Add utils/date module.

2 files changed, 26 insertions, 3 deletions

diff --git a/readers/article.rkt b/readers/article.rkt
index df5e8e8..c60de16 100644
--- a/readers/article.rkt
+++ b/readers/article.rkt
@@ -3,7 +3,8 @@
 (provide read-article)
 
 (require "../entities/article.rkt")
-(require (only-in typed/srfi/19 string->date))
+(require (only-in "../utils/date.rkt" string->date))
+
 (require typed/json)
 (require typed/syntax/readerr)
 
@@ -19,9 +20,9 @@
      (define timestamp
        (let ([timestamp (hash-ref jse 'timestamp (thunk (k "timestamp not found")))])
          (unless (string? timestamp) (k "timestamp must be a string"))
-         (with-handlers ([exn:fail? (const #f)])
+         (with-handlers ([exn:fail? (lambda (_e)
+                                      (k "timestamp must be a iso8600 string"))])
            (string->date timestamp "~Y-~m-~dT~H:~M:~S~z"))))
-     (unless (date? timestamp) (k "timestamp must be a iso8600 string"))
 
      (define hash (hash-ref jse 'hash (thunk (k "hash not found"))))
      (unless (string? hash) (k "hash must be a string"))
diff --git a/utils/date.rkt b/utils/date.rkt
new file mode 100644
index 0000000..7019832
--- /dev/null
+++ b/utils/date.rkt
@@ -0,0 +1,22 @@
+#lang typed/racket
+
+(provide current-date
+         string->date
+         date->string)
+
+(require (only-in typed/racket/date current-date))
+(require (rename-in (only-in typed/srfi/19
+                             string->date
+                             date->string
+                             date?)
+                    [string->date string->Date]
+                    [date->string Date->string]
+                    [date? Date?]))
+
+(: string->date (-> String String date))
+(define (string->date str fmt)
+  (assert (string->Date str fmt) date?))
+
+(: date->string (->* (date) (String) String))
+(define (date->string d [f "~c"])
+  (Date->string (assert d Date?) f))