From f14284df60dd5693009961b536a8b63be37faadf Mon Sep 17 00:00:00 2001
From: Matthew Butterick <mb@mbtype.com>
Date: Tue, 19 May 2015 19:05:32 -0700
Subject: [PATCH] resume in typed tests

---
 info.rkt                         |   2 +-
 txexpr/core-predicates.rkt       |   3 +
 txexpr/main.rkt                  | 289 +------------------------------
 typed/txexpr/core-predicates.rkt |  33 ++--
 typed/txexpr/main.rkt            | 105 +++++------
 typed/txexpr/tests.rkt           | 159 +++++++++++++++++
 6 files changed, 240 insertions(+), 351 deletions(-)
 create mode 100644 txexpr/core-predicates.rkt
 create mode 100644 typed/txexpr/tests.rkt

diff --git a/info.rkt b/info.rkt
index 350e8f9..70f980f 100644
--- a/info.rkt
+++ b/info.rkt
@@ -1,4 +1,4 @@
 #lang info
 (define collection 'multi)
-(define deps '("base"))
+(define deps '("base" "sugar"))
 (define build-deps '("scribble-lib" "racket-doc"))
diff --git a/txexpr/core-predicates.rkt b/txexpr/core-predicates.rkt
new file mode 100644
index 0000000..aa49d61
--- /dev/null
+++ b/txexpr/core-predicates.rkt
@@ -0,0 +1,3 @@
+#lang racket/base
+
+;; zilch
\ No newline at end of file
diff --git a/txexpr/main.rkt b/txexpr/main.rkt
index 8c2b0a6..737559e 100644
--- a/txexpr/main.rkt
+++ b/txexpr/main.rkt
@@ -1,29 +1,10 @@
 #lang racket/base
-(require (for-syntax racket/base))
-(require racket/match xml racket/string racket/list racket/bool)
+(require sugar/include sugar/define xml)
 
-(module+ safe (require racket/contract))
-
-(define-syntax (define+provide+safe stx)
-  (syntax-case stx ()
-    [(_ (proc arg ... . rest-arg) contract body ...)
-     #'(define+provide+safe proc contract
-         (λ(arg ... . rest-arg) body ...))]
-    [(_ name contract body ...)
-     #'(begin
-         (define name body ...)
-         (provide name)
-         (module+ safe 
-           (provide (contract-out [name contract]))))]))
-
-(define+provide+safe (txexpr-tag? x)
-  (any/c . -> . boolean?)
-  (symbol? x)) 
-
-(define+provide+safe (txexpr-tags? x)
+(define+provide+safe (txexpr? x)
   (any/c . -> . boolean?)
-  (and (list? x) (andmap txexpr-tag? x)))
-
+  (with-handlers ([exn:fail? (λ(exn) #f)])
+    (and (validate-txexpr x) #t)))
 
 (define+provide+safe (txexpr-attr? x)
   (any/c . -> . boolean?)
@@ -31,264 +12,4 @@
     [(list (? symbol?) (? string?)) #t]
     [else #f]))
 
