6.0 candidate

typed/txexpr/main.rkt

@@ -3,8 +3,9 @@
 (require racket/match racket/string racket/list racket/bool "core-predicates.rkt")
 (provide (all-defined-out) (all-from-out "core-predicates.rkt"))
 (require typed/sugar/debug)
+
 (define/typed (validate-txexpr-attrs x #:context [txexpr-context #f])
-  (Txexpr-Attrs #:context Any  -> Txexpr-Attrs)
+  (Txexpr-Attrs [#:context Any]  -> Txexpr-Attrs)
   (define/typed (make-reason)
     (-> String)
     (if (not (list? x)) 
@@ -21,7 +22,7 @@
 
 
 (define/typed (validate-txexpr-element x #:context [txexpr-context #f])
-  (Txexpr-Element #:context Any -> Txexpr-Element)
+  (Txexpr-Element [#:context Any] -> Txexpr-Element)
   (cond
     [(or (string? x) (txexpr? x) (symbol? x)
          (valid-char? x) (cdata? x)) x]
@@ -44,12 +45,18 @@
     [else (error 'validate-txexpr (format "~v is not a list starting with a symbol" x))]))
 
 
-(define/typed (make-txexpr tag [attrs null] [elements null])
-  (Symbol Txexpr-Attrs (Listof Txexpr-Element) -> Txexpr)
+(define/typed make-txexpr
+  (case-> (Symbol -> Txexpr)
+          (Symbol Txexpr-Attrs -> Txexpr)
+          (Symbol Txexpr-Attrs (Listof Txexpr-Element) -> Txexpr))
+  (case-lambda
+    [(tag) (make-txexpr tag null null)]
+    [(tag attrs) (make-txexpr tag attrs null)]
+    [(tag attrs elements)
      (define result (cons tag (append (if (empty? attrs) empty (list attrs)) elements)))
      (if (txexpr? result)
          result
-      (error 'make-txexpr "This can't happen")))
+         (error 'make-txexpr "This can't happen"))]))
 
 
 (define/typed (txexpr->values x)
@@ -205,8 +212,12 @@
 
 ;; function to split tag out of txexpr
 (define deleted-signal (gensym))
-(define/typed (splitf-txexpr tx pred [proc (λ:([x : Xexpr]) deleted-signal)])
-  (Txexpr (Xexpr -> Boolean) (Xexpr -> Xexpr) -> (values Txexpr Txexpr-Elements))
+(define/typed splitf-txexpr
+  (case-> (Txexpr (Xexpr -> Boolean) -> (values Txexpr Txexpr-Elements))
+          (Txexpr (Xexpr -> Boolean) (Xexpr -> Xexpr) -> (values Txexpr Txexpr-Elements)))
+  (case-lambda
+    [(tx pred) (splitf-txexpr tx pred (λ:([x : Xexpr]) deleted-signal))]
+    [(tx pred proc)
      (define: matches : Txexpr-Elements null)
      (define/typed (do-extraction x)
        (Xexpr -> Xexpr)
@@ -217,10 +228,10 @@
          [(txexpr? x) (let-values([(tag attr elements) (txexpr->values x)]) 
                         (make-txexpr tag attr (filter (λ:([e : Xexpr]) (not (equal? e deleted-signal))) (map do-extraction elements))))]
          [else x]))
-  (define tx-extracted (do-extraction tx)) ;; do this first to fill matches
+     (define: tx-extracted : Xexpr (do-extraction tx)) ;; do this first to fill matches
      (values (if (txexpr? tx-extracted)
                  tx-extracted
-              (error 'splitf-txexpr "Can't get here")) (reverse matches)))
+                 (error 'splitf-txexpr "Can't get here")) (reverse matches))]))
 
 
 (define/typed (xexpr->html x)