Add `isnum` and some tests

src/env.c

@@ -189,6 +189,7 @@ struct Environment defaultEnv()
         {"=", &equ}, {">", &gth}, {"<", &lth},
         {"cat", &catObjects}, {"fil", &filter}, {"len", &len}, {"ap", &append},
         {"at", &at}, {"rest", &rest}, {"rev", &reverse},
+        {"isnum", &isNum},
     };
 
     for(unsigned i = 0; i < sizeof(symFuncs)/sizeof(symFuncs[0]); i++) {

src/pebblisp.c

@@ -364,6 +364,12 @@ Object reverse(Object _list, Object ignore, struct Environment *ignore2)
     return rev;
 }
 
+Object isNum(Object test, Object ignore, struct Environment *ignore2)
+{
+	return test.type == TYPE_NUMBER ?
+		boolObject(1) : boolObject(0);
+}
+
 void copySlice(char * dest, struct Slice *src)
 {
     if(!dest || !src)

src/pebblisp.h

@@ -54,4 +54,6 @@ Object at(Object index, Object list, struct Environment *env);
 Object rest(Object list, Object ignore, struct Environment *env);
 Object reverse(Object _list, Object ignore, struct Environment *ignore2);
 
+Object isNum(Object test, Object ignore, struct Environment *ignore2);
+
 #endif

src/tests.sh

@@ -86,6 +86,11 @@ check "StringEquality" "(= \"Bean\" \"Bean\" )" "T"
 check "StringInequality" "(= \"Beans\" \"Bean\" )" "F"
 endBlock
 
+title "TypeCheck"
+check "IsNum" "(isnum 23847123)" "T"
+check "IsntNum" "(isnum \"WORDS\")" "F"
+endBlock
+
 title "Ifs/Bools"
 check "IfReturn" "(if (T) 123456789 987654321)" "123456789"
 check "IfRetTwo" "(if F 123456789 987654321)" "987654321"