-
-(define (validate-txexpr-attrs x #:context [txexpr-context #f])
-  ; ((any/c) (#:context (or/c #f txexpr?)) . ->* . txexpr-attrs?)
-  (define (make-reason) 
-    (if (not (list? x)) 
-        (format "because ~v is not a list" x)
-        (let ([bad-attrs (filter (λ(i) (not (txexpr-attr? i))) x)])
-          (format "because ~a ~a" (string-join (map (λ(ba) (format "~v" ba)) bad-attrs) " and ") (if (> (length bad-attrs) 1)
-                                                                                                     "are not valid attributes"
-                                                                                                     "is not in the form '(symbol \"string\")")))))
-  (match x
-    [(list (? txexpr-attr?) ...) x]
-    [else [else (error (string-append "validate-txexpr-attrs: "
-                                      (if txexpr-context (format "in ~v, " txexpr-context) "")
-                                      (format "~v is not a valid list of attributes ~a" x (make-reason))))]]))
-
-(define+provide+safe (txexpr-attrs? x)
-  (any/c . -> . boolean?)
-  (with-handlers ([exn:fail? (λ(exn) #f)])
-    (and (validate-txexpr-attrs x) #t)))
-
-
-(define+provide+safe (txexpr-elements? x)
-  (any/c . -> . boolean?)
-  (match x
-    [(list elem ...) (andmap txexpr-element? elem)]
-    [else #f]))
-
-
-(define (validate-txexpr-element x #:context [txexpr-context #f])
-  ; ((any/c) (#:context (or/c #f txexpr?)) . ->* . txexpr-element?)
-  (cond
-    [(or (string? x) (txexpr? x) (symbol? x)
-         (valid-char? x) (cdata? x)) x]
-    [else (error (string-append "validate-txexpr-element: "
-                                (if txexpr-context (format "in ~v, " txexpr-context) "")
-                                (format "~v is not a valid element (must be txexpr, string, symbol, XML char, or cdata)" x)))]))
-
-
-(define+provide+safe (txexpr-element? x)
-  (any/c . -> . boolean?)
-  (with-handlers ([exn:fail? (λ(exn) #f)])
-    (and (validate-txexpr-element x) #t)))
-
-
-;; is it a named x-expression?
-;; todo: rewrite this recurively so errors can be pinpointed (for debugging)
-(define+provide+safe (validate-txexpr x)
-  (any/c . -> . txexpr?)
-  (define (validate-txexpr-element-with-context e) (validate-txexpr-element e #:context x))
-  (define (validate-txexpr-attrs-with-context e) (validate-txexpr-attrs e #:context x))
-  
-  (when (match x
-          [(list (? symbol?)) #t]
-          [(list (? symbol? name) (and attr-list (list (list k v ...) ...)) rest ...) 
-           (and (validate-txexpr-attrs-with-context attr-list) 
-                (andmap validate-txexpr-element-with-context rest))]
-          [(list (? symbol? name) rest ...)(andmap validate-txexpr-element-with-context rest)]
-          [else (error (format "validate-txexpr: ~v is not a list starting with a symbol" x))])
-    x))
-
-(define+provide+safe (txexpr? x)
-  (any/c . -> . boolean?)
-  (with-handlers ([exn:fail? (λ(exn) #f)])
-    (and (validate-txexpr x) #t)))
-
-
-
-(define+provide+safe (make-txexpr tag [attrs null] [elements null])
-  ;; todo?: use xexpr/c provides a nicer error message
-  ((symbol?) (txexpr-attrs? txexpr-elements?) 
-             . ->* . txexpr?)
-  (filter (compose1 not null?) `(,tag ,attrs ,@elements)))
-
-
-(define+provide+safe (txexpr->values x)
-  (txexpr? . -> . (values symbol? txexpr-attrs? txexpr-elements?))
-  (match 
-      ; txexpr may or may not have attr
-      ; if not, add null attr so that decomposition only handles one case
-      (match x
-        [(list _ (? txexpr-attrs?) _ ...) x]
-        [else `(,(car x) ,null ,@(cdr x))])
-    [(list tag attr content ...) (values tag attr content)]))
-
-
-(define+provide+safe (txexpr->list x)
-  (txexpr? . -> . list?)
-  (define-values (tag attrs content) (txexpr->values x))
-  (list tag attrs content))
-
-
-;; convenience functions to retrieve only one part of txexpr
-(define+provide+safe (get-tag x)
-  (txexpr? . -> . txexpr-tag?)
-  (car x))
-
-
-(define+provide+safe (get-attrs x)
-  (txexpr? . -> . txexpr-attrs?)
-  (define-values (tag attrs content) (txexpr->values x))
-  attrs)
-
-
-(define+provide+safe (get-elements x)
-  (txexpr? . -> . txexpr-elements?)
-  (define-values (tag attrs elements) (txexpr->values x))
-  elements)
-
-
-;; helpers. we are getting a string or symbol
-(define+provide+safe (->txexpr-attr-key x)
-  (can-be-txexpr-attr-key? . -> . txexpr-attr-key?)
-  (if (string? x) (string->symbol x) x))
-
-(define+provide+safe (->txexpr-attr-value x)
-  (can-be-txexpr-attr-value? . -> . txexpr-attr-value?)
-  (->string x))
-
-(define+provide+safe (txexpr-attr-key? x) 
-  (any/c . -> . boolean?)
-  (symbol? x))
-
-(define+provide+safe (can-be-txexpr-attr-key? x)
-  (any/c . -> . boolean?)
-  (or (symbol? x) (string? x)))
-
-(define+provide+safe (txexpr-attr-value? x) 
-  (any/c . -> . boolean?)
-  (string? x))
-
-(define (txexpr-attr-values? xs) (and (list? xs) (andmap txexpr-attr-value? xs)))
-
-(define+provide+safe (can-be-txexpr-attr-value? x) 
-  (any/c . -> . boolean?)
-  (can-be-txexpr-attr-key? x))
-
-(define (->string x) 
-  (if (symbol? x) (symbol->string x) x))
-
-(define+provide+safe (can-be-txexpr-attrs? x) 
-  (any/c . -> . boolean?)
-  (ormap (λ(test) (test x)) (list txexpr-attr? txexpr-attrs? can-be-txexpr-attr-key? can-be-txexpr-attr-value?)))
-
-(define (list-of-can-be-txexpr-attrs? xs) (and (list? xs) (andmap can-be-txexpr-attrs? xs)))
-
-(define+provide+safe (attrs->hash . items)
-  (() #:rest list-of-can-be-txexpr-attrs? . ->* . hash?)
-  ;; can be liberal with input because they're all just nested key/value pairs
