frontend: implement basic scope analysis

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

@@ -15,7 +15,8 @@ class RootCommand : CliktCommand(
       ReprintCommand(),
       ParseCommand(),
       AstCommand(),
-      AttributeCommand()
+      AttributeCommand(),
+      ScopeAnalysisCommand()
     )
   }
 

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

@@ -0,0 +1,27 @@
+package gay.pizza.pork.tool
+
+import com.github.ajalt.clikt.core.CliktCommand
+import com.github.ajalt.clikt.parameters.arguments.argument
+import gay.pizza.dough.fs.PlatformFsProvider
+import gay.pizza.pork.frontend.scope.WorldScope
+import gay.pizza.pork.minimal.FileTool
+
+class ScopeAnalysisCommand : CliktCommand(help = "Run Scope Analysis", name = "scope-analysis") {
+  val path by argument("file")
+
+  override fun run() {
+    val tool = FileTool(PlatformFsProvider.resolve(path))
+    val world = tool.buildWorld()
+    val root = world.load(tool.rootImportLocator)
+    val scope = WorldScope(world).apply { index(root) }
+    val rootScope = scope.scope(root)
+    val visibleScopeSymbols = rootScope.findInternallyVisibleSymbols()
+    for (visibleScopeSymbol in visibleScopeSymbols) {
+      println(
+        "symbol ${visibleScopeSymbol.scopeSymbol.symbol.id} " +
+        "type=${visibleScopeSymbol.scopeSymbol.definition.type.name} " +
+        "internal=${visibleScopeSymbol.isInternalSymbol}"
+      )
+    }
+  }
+}