From 930c56947e7ef1be14b33618dcb10136fc5d04a4 Mon Sep 17 00:00:00 2001
From: David Florness <david@florness.com>
Date: Sat, 22 Feb 2020 20:19:04 -0700
Subject: [PATCH] Move polynomial functionality to separate file

---
 client.rkt | 15 +--------------
 poly.rkt   | 25 +++++++++++++++++++++++++
 2 files changed, 26 insertions(+), 14 deletions(-)
 create mode 100644 poly.rkt

diff --git a/client.rkt b/client.rkt
index c716954..96e6ee7 100644
--- a/client.rkt
+++ b/client.rkt
@@ -33,20 +33,7 @@
   [#:struct (exn:fail:network:http:error exn:fail:network) ([code : Any] [type : Any])])
 (require/typed crypto
   [crypto-random-bytes (Natural -> Bytes)])
-
-(define num-bytes (assert (/ 1024 8) natural?))
-
-(define (gen)
-  (let* ([bstr (crypto-random-bytes num-bytes)])
-    (cast (bytes->integer bstr #f #t 0 num-bytes) Natural)))
-
-(define (random-poly [degree : Natural] [constant : Natural])
-  (let ([coefficients (build-vector degree (λ (_) (gen)))])
-    (λ ([x : Natural]) : Natural
-       (cast (+ constant
-                (for/sum : Integer ([i degree])
-                  (* (expt x (add1 i)) (vector-ref coefficients i))))
-             Natural))))
+(require "poly.rkt")
 
 (define (natural->hex-string [n : Natural])
   (bytes->hex-string
diff --git a/poly.rkt b/poly.rkt
new file mode 100644
index 0000000..251498f
--- /dev/null
+++ b/poly.rkt
@@ -0,0 +1,25 @@
+#lang typed/racket
+(require/typed binaryio
+  [bytes->integer (->* (Bytes Boolean) (Boolean Natural Natural) Integer)]
+  [integer->bytes (->* (Integer Natural Boolean) (Boolean Bytes Natural) Bytes)]
+  [integer-bytes-length (Integer Boolean -> Natural)])
+(require/typed crypto
+  [crypto-random-bytes (Natural -> Bytes)])
+
+(define-type Poly (Natural -> Natural))
+
+(define num-bytes (assert (/ 1024 8) natural?))
+
+(define (gen)
+  (let* ([bstr (crypto-random-bytes num-bytes)])
+    (cast (bytes->integer bstr #f #t 0 num-bytes) Natural)))
+
+(define (random-poly [degree : Natural] [constant : Natural]) : Poly
+  (let ([coefficients (build-vector degree (λ (_) (gen)))])
+    (λ ([x : Natural]) : Natural
+       (cast (+ constant
+                (for/sum : Integer ([i degree])
+                  (* (expt x (add1 i)) (vector-ref coefficients i))))
+             Natural))))
+
+(provide (all-defined-out))
-- 
2.38.4