-  ;; but still need this function to make sure that 'foo and "foo" are treated as the same hash key
-  (define (make-key-value-list items)
-    (if (null? items)
-        null
-        (let ([key (->txexpr-attr-key (car items))]
-              [value (->txexpr-attr-value (cadr items))]
-              [rest (cddr items)])
-          (cons (cons key value) (make-key-value-list rest)))))
-  (make-immutable-hash (make-key-value-list (flatten items))))
-
-(define+provide+safe (hash->attrs hash)
-  (hash? . -> . txexpr-attrs?)
-  (hash-map hash list))
-
-(define+provide+safe (attrs-have-key? x key)
-  ((or/c txexpr-attrs? txexpr?) can-be-txexpr-attr-key? . -> . boolean?)
-  (define attrs (if (txexpr-attrs? x) x (get-attrs x)))
-  (hash-has-key? (attrs->hash attrs) (->txexpr-attr-key key)))
-
-(define+provide+safe (attrs-equal? x1 x2)
-  ((or/c txexpr-attrs? txexpr?) (or/c txexpr-attrs? txexpr?) . -> . boolean?)
-  (define attrs-tx1 (attrs->hash (if (txexpr-attrs? x1) x1 (get-attrs x1))))
-  (define attrs-tx2 (attrs->hash (if (txexpr-attrs? x2) x2 (get-attrs x2))))
-  (and 
-   (= (length (hash-keys attrs-tx1)) (length (hash-keys attrs-tx2)))
-   (for/and ([(key value) (in-hash attrs-tx1)])
-     (equal? (hash-ref attrs-tx2 key) value))))
-
-(define+provide+safe (attr-set tx key value)
-  (txexpr? can-be-txexpr-attr-key? can-be-txexpr-attr-value? . -> . txexpr?)
-  (define new-attrs 
-    (hash->attrs (hash-set (attrs->hash (get-attrs tx)) (->txexpr-attr-key key) (->txexpr-attr-value value))))
-  (make-txexpr (get-tag tx) new-attrs (get-elements tx)))
-
-
-(define+provide+safe (attr-ref tx key)
-  (txexpr? can-be-txexpr-attr-key? . -> . txexpr-attr-value?)
-  (with-handlers ([exn:fail? (λ(e) (error (format "attr-ref: no value found for key ~v" key)))])
-    (hash-ref (attrs->hash (get-attrs tx)) key)))
-
-(define+provide+safe (attr-ref* tx key)
-  (txexpr? can-be-txexpr-attr-key? . -> . txexpr-attr-values?)
-  (filter-not false? 
-              (flatten 
-               (let loop ([tx tx])
-                 (and (txexpr? tx)
-                      (cons (and (attrs-have-key? tx key)(attr-ref tx key)) 
-                            (map loop (get-elements tx))))))))
-
-;; convert list of alternating keys & values to attr
-(define+provide+safe (merge-attrs . items)
-  (() #:rest list-of-can-be-txexpr-attrs? . ->* . txexpr-attrs?)
-  (define attrs-hash (apply attrs->hash items))
-  ;; sort needed for predictable results for unit tests
-  (define sorted-hash-keys (sort (hash-keys attrs-hash) (λ(a b) (string<? (->string a) (->string b)))))
-  `(,@(map (λ(key) (list key (hash-ref attrs-hash key))) sorted-hash-keys)))
-
-
-(define+provide+safe (remove-attrs x)
-  (txexpr? . -> . txexpr?)
-  (cond
-    [(txexpr? x) (let-values ([(tag attr elements) (txexpr->values x)])
-                   (make-txexpr tag null (remove-attrs elements)))]
-    [(txexpr-elements? x) (map remove-attrs x)]
-    [else x]))
-
-;; todo: exclude-proc will keep things out, but is there a way to keep things in?
-(define+provide+safe (map-elements/exclude proc x exclude-test)
-  (procedure? txexpr? procedure? . -> . txexpr?)
-  (cond
-    [(txexpr? x) 
-     (if (exclude-test x)
-         x
-         (let-values ([(tag attr elements) (txexpr->values x)])
-           (make-txexpr tag attr 
-                        (map (λ(x)(map-elements/exclude proc x exclude-test)) elements))))]
-    ;; externally the function only accepts txexpr,
-    ;; but internally we don't care
-    [else (proc x)]))
-
-(define+provide+safe (map-elements proc x)
-  (procedure? txexpr? . -> . txexpr?)
-  (map-elements/exclude proc x (λ(x) #f)))
-
-;; function to split tag out of txexpr
-(define+provide+safe (splitf-txexpr tx pred [proc (λ(x) null)])
-  ((txexpr? procedure?) (procedure?) . ->* . (values txexpr? txexpr-elements?))
-  (define matches null)
-  (define (do-extraction x)
-    (cond
-      [(pred x) (begin  ; store matched item and return processed value
-                  (set! matches (cons x matches))
-                  (proc x))]
-      [(txexpr? x) (let-values([(tag attr body) (txexpr->values x)]) 
-                     (make-txexpr tag attr (do-extraction body)))]
-      [(txexpr-elements? x) (filter (compose1 not null?) (map do-extraction x))]
-      [else x]))
-  (define tx-extracted (do-extraction tx)) ;; do this first to fill matches
-  (values tx-extracted (reverse matches))) 
-
-(define+provide+safe (xexpr->html x)
-  (xexpr? . -> . string?)
-  (define (->cdata x)
-    (if (cdata? x) x (cdata #f #f x)))
-  
-  (xexpr->string (let loop ([x x])
-                   (cond
-                     [(txexpr? x) (if (member (get-tag x) '(script style))
-                                      (make-txexpr (get-tag x) (get-attrs x) (map ->cdata (get-elements x)))
-                                      (make-txexpr (get-tag x) (get-attrs x) (map loop (get-elements x))))]
-                     [else x]))))
-
+(include-without-lang-line "../typed/txexpr/main.rkt")
diff --git a/typed/txexpr/core-predicates.rkt b/typed/txexpr/core-predicates.rkt
index a112006..a795930 100644
--- a/typed/txexpr/core-predicates.rkt
+++ b/typed/txexpr/core-predicates.rkt
@@ -1,10 +1,18 @@
 #lang typed/racket/base
-(require (for-syntax racket/base) racket/match)
-(provide (all-defined-out) valid-char? cdata?)
+(require (for-syntax racket/base) racket/match typed/sugar/define)
+(provide (all-defined-out))
+
+; Section 2.2 of XML 1.1
+; (XML 1.0 is slightly different and more restrictive)
+(define/typed (valid-char? i)
+  (Any -> Boolean)
+  (and (exact-nonnegative-integer? i)
+       (or (<= #x1     i #xD7FF)
+           (<= #xE000  i #xFFFD)
+           (<= #x10000 i #x10FFFF))))
 
