From 215f96c92ddf27762e352a38f03df9dc887dfa4c Mon Sep 17 00:00:00 2001
From: Wesley Kerfoot <wjak56@gmail.com>
Date: Sat, 28 Apr 2018 00:30:34 -0400
Subject: [PATCH] helper functions for handling shell env context manager

---
 shell_env.rkt | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)
 create mode 100644 shell_env.rkt

diff --git a/shell_env.rkt b/shell_env.rkt
new file mode 100644
index 0000000..a4ec5c2
--- /dev/null
+++ b/shell_env.rkt
@@ -0,0 +1,19 @@
+#lang racket
+
+(define shell-env
+  (make-parameter #hash()))
+
+(define (merge-hash h1 h2)
+  (define h1-vs (hash->list h1))
+  (define h2-vs  (hash->list h2))
+  (make-hash (append h1-vs h2-vs)))
+
+(define (merge-hashes . hs ...)
+  (foldl merge-hash #hash() hs))
+
+(define (set-vars vars)
+  (apply
+    merge-hashes
+    (list
+      (shell-env)
+      (make-hash vars))))