From 627477206914007246b2ffeacdc5aefdfcbe3b86 Mon Sep 17 00:00:00 2001
From: m455 <jesselaprade@gmail.com>
Date: Thu, 16 Jul 2020 10:26:22 -0400
Subject: [PATCH] Simplified pattern matching with match expander

---
 src/nicethings.rkt | 38 +++++++++++---------------------------
 1 file changed, 11 insertions(+), 27 deletions(-)

diff --git a/src/nicethings.rkt b/src/nicethings.rkt
index fce07bd..ffd11c2 100644
--- a/src/nicethings.rkt
+++ b/src/nicethings.rkt
@@ -304,35 +304,19 @@
   (define (args-ref number)
     (vector-ref vectorof-args number))
   (match vectorof-args
-    [(vector a)
-     (cond
-       [(ormap (lambda (x) (equal? a x))
-               (list help-command-1
-                     help-command-2
-                     help-command-3))
-        (help)]
-
-       [(equal? a ls-command)
-        (ls)]
-
-       [(equal? a init-command)
-        (init)]
-
-       [else (displayln-messages-ref 'error-incorrect-usage)])]
-
-    [(vector a _)
-     (cond
-       [(equal? a add-command)
-        (add (args-ref 1))]
-
-       [(equal? a rm-command)
-        (rm (args-ref 1))]
-
-       [else (displayln-messages-ref 'error-incorrect-usage)])]
-
+    [(or (vector (== help-command-1))
+         (vector (== help-command-2))
+         (vector (== help-command-3))) (help)]
+    [(vector (== ls-command))          (ls)]
+    [(vector (== init-command))        (init)]
+    [(vector (== add-command) _)       (add (args-ref 1))]
+    [(vector (== rm-command)  _)       (rm  (args-ref 1))]
     [(vector _ _ _ ...)
      (displayln-messages-ref 'error-too-many-arguments)]
-
+    [(vector _ _)
+     (displayln-messages-ref 'error-incorrect-usage)]
+    [(vector _)
+     (displayln-messages-ref 'error-incorrect-usage)]
     [_ (random-message)]))
 
 (define (main vectorof-args)