Refactored docs.

example2.c

@@ -20,20 +20,19 @@ int main(int argc, char *argv[])
     int err;
     te_expr *n = te_compile(expression, vars, 2, &err);
 
-    if (!err) {
+    if (n) {
         /* The variables can be changed here, and eval can be called as many
          * times as you like. This is fairly efficient because the parsing has
          * already been done. */
-        x = 3;
-        y = 4;
-        const double r = te_eval(n); printf("Result:\n\t%f\n", r); }
-    else {
+        x = 3; y = 4;
+        const double r = te_eval(n); printf("Result:\n\t%f\n", r);
+
+        te_free(n);
+    } else {
         /* Show the user where the error is at. */
         printf("\t%*s^\nError near here", err-1, "");
     }
 
-    /* te_free is safe to call on null. */
-    te_free(n);
 
     return 0;
 }