Command-line 'Set' Game in Kotlin 4

February 11, 2025

Part 4: Creating a Playable Game Via Interactive Terminal

Creating a Pickable Grid

I decided again to ask GPT, how do I make this into a loop? And realized I needed to start at the core. I needed a grid-like access to be parsed from the CLI. So the way the end game is dealt, 3x4 cards come out. I'd like to compare them like this, 0,3 1,3, 2,3 So the pattern is x,y then a space for the next card. If I wanted, let's say 2nd card on the 3rd row, I'd give it 2,3.

class GridAccessor(private val rows: Int, private val cols: Int) {
    private val grid = Array(rows * cols) { "Item-${it + 1}" }

    fun indexOf(row: Char, col: Int): Int {
        val rowIndex = row.lowercaseChar() - 'a'
        require(rowIndex in 0 until rows) { "Invalid row: $row" }
        require(col in 1..cols) { "Invalid column: $col" }
        return rowIndex * cols + (col - 1)
    }

    operator fun get(row: Char, col: Int): String {
        val index = indexOf(row, col)
        return grid[index]
    }
}

Wrapping it in a Game Loop

This is quite the chunk of code but really it's pretty simple. We deal the cards, you enter in three that you think are a set, if it is a set we pop those cards off and shuffle new ones in place, if not, we simply repeat the loop. The annoying part is parsing text hopefully this will be improved by a mouse selection model, but for now it's playable!

fun main(){
    val cardsHash = createHashMap()
    val cards = cardsHash.entries.shuffled().toMutableList()
    var cardsDealt = cards.take(12)

    print(
        dealPlayableCards(
            cardsDealt.map{
                val card = it.value.first
                getAsciiCard(card)
            }
        )
    )

    println("Welcome to the Set Game")
    val grid = GridAccessor(rows = 3, cols = 4)

    while (true) {
        println("Enter 3 cells (ie. 'a1 b1 c1')")
        val input = readlnOrNull()?.lowercase()

        if (input == "exit") {
            println("Goodbye!")
            break
        }

        if (input != null && input.length == 8) {
            val row1 = input.first()
            val col1 = input.substring(1, 2).toInt()
            val card1index = grid.indexOf(row1, col1)
            val row2 = input.substring(3,4).first()
            val col2 = input.substring(4,5).toInt()
            val card2index = grid.indexOf(row2, col2)
            val row3 = input.substring(6,7).first()
            val col3 = input.substring(7,8).toInt()
            val card3index = grid.indexOf(row3, col3)

            try {
                val card1 = cardsDealt[card1index].value
                val card2 = cardsDealt[card2index].value
                val card3 = cardsDealt[card3index].value
                println("""${card1.second} |  ${card2.second}  |  ${card3.second} """)
                println("Are the selected cards a set?")
                val setEval = areCardsASet(card1.first, card2.first, card3.first)
                println(if(setEval) "YES" else "NO")
                if(setEval){
                    cards[card1index] = cards[12]
                    cards.removeAt(12)
                    cards[card2index] = cards[13]
                    cards.removeAt(13)
                    cards[card3index] = cards[14]
                    cards.removeAt(14)

                    cardsDealt = cards.take(12)
                    print(
                        dealPlayableCards(
                            cardsDealt.map{
                                val card = it.value.first
                                getAsciiCard(card)
                            }
                        )
                    )
                }
            } catch (e: IllegalArgumentException) {
                println(e.message)
            }
        } else {
            println("Invalid input. Please use the format 'a2' or type 'exit' to quit.")
        }
    }
}

I suggest you checkout the code from Github and give it a shot!