Added let-abort and let*-abort

graph/graph/_examples_cond-abort.rkt

@@ -0,0 +1,13 @@
+#lang typed/racket
+
+(require "cond-abort.rkt")
+
+(match-abort '(1 (a b) 3)
+  [(list x y z)
+   (let-abort ([new-x x]
+               [new-y (match-abort y
+                        [(list n p) (list 'A n p)]
+                        [(list q r s) (list 'B q r s)])]
+               [new-z z])
+              (list new-x new-y new-z))])
+

graph/graph/cond-abort.rkt

@@ -1,7 +1,9 @@
 #lang typed/racket
 
 (provide cond-abort
-         match-abort)
+         match-abort
+         let-abort
+         let*-abort)
 
 (define-syntax (cond-abort orig-stx)
   (let rec ([stx orig-stx])
@@ -37,6 +39,23 @@
            [_ 'continue])]
      ...)))
 
+(define-syntax-rule (let-abort ([binding value] ...) . body)
+  (let ([binding value] ...)
+    (cond
+      [(or (eq? 'continue binding) (eq? 'break binding)) binding]
+      ...
+      [else (begin . body)])))
+
+(define-syntax (let*-abort stx)
+  (syntax-case stx ()
+    [(_ () . body)
+     #'(begin . body)]
+    [(_ ([binding0 value0] . rest) . body)
+     #'(let ([binding0 value0])
+         (if (or (eq? 'continue binding) (eq? 'break binding))
+             binding
+             (let*-abort rest . body)))]))
+
 (module* test typed/racket
   (require typed/rackunit)
   (require (submod ".."))