 (require/typed
  xml
- [valid-char? (Any -> Boolean)]
  [#:struct location ([line : (Option Natural)]
                      [char : (Option Natural)]
                      [offset : Natural])]
@@ -13,7 +21,12 @@
  [#:struct (cdata source) ([string : String])]
  [#:struct comment ([text : String])]
  [#:struct (p-i source) ([target-name : Symbol]
-                         [instruction : String])])
+                         [instruction : String])]
+ [xexpr->string (Xexpr -> String)])
+(provide (all-from-out xml) cdata? xexpr->string)
+
+
+
 
 (define-type Valid-Char Natural) ;; overinclusive but that's as good as it gets
 (define-type Txexpr-Tag Symbol)
@@ -40,17 +53,9 @@
      comment
      p-i))
 
-(define-syntax (define/typed stx)
-  (syntax-case stx ()
-    [(_ (proc-name arg ... . rest-arg) type-expr body ...)
-     #'(define/typed proc-name type-expr
-         (λ(arg ... . rest-arg) body ...))]
-    [(_ proc-name type-expr body ...)
-     #'(begin
-         (: proc-name type-expr)
-         (define proc-name body ...))]))
 
 (define-predicate txexpr? Txexpr)
+(define-predicate txexpr-short? Txexpr-Short)
 (define-predicate txexpr-tag? Txexpr-Tag)
 (define-predicate txexpr-tags? (Listof Txexpr-Tag))
 (define-predicate txexpr-attr? Txexpr-Attr)
@@ -65,4 +70,4 @@
 (define-predicate can-be-txexpr-attr? (List Can-Be-Txexpr-Attr-Key Can-Be-Txexpr-Attr-Value))
 (define-type Can-Be-Txexpr-Attr (U Txexpr-Attr Txexpr-Attrs Can-Be-Txexpr-Attr-Key Can-Be-Txexpr-Attr-Value))
 (define-predicate can-be-txexpr-attrs? Can-Be-Txexpr-Attr)
-(define-predicate list-of-can-be-txexpr-attrs? (Listof Can-Be-Txexpr-Attr))
+(define-predicate list-of-can-be-txexpr-attrs? (Listof Can-Be-Txexpr-Attr))
\ No newline at end of file
diff --git a/typed/txexpr/main.rkt b/typed/txexpr/main.rkt
index ba378c5..ff16d00 100644
--- a/typed/txexpr/main.rkt
+++ b/typed/txexpr/main.rkt
@@ -1,11 +1,10 @@
 #lang typed/racket/base
-(require (for-syntax typed/racket/base))
+(require (for-syntax typed/racket/base) typed/sugar/define)
 (require racket/match racket/string racket/list racket/bool "core-predicates.rkt")
 (provide (all-defined-out) (all-from-out "core-predicates.rkt"))
 
