without a capture")
       }
-      // FIXME: Pass input or the slice?
-      guard let value = transform(input, range) else {
-        signalFailure()
+      do {
+        // FIXME: Pass input or the slice?
+        guard let value = try transform(input, range) else {
+          signalFailure()
+          return
+        }
+        storedCaptures[capNum].registerValue(value)
+        controller.step()
+      } catch {
+        abort(error)
         return
       }
-      storedCaptures[capNum].registerValue(value)
-
-      controller.step()
 
     case .captureValue:
       let (val, cap) = payload.pairedValueCapture
diff --git a/Sources/_StringProcessing/Executor.swift b/Sources/_StringProcessing/Executor.swift
index 148ddf468..563e90970 100644
--- a/Sources/_StringProcessing/Executor.swift
+++ b/Sources/_StringProcessing/Executor.swift
@@ -28,6 +28,9 @@ struct Executor {
       input: input, bounds: inputRange, matchMode: mode)
 
     guard let endIdx = cpu.consume() else {
+      if let e = cpu.failureReason {
+        throw e
+      }
       return nil
     }
 
diff --git a/Sources/_StringProcessing/Regex/DSLTree.swift b/Sources/_StringProcessing/Regex/DSLTree.swift
index 59ebd38af..f37505cb4 100644
--- a/Sources/_StringProcessing/Regex/DSLTree.swift
+++ b/Sources/_StringProcessing/Regex/DSLTree.swift
@@ -164,14 +164,14 @@ extension DSLTree {
 @_spi(RegexBuilder)
 public typealias _ConsumerInterface = (
   String, Range<String.Index>
-) -> String.Index?
+) throws -> String.Index?
 
 // Type producing consume
 // TODO: better name
 @_spi(RegexBuilder)
 public typealias _MatcherInterface = (
   String, String.Index, Range<String.Index>
-) -> (String.Index, Any)?
+) throws -> (String.Index, Any)?
 
 // Character-set (post grapheme segmentation)
 @_spi(RegexBuilder)
@@ -384,3 +384,62 @@ public struct ReferenceID: Hashable, Equatable {
     Self.counter += 1
   }
 }
+
+@_spi(RegexBuilder)
+public struct CaptureTransform: Hashable, CustomStringConvertible {
+  public enum Closure {
+    case failable((Substring) throws -> Any?)
+    case nonfailable((Substring) throws -> Any)
+  }
+  public let resultType: Any.Type
+  public let closure: Closure
+
+  public init(resultType: Any.Type, closure: Closure) {
+    self.resultType = resultType
+    self.closure = closure
+  }
+
+  public init(
+    resultType: Any.Type,
+    _ closure: @escaping (Substring) throws -> Any
+  ) {
+    self.init(resultType: resultType, closure: .nonfailable(closure))
+  }
+
+  public init(
+    resultType: Any.Type,
+    _ closure: @escaping (Substring) throws -> Any?
+  ) {
+    self.init(resultType: resultType, closure: .failable(closure))
+  }
+
+  public func callAsFunction(_ input: Substring) throws -> Any? {
+    switch closure {
+    case .nonfailable(let closure):
+      let result = try closure(input)
+      assert(type(of: result) == resultType)
+      return result
+    case .failable(let closure):
+      guard let result = try closure(input) else {
+        return nil
+      }
+      assert(type(of: result) == resultType)
+      return result
+    }
+  }
+
+  public static func == (lhs: CaptureTransform, rhs: CaptureTransform) -> Bool {
+    unsafeBitCast(lhs.closure, to: (Int, Int).self) ==
+      unsafeBitCast(rhs.closure, to: (Int, Int).self)
+  }
+
+  public func hash(into hasher: inout Hasher) {
+    let (fn, ctx) = unsafeBitCast(closure, to: (Int, Int).self)
+    hasher.combine(fn)
+    hasher.combine(ctx)
+  }
+
+  public var description: String {
+    "<transform result_type=\(resultType)>"
+  }
+}
diff --git a/Sources/_StringProcessing/Regex/Match.swift b/Sources/_StringProcessing/Regex/Match.swift
index 45d33f03e..5c846c0fd 100644
--- a/Sources/_StringProcessing/Regex/Match.swift
+++ b/Sources/_StringProcessing/Regex/Match.swift
@@ -130,7 +130,7 @@ extension RegexComponent {
     mode: MatchMode = .wholeString
   ) throws -> Regex<Output>.Match? {
     let executor = Executor(program: regex.program.loweredProgram)
-      return try executor.match(input, in: inputRange, mode)
+    return try executor.match(input, in: inputRange, mode)
   }
 
   func _firstMatch(
diff --git a/Tests/RegexBuilderTests/CustomTests.swift b/Tests/RegexBuilderTests/CustomTests.swift
index 19c4a3896..79ebc2693 100644
--- a/Tests/RegexBuilderTests/CustomTests.swift
+++ b/Tests/RegexBuilderTests/CustomTests.swift
@@ -138,4 +138,89 @@ class CustomRegexComponentTests: XCTestCase {
     XCTAssertEqual(res4.output.0, "123")
     XCTAssertEqual(res4.output.1, 3)
   }
+
+  func testRegexAbort() {
+
+    enum Radix: Hashable {
+      case dot
+      case comma
+    }
+    struct Abort: Error, Hashable {}
+
+    let hexRegex = Regex {
+      Capture { OneOrMore(.hexDigit) }
+      TryCapture { CharacterClass.any } transform: { c -> Radix? in
+        switch c {
+        case ".": return Radix.dot
+        case ",": return Radix.comma
+        case "❗️":
+          // Malicious! Toxic levels of emphasis detected.
+          throw Abort()
+        default:
+          // Not a radix
+          return nil
+        }
+      }
+      Capture { OneOrMore(.hexDigit) }
+    }
+    // hexRegex: Regex<(Substring, Substring, Radix?, Substring)>
+    // TODO: Why is Radix optional?
+
+    do {
+      guard let m = try hexRegex.matchWhole("123aef.345") else {
+        XCTFail()
+        return
+      }
+      XCTAssertEqual(m.0, "123aef.345")
+      XCTAssertEqual(m.1, "123aef")
+      XCTAssertEqual(m.2, .dot)
+      XCTAssertEqual(m.3, "345")
+    } catch {
+      XCTFail()
+    }
+
+    do {
+      _ = try hexRegex.matchWhole("123aef❗️345")
+      XCTFail()
+    } catch let e as Abort {
+      XCTAssertEqual(e, Abort())
+    } catch {
+      XCTFail()
+    }
+
+    struct Poison: Error, Hashable {}
+
+    let addressRegex = Regex {
+      "0x"
+      Capture(Repeat(.hexDigit, count: 8)) { hex -> Int in
+        let i = Int(hex, radix: 16)!
+        if i == 0xdeadbeef {
+          throw Poison()
+        }
+        return i
+      }
+    }
+
+    do {
+      guard let m = try addressRegex.matchWhole("0x1234567f") else {
+        XCTFail()
+        return
+      }
+      XCTAssertEqual(m.0, "0x1234567f")
+      XCTAssertEqual(m.1, 0x1234567f)
+    } catch {
+      XCTFail()
+    }
+
+    do {
+      _ = try addressRegex.matchWhole("0xdeadbeef")
+      XCTFail()
+    } catch let e as Poison {
+      XCTAssertEqual(e, Poison())
+    } catch {
+      XCTFail()
+    }
+
+
+  }
 }