Simple Language Interpreter

simple_language_interpreter.kt

fun main() {

    val testCode = """
        x = 3 
        print(x)
    """

    val program = compile(testCode)

    program.execute()
}

fun compile(code: String): CompiledProgram {

    val compiledProgram = CompiledProgram()

    code.lineSequence()
            .filter { it.isNotBlank() }
            .map { it.trim() }
            .forEach { line ->
                compiledProgram.instructions += Token.values().first { it.pattern.matches(line) }.compileFunction(line, compiledProgram)
            }

    return compiledProgram
}
class CompiledProgram {

    val variables = mutableMapOf<String,Int>()
    val instructions = mutableListOf<() -> Unit>()

    fun execute() {
        instructions.forEach { it() }
    }
}

enum class Token(val pattern: Regex) {

    VARIABLE_ASSIGN(Regex("[a-z][0-9a-z]* = [0-9]+")) {

        val extractVariableName = Regex("[a-z][0-9a-z]*(?= =[0-9]+)")
        val extractVariableValue = Regex("(?<== )[0-9]+")

        override fun compileFunction(subCode: String, compiledProgram: CompiledProgram): () -> Unit {
            return {
                val variableName = extractVariableName.find(subCode)?.value!!
                val variableValue = extractVariableValue.find(subCode)?.value!!.toInt()
                compiledProgram.variables[variableName] = variableValue
            }
        }
    },
    PRINT(Regex("print\\([0-9a-z]+\\)")) {

        val extractPrintStr = Regex("(?<=print\\()[0-9a-z]+(?=\\))")

        override fun compileFunction(subCode: String, compiledProgram: CompiledProgram): () -> Unit {
            return { println(extractPrintStr.find(subCode)?.value) }
        }
    },
    VARIABLE_GET(Regex("[a-z][0-9a-z]*")) { 
        
    }
    ;/*,
    IF(Regex("if\\(.+\\)")),
    PLUS(Regex("[0-9a-z]+ \\+ [0-9a-z]+"))*/

    abstract fun compileFunction(subCode: String, compiledProgram: CompiledProgram): () -> Unit
}