-
 (define/typed (validate-txexpr-attrs x #:context [txexpr-context #f])
-  ((Any) (#:context Boolean) . ->* . Txexpr-Attrs)
+  ((Txexpr-Attrs) (#:context Any) . ->* . Txexpr-Attrs)
   (define/typed (make-reason)
     (-> String)
     (if (not (list? x)) 
@@ -22,10 +21,10 @@
 
 
 (define/typed (validate-txexpr-element x #:context [txexpr-context #f])
-  ((Any) (#:context Any) . ->* . Txexpr-Element)
+  ((Txexpr-Element) (#:context Any) . ->* . Txexpr-Element)
   (cond
     [(or (string? x) (txexpr? x) (symbol? x)
-         (valid-char? x) (cdata? x)) (cast x Txexpr-Element)]
+         (valid-char? x) (cdata? x)) x]
     [else (error (string-append "validate-txexpr-element: "
                                 (if txexpr-context (format "in ~v, " txexpr-context) "")
                                 (format "~v is not a valid element (must be txexpr, string, symbol, XML char, or cdata)" x)))]))
@@ -34,35 +33,30 @@
 ;; is it a named x-expression?
 ;; todo: rewrite this recurively so errors can be pinpointed (for debugging)
 (define/typed (validate-txexpr x)
-  (Any -> Txexpr)
-  (define-syntax-rule (validate-txexpr-element-with-context e) (validate-txexpr-element e #:context x))
+  (Any -> (Option Txexpr))
   (define-syntax-rule (validate-txexpr-attrs-with-context e) (validate-txexpr-attrs e #:context x))
-  (if (match x
-        [(list (? symbol?)) #t]
-        ;; todo: fix this condition
-        #;[(list (? symbol?) (and attr-list (list (list k v ...) ...)) rest ...) 
-           (and (validate-txexpr-attrs-with-context (cast attr-list Txexpr-Attrs)) 
-                (andmap (λ(e) (validate-txexpr-element-with-context e)) rest))]
-        [(list (? symbol? name) rest ...)(andmap (λ(e) (validate-txexpr-element-with-context e)) rest)]
-        [else (error 'validate-txexpr (format "~v is not a list starting with a symbol" x))])
-      (cast x Txexpr)
-      (error 'validate-txexpr "Can't reach this")))
+  (define-syntax-rule (validate-txexpr-element-with-context e) (validate-txexpr-element e #:context x))
+  (cond
+    [(txexpr-short? x) x]
+    [(txexpr? x) (and
+                  (validate-txexpr-attrs-with-context (get-attrs x))
+                  (andmap (λ([e : Txexpr-Element]) (validate-txexpr-element-with-context e)) (get-elements x)) x)]
+    [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)
-  (cast (cons tag (append (if (empty? attrs) empty (list attrs)) elements)) Txexpr))
+  (define result (cons tag (append (if (empty? attrs) empty (list attrs)) elements)))
+  (if (txexpr? result)
+      result
+      (error 'make-txexpr "This can't happen")))
 
 
 (define/typed (txexpr->values x)
   (Txexpr -> (values Txexpr-Tag Txexpr-Attrs Txexpr-Elements))
-  (match 
-      ; txexpr may or may not have attr
-      ; if not, add null attr so that decomposition only handles one case
-      (match x
-        [(list _ (? txexpr-attrs?) _ ...) x]
-        [else `(,(car x) ,null ,@(cdr x))])
-    [(list tag attr content ...) (values tag (cast attr Txexpr-Attrs) (cast content Txexpr-Elements))]))
+  (if (txexpr-short? x)
+      (values (car x) '() (cdr x))
+      (values (car x) (cadr x) (cddr x))))
 
