Code cleanup

app/src/main/kotlin/android/emu6502/Assembler.kt

@@ -7,7 +7,6 @@ import java.util.regex.Pattern
 
 class Assembler(private var memory: Memory, private val symbols: Symbols) {
   var codeLen = 0
-  val BOOTSTRAP_ADDRESS = 0x600
   var defaultCodePC = BOOTSTRAP_ADDRESS
   private var labels = Labels(this, symbols)
 
@@ -35,7 +34,7 @@ class Assembler(private var memory: Memory, private val symbols: Symbols) {
     sanitizedLines
         .map { pattern.matcher(it) }
         .filter { it.find() }
-        .forEach { symbols.put(it.group(1), sanitize(it.group(2))) }
+        .forEach { symbols[it.group(1)] = sanitize(it.group(2)) }
 
     return sanitizedLines.filterNot { pattern.matcher(it).find() }
   }
@@ -85,10 +84,10 @@ class Assembler(private var memory: Memory, private val symbols: Symbols) {
       return true
     }
 
-    if (input.matches("^\\w+\\s+.*?$".toRegex())) {
-      param = input.replace("^\\w+\\s+(.*?)".toRegex(), "$1")
+    param = if (input.matches("^\\w+\\s+.*?$".toRegex())) {
+      input.replace("^\\w+\\s+(.*?)".toRegex(), "$1")
     } else if (input.matches("^\\w+$".toRegex())) {
-      param = ""
+      ""
     } else {
       return false
     }
@@ -419,4 +418,8 @@ class Assembler(private var memory: Memory, private val symbols: Symbols) {
     pushByte(opcode)
     return true
   }
+
+  companion object {
+    const val BOOTSTRAP_ADDRESS = 0x600
+  }
 }

app/src/main/kotlin/android/emu6502/Display.kt

@@ -10,7 +10,7 @@ import android.view.View
 open class Display(context: Context, attrs: AttributeSet) : View(context, attrs) {
   private val numX = 32
   private val numY = 32
-  private val matrix = Array(numX, { IntArray(numY) })
+  private val matrix = Array(numX) { IntArray(numY) }
 
   private val palette = arrayOf(
       "#000000", "#ffffff", "#880000", "#aaffee",

app/src/main/kotlin/android/emu6502/app/MainActivity.kt

@@ -13,41 +13,35 @@ import kotlinx.android.synthetic.main.activity_main.*
 import kotlinx.android.synthetic.main.toolbar.*
 
 class MainActivity : AppCompatActivity() {
-  private var emulator: Emulator? = null
+  private lateinit var emulator: Emulator
 
   override fun onCreate(savedInstanceState: Bundle?) {
     super.onCreate(savedInstanceState)
     setContentView(R.layout.activity_main)
     setSupportActionBar(toolbar)
-    val ab: ActionBar = supportActionBar!!
-    ab.setDisplayHomeAsUpEnabled(true)
-
+    val actionBar: ActionBar = supportActionBar!!
+    actionBar.setDisplayHomeAsUpEnabled(true)
     fabRun.setOnClickListener {
       display_wrapper.visibility = View.VISIBLE
       emulator = Emulator(display)
-      val emu: Emulator = emulator as Emulator
-      emu.assembler.assembleCode(txtInstructions.text.toString().split("\n"))
+      emulator.assembler.assembleCode(txtInstructions.text.toString().split("\n"))
       Snackbar.make(layout_content,
-          "Code assembled successfully, ${emu.assembler.codeLen} bytes.",
+          "Code assembled successfully, ${emulator.assembler.codeLen} bytes.",
           Snackbar.LENGTH_SHORT).show()
-      emu.cpu.run()
+      emulator.cpu.run()
     }
 
     btnReset.setOnClickListener {
-      val emu: Emulator = emulator as Emulator
-      emu.reset()
+      emulator.reset()
     }
 
     val onClickButton = { code: Int ->
-      if (emulator != null) {
-        val emu = emulator as Emulator
-        emu.cpu.memory.storeKeypress(code)
-      }
+      emulator.cpu.memory.storeKeypress(code)
     }
-    arrowLeft.setOnClickListener  { onClickButton(0x61) }
+    arrowLeft.setOnClickListener { onClickButton(0x61) }
     arrowRight.setOnClickListener { onClickButton(0x64) }
-    arrowUp.setOnClickListener    { onClickButton(0x77) }
-    arrowDown.setOnClickListener  { onClickButton(0x73) }
+    arrowUp.setOnClickListener { onClickButton(0x77) }
+    arrowDown.setOnClickListener { onClickButton(0x73) }
   }
 
   override fun onCreateOptionsMenu(menu: Menu?): Boolean {