Add int-string? to check if a string is a number.

src/cipher_analytical_machine/parsers/parsers.clj

@@ -8,6 +8,12 @@
   (if (re-matches #"\d+" str)
     true false))
 
+(defn int-string?
+  "Return true if the string is an signed integer."
+  [str]
+  (if (re-matches #"[+-]?\b\d+\b" str)
+    true false))
+
 (defn parse-unsigned-int
   "Return an integer if the argument is an integer."
   [str-or-int]

test/cipher_analytical_machine/parsers/parsers_test.clj

@@ -16,6 +16,18 @@
       "-10" false
       "abc" false)))
 
+(deftest int-string?-test
+  (testing "The function return true only for an singned integer as a string."
+    (are [str expected]
+        (= expected
+           (int-string? str))
+      "9" true
+      "10" true
+      "-10" true
+      "asd -10 " false
+      " -10 " false
+      "abc" false)))
+
 (deftest parse-unsigned-int-test
   (testing "The function parse the integer if the string is an integer."
     (are [str-or-int expected]