 
 (define/typed (txexpr->list x)
@@ -113,12 +107,12 @@
                  (for/fold ([items : (Listof (U Can-Be-Txexpr-Attr-Key Can-Be-Txexpr-Attr-Value)) null])
                            ([i (in-list items-in)])
                    (cond
-                     [(txexpr-attr? i) (append i items)]
-                     [(txexpr-attrs? i) (append (append* i) items)]
+                     [(txexpr-attr? i) (append (reverse i) items)]
+                     [(txexpr-attrs? i) (append (append* (map (λ([a : Txexpr-Attr]) (reverse a)) i)) items)]
                      [else (cons i items)]))))
   (define/typed (make-key-value-list items)
     ((Listof (U Can-Be-Txexpr-Attr-Key Can-Be-Txexpr-Attr-Value)) -> (Listof (Pairof Txexpr-Attr-Key Txexpr-Attr-Value)))
-    (if (>= (length items) 2)
+    (if (< (length items) 2)
         null
         (let ([key (->txexpr-attr-key (car items))]
               [value (->txexpr-attr-value (cadr items))]
@@ -175,7 +169,7 @@
 
 ;; convert list of alternating keys & values to attr
 (define/typed (merge-attrs . items)
-  (Txexpr-Attr * -> Txexpr-Attrs)
+  (Can-Be-Txexpr-Attr * -> Txexpr-Attrs)
   (define attrs-hash (apply attrs->hash items))
   ;; sort needed for predictable results for unit tests
   (define sorted-hash-keys (sort (hash-keys attrs-hash) (λ([a : Txexpr-Tag][b : Txexpr-Tag]) (string<? (->string a) (->string b)))))
@@ -189,52 +183,59 @@
         (make-txexpr tag null (map remove-attrs elements)))
       x))
 
-#|
 
-;; todo: exclude-proc will keep things out, but is there a way to keep things in?
-(define+provide+safe (map-elements/exclude proc x exclude-test)
-  (procedure? txexpr? procedure? . -> . txexpr?)
+
+(define/typed (map-elements/exclude proc x exclude-test)
+  ((Xexpr -> Xexpr) Xexpr (Xexpr -> Boolean) -> Xexpr)
   (cond
     [(txexpr? x) 
      (if (exclude-test x)
          x
          (let-values ([(tag attr elements) (txexpr->values x)])
            (make-txexpr tag attr 
-                        (map (λ(x)(map-elements/exclude proc x exclude-test)) elements))))]
+                        (map (λ([x : Xexpr])(map-elements/exclude proc x exclude-test)) elements))))]
     ;; externally the function only accepts txexpr,
     ;; but internally we don't care
     [else (proc x)]))
 
-(define+provide+safe (map-elements proc x)
-  (procedure? txexpr? . -> . txexpr?)
+
+(define/typed (map-elements proc x)
+  ((Xexpr -> Xexpr) Xexpr -> Xexpr)
   (map-elements/exclude proc x (λ(x) #f)))
 
+
 ;; function to split tag out of txexpr
-(define+provide+safe (splitf-txexpr tx pred [proc (λ(x) null)])
-  ((txexpr? procedure?) (procedure?) . ->* . (values txexpr? txexpr-elements?))
-  (define matches null)
-  (define (do-extraction x)
+(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 matches : Txexpr-Elements null)
+  (define/typed (do-extraction x)
+    (Xexpr -> Xexpr)
     (cond
       [(pred x) (begin  ; store matched item and return processed value
                   (set! matches (cons x matches))
                   (proc x))]
-      [(txexpr? x) (let-values([(tag attr body) (txexpr->values x)]) 
-                     (make-txexpr tag attr (do-extraction body)))]
-      [(txexpr-elements? x) (filter (compose1 not null?) (map do-extraction x))]
+      [(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
-  (values tx-extracted (reverse matches))) 
-
-(define+provide+safe (xexpr->html x)
-  (xexpr? . -> . string?)
-  (define (->cdata x)
-    (if (cdata? x) x (cdata #f #f x)))
-  
-  (xexpr->string (let loop ([x x])
+  (values (if (txexpr? tx-extracted)
+              tx-extracted
+              (error 'splitf-txexpr "Can't get here")) (reverse matches)))
+
+
+(define/typed (xexpr->html x)
+  (Xexpr -> String)
+  (define/typed (->cdata x)
+    (Xexpr -> Xexpr)
+    (cond
+      [(cdata? x) x]
+      [(string? x) (cdata #f #f  (format "<![CDATA[~a]]>" x))]
+      [else x]))
+  (xexpr->string (let loop : Xexpr ([x : Xexpr x])
                    (cond
                      [(txexpr? x) (if (member (get-tag x) '(script style))
                                       (make-txexpr (get-tag x) (get-attrs x) (map ->cdata (get-elements x)))
                                       (make-txexpr (get-tag x) (get-attrs x) (map loop (get-elements x))))]
                      [else x]))))
 
