From c7d78159e38b5000841c213bfb88839a9ea95df3 Mon Sep 17 00:00:00 2001
From: Sam Caldwell <samc@ccs.neu.edu>
Date: Thu, 3 Jan 2019 14:01:09 -0500
Subject: [PATCH] require/typed - no contracts

---
 .../examples/roles/require:typed/client.rkt   |  5 +++
 .../examples/roles/require:typed/lib.rkt      |  5 +++
 racket/typed/roles.rkt                        | 32 +++++++++++++++++++
 3 files changed, 42 insertions(+)
 create mode 100644 racket/typed/examples/roles/require:typed/client.rkt
 create mode 100644 racket/typed/examples/roles/require:typed/lib.rkt

diff --git a/racket/typed/examples/roles/require:typed/client.rkt b/racket/typed/examples/roles/require:typed/client.rkt
new file mode 100644
index 0000000..8a3509b
--- /dev/null
+++ b/racket/typed/examples/roles/require:typed/client.rkt
@@ -0,0 +1,5 @@
+#lang typed/syndicate/roles
+
+(require/typed "lib.rkt" [x : Int])
+
+(displayln (+ x 1))
\ No newline at end of file
diff --git a/racket/typed/examples/roles/require:typed/lib.rkt b/racket/typed/examples/roles/require:typed/lib.rkt
new file mode 100644
index 0000000..04b8015
--- /dev/null
+++ b/racket/typed/examples/roles/require:typed/lib.rkt
@@ -0,0 +1,5 @@
+#lang racket
+
+(provide x)
+
+(define x 42)
\ No newline at end of file
diff --git a/racket/typed/roles.rkt b/racket/typed/roles.rkt
index ac18232..5c92c04 100644
--- a/racket/typed/roles.rkt
+++ b/racket/typed/roles.rkt
@@ -39,6 +39,7 @@
          match cond
          ;; require & provides
          require provide
+         require/typed
          require-struct
          )
 
@@ -350,6 +351,37 @@
   (define (untyped-ctor stx)
     (user-ctor-untyped-ctor (syntax-local-value stx (const #f)))))
 
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+;; Require & Provide
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+
+;; Import and ascribe a type from an untyped module
+;; TODO: this is where contracts would need to go
+(define-syntax (require/typed stx)
+  (syntax-parse stx
+    #:datum-literals (:)
+    [(_ lib [name:id : ty:type] ...)
+     #:with (name- ...) (format-ids "~a-" #'(name ...))
+     #:with (name+ ...) (assign-types #'((name- ty name) ...))
+     (syntax/loc stx
+       (begin-
+         (require (only-in lib [name name+] ...))
+         (define-syntax name (make-variable-like-transformer #'name+)) ...))]))
+
+;; Format identifiers in the same way
+;; FormatString (SyntaxListOf Identifier) -> (Listof Identifier)
+(define-for-syntax (format-ids fmt ids)
+  (for/list ([id (in-syntax ids)])
+    (format-id id fmt id)))
+
+;; (SyntaxListof (SyntaxList Identifier Type Identifier)) -> (Listof Identifier)
+;; For each triple (name- ty name),
+;; assign the ty to name- with the orig name
+(define-for-syntax (assign-types los)
+  (for/list ([iti (in-syntax los)])
+    (match-define (list name- ty name) (syntax->list iti))
+    (add-orig (assign-type name- ty #:wrap? #f) name)))
+
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 ;; Conveniences
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;