Fixed errors when entering empty input

Submitting an empty guess would cause the game to print one of the two
"Already guessed" lines, now it checks for empty input and ignores it
accordingly.

Also, I assigned the guess variable to an empty string at the end of the
game() loop to reset it because I realized that inputting empty strings
after a single guess would cause the same bug to re-appear because the
variable hadn't changed from last attempt.

main.go

@@ -168,14 +168,34 @@ func alreadyCorrect(gs string) (isGuess bool) {
 	return isAlreadyGuessed
 }
 
+func isEmpty(guess string) (isEmpty bool) {
+	isEmpty = false
+	if guess == "" {
+		isEmpty = true
+	}
+	return isEmpty
+}
+
 func game() {
 	for {
 		gameStatus()
 		checkLose()
 		checkWin()
 
-		fmt.Printf("Guess: ")
-		fmt.Scanln(&guess)
+	checkEmpty:
+		for {
+			fmt.Printf("Guess: ")
+			fmt.Scanln(&guess)
+
+			if isEmpty(guess) == false {
+				break checkEmpty
+			} else {
+				gameStatus()
+			}
+
+		}
+
+		// TODO: prevent players from inputting multiple characters, UTF-8 is gonna be a pain
 
 		if getLetter(guess) == true {
 			if alreadyCorrect(guess) == true {
@@ -197,6 +217,9 @@ func game() {
 				time.Sleep(1 * time.Second)
 			}
 		}
+		// Realized entering empty input would still cause "already guessed" errors
+		// because guess wasn't being reset
+		guess = ""
 	}
 }