parser: major refinement of error handling

tool/build.gradle.kts

@@ -13,6 +13,7 @@ dependencies {
 application {
   applicationName = "pork"
   mainClass.set("gay.pizza.pork.tool.MainKt")
+  applicationDefaultJvmArgs += "-XstartOnFirstThread"
 }
 
 for (task in arrayOf(tasks.shadowDistTar, tasks.shadowDistZip, tasks.shadowJar)) {

tool/src/main/kotlin/gay/pizza/pork/tool/TokenizeCommand.kt

@@ -12,7 +12,7 @@ class TokenizeCommand : CliktCommand(help = "Tokenize Compilation Unit", name =
     val tool = FileTool(PlatformFsProvider.resolve(path))
     val tokenStream = tool.tokenize()
     for (token in tokenStream.tokens) {
-      println("${token.start} ${token.type.name} '${sanitize(token.text)}'")
+      println("${token.sourceIndex.index} ${token.type.name} '${sanitize(token.text)}'")
     }
   }