-|#
\ No newline at end of file
diff --git a/typed/txexpr/tests.rkt b/typed/txexpr/tests.rkt
new file mode 100644
index 0000000..55a0b28
--- /dev/null
+++ b/typed/txexpr/tests.rkt
@@ -0,0 +1,159 @@
+#lang typed/racket/base
+(require (for-syntax racket/base))
+(require "main.rkt" typed/rackunit)
+
+(define-syntax (values->list stx)
+  (syntax-case stx ()
+    [(_ values-expr) #'(call-with-values (λ () values-expr) list)]))
+
+(check-true (txexpr-tag?'foo))
+(check-false (txexpr-tag? "foo"))
+(check-false (txexpr-tag? 3))
+
+(check-true (txexpr-attr? '(key "value")))
+(check-false (txexpr-attr? '(key "value" "another")))
+(check-false (txexpr-attr? '(key 0 "value")))
+
+(check-true (txexpr-attrs? '()))
+(check-true (txexpr-attrs? '((key "value"))))
+(check-true (txexpr-attrs? '((key "value") (foo "bar"))))
+(check-false (txexpr-attrs? '((key "value") "foo" "bar"))) ; content, not attr
+(check-false (txexpr-attrs? '(key "value"))) ; not a nested list
+(check-false (txexpr-attrs? '(("key" "value")))) ; two strings
+(check-false (txexpr-attrs? '((key value)))) ; two symbols
+
+(check-true (txexpr-element? "string"))
+(check-true (txexpr-element? 'amp))
+(check-true (txexpr-element? '(p "string")))
+(check-true (txexpr-element? 65)) ;; a valid-char
+(check-false (txexpr-element? 0)) ;; not a valid-char
+
+(check-true (txexpr-elements? '("p" "foo" "123")))
+(check-true (txexpr-elements? '("p" "foo" 123))) ; includes number
+(check-true (txexpr-elements? '(p "foo" "123"))) ; includes symbol
+(check-false (txexpr-elements? "foo")) ; not a list
+(check-false (txexpr-elements? '(((key "value")) "foo" "bar"))) ; includes attr
+(check-false (txexpr-elements? '("foo" "bar" ((key "value"))))) ; malformed
+
+(check-true (txexpr? '(p)))
+(check-true (txexpr? '(p "foo" "bar")))
+(check-true (txexpr? '(p ((key "value")) "foo" "bar")))
+(check-true (txexpr? '(p 123))) ; content is a number
+(check-false (txexpr? "foo")) ; not a list with symbol
+(check-false (txexpr? '(p "foo" "bar" ((key "value"))))) ; malformed
+(check-false (txexpr? '("p" "foo" "bar"))) ; no name
+
+(check-equal? (make-txexpr 'p) '(p))
+(check-equal? (make-txexpr 'p '((key "value"))) '(p ((key "value"))))
+(check-equal? (make-txexpr 'p null '("foo" "bar")) '(p "foo" "bar"))
+(check-equal? (make-txexpr 'p '((key "value")) (list "foo" "bar")) 
+              '(p ((key "value")) "foo" "bar"))
+
+(check-equal? (values->list (txexpr->values '(p))) 
+              (values->list (values 'p null null)))
+(check-equal? (values->list (txexpr->values '(p "foo"))) 
+              (values->list (values 'p null '("foo"))))
+(check-equal? (values->list (txexpr->values '(p ((key "value"))))) 
+              (values->list (values 'p '((key "value")) null)))
+(check-equal? (values->list (txexpr->values '(p ((key "value")) "foo"))) 
+              (values->list (values 'p '((key "value")) '("foo"))))
+
+(check-equal? (values->list (txexpr->values '(p))) 
+              (txexpr->list '(p)))
+(check-equal? (values->list (txexpr->values '(p "foo"))) 
+              (txexpr->list '(p "foo")))
+(check-equal? (values->list (txexpr->values '(p ((key "value"))))) 
+              (txexpr->list '(p ((key "value")))))
+(check-equal? (values->list (txexpr->values '(p ((key "value")) "foo"))) 
+              (txexpr->list '(p ((key "value")) "foo")))
+
+(check-equal? (get-tag '(p ((key "value"))"foo" "bar" (em "square"))) 'p)
+(check-equal? (get-attrs '(p ((key "value"))"foo" "bar" (em "square"))) '((key "value")))
+(check-equal? (get-elements '(p ((key "value"))"foo" "bar" (em "square"))) 
+              '("foo" "bar" (em "square")))
+
+
+(check-equal? (->txexpr-attr-key "foo") 'foo)
+(check-equal? (->txexpr-attr-key 'foo) 'foo)
+
+(check-equal? (->txexpr-attr-value "foo") "foo")
+(check-equal? (->txexpr-attr-value 'foo) "foo")
+
+(check-equal? (attrs->hash '((foo "bar"))) '#hash((foo . "bar")))
+(check-equal? (attrs->hash '((foo "bar")) '(foo "fraw")) '#hash((foo . "fraw")))
+(check-equal? (attrs->hash '((foo "bar")) '(foo "fraw") 'foo "dog") '#hash((foo . "dog")))
+
+(check-equal? (hash->attrs '#hash((foo . "bar")(hee . "haw"))) '((foo "bar")(hee "haw")))
+
+(check-equal? (attr-ref '(p ((foo "bar"))) 'foo) "bar")
+(check-equal? (attr-set '(p ((foo "bar"))) 'foo "fraw") '(p ((foo "fraw"))))
+
+(check-true (attrs-have-key? '(p ((color "red")(shape "circle"))) 'color))
+(check-true (attrs-have-key? '(p ((color "red")(shape "circle"))) "color"))
+(check-false (attrs-have-key? '((color "red")(shape "circle")) 'nonexistent))
+
+(check-true (attrs-equal? '(p ((color "red")(shape "circle")))
+                          '(foo ((color "red")(shape "circle")))))
+
+(check-false (attrs-equal? '(p ((color "red")(shape "circle")))
+                          '(foo ((color "blue")(shape "circle")))))
+
+(check-true (attrs-equal? '(p ((color "red")(shape "circle")))
+                          '(foo ((shape "circle")(color "red")))))
+
+(check-false (attrs-equal? '(p ((color "red")(shape "circle")))
+                          '(foo ((color "red")))))
+
+(check-true (attrs-equal? '((color "red")(shape "circle"))
+                          '((color "red")(shape "circle"))))
+
+(check-false (attrs-equal? '((color "red")(shape "circle"))
+                          '((color "blue")(shape "circle"))))
+
+(check-true (attrs-equal? '((color "red")(shape "circle"))
+                          '((shape "circle")(color "red"))))
+
+(check-false (attrs-equal? '((color "red")(shape "circle"))
+                          '((color "red"))))
+
+
+
+(check-equal? (merge-attrs 'foo "bar") '((foo "bar")))
+(check-equal? (merge-attrs '(foo "bar")) '((foo "bar")))
+(check-equal? (merge-attrs '((foo "bar"))) '((foo "bar")))
+(check-equal? (merge-attrs "foo" 'bar) '((foo "bar")))
+(check-equal? (merge-attrs "foo" "bar" "goo" "gar") '((foo "bar")(goo "gar")))
+(check-equal? (merge-attrs (merge-attrs "foo" "bar" "goo" "gar") "hee" "haw") 
+              '((foo "bar")(goo "gar")(hee "haw")))
+(check-equal? (merge-attrs '((foo "bar")(goo "gar")) "foo" "haw") '((foo "haw")(goo "gar")))
+
+
+
+(check-equal? (remove-attrs '(p ((foo "bar")) "hi")) '(p "hi"))
+(check-equal? (remove-attrs '(p ((foo "bar")) "hi" (p ((foo "bar")) "hi"))) '(p "hi" (p "hi")))
+
+
+(check-equal? (map-elements (λ(x) (if (string? x) "boing" x))  
+                            '(p "foo" "bar" (em "square"))) 
+              '(p "boing" "boing" (em "boing")))
+
+
+(check-equal? (attr-ref* '(root ((foo "bar")) "hello" "world" (meta ((foo "zam")) "bar2") 
+                  (em ((foo "zam")) "goodnight" "moon")) 'foo) '("bar" "zam" "zam"))
+
+(check-equal? (attr-ref* '(root ((foo "bar")) "hello" "world" (meta ((foo "zam")) "bar2") 
+                  (em ((foo "zam")) "goodnight" "moon")) 'nonexistent-key) '())
+
+
+(define split-this-tx '(root (meta "foo" "bar") "hello" "world" (meta "foo2" "bar2") 
+                  (em "goodnight" "moon" (meta "foo3" "bar3"))))
+(define split-predicate (λ(x) (and (txexpr? x) (equal? 'meta (car x)))))
+(check-equal? (call-with-values (λ() (splitf-txexpr split-this-tx split-predicate)) list) 
+              (list '(root "hello" "world" (em "goodnight" "moon")) '((meta "foo" "bar") (meta "foo2" "bar2") (meta "foo3" "bar3"))))
+
+(define split-proc (λ(x) '(div "foo")))
+(check-equal? (call-with-values (λ() (splitf-txexpr split-this-tx split-predicate split-proc)) list) 
+              (list '(root (div "foo") "hello" "world" (div "foo") (em "goodnight" "moon" (div "foo"))) '((meta "foo" "bar") (meta "foo2" "bar2") (meta "foo3" "bar3"))))
+
+(check-equal? (xexpr->html '(root (script "3 > 2") "Why is 3 > 2?"))
+              "<root><script><![CDATA[3 > 2]]></script>Why is 3 &gt; 2?</root>")
\ No newline at end of file