info/labs/lab01/examples/Hanoi.amy

+object Hanoi
+	
+  def solve(n : Int(32)) : Int(32) = {
+    if (n < 1) { 
+      error("can't solve Hanoi for less than 1 plate")
+    } else {
+      if (n == 1) {
+        1
+      } else {
+        2 * solve(n - 1) + 1
+      }
+    }
+  }
+
+  Std.printString("Hanoi for 4 plates: " ++ Std.intToString(solve(4)))
+end Hanoi
\ No newline at end of file

info/labs/lab01/examples/Hello.amy

+object Hello
+  Std.printString("Hello " ++ "world!")
+end Hello

info/labs/lab01/examples/HelloInt.amy

+object HelloInt
+  Std.printString("What is your name?");
+  val name: String = Std.readString();
+  Std.printString("Hello " ++ name ++ "! And how old are you?");
+  val age: Int(32) = Std.readInt();
+  Std.printString(Std.intToString(age) ++ " years old then.")
+end HelloInt

info/labs/lab01/examples/Printing.amy

+object Printing
+  Std.printInt(0); Std.printInt(-222); Std.printInt(42);
+  Std.printBoolean(true); Std.printBoolean(false);
+  Std.printString(Std.digitToString(0));
+  Std.printString(Std.digitToString(5));
+  Std.printString(Std.digitToString(9));
+  Std.printString(Std.intToString(0));
+  Std.printString(Std.intToString(-111));
+  Std.printString(Std.intToString(22));
+  Std.printString("Hello " ++ "world!");
+  Std.printString("" ++ "")
+end Printing

info/labs/lab01/examples/TestLists.amy

+object TestLists 
+  val l: L.List = L.Cons(5, L.Cons(-5, L.Cons(-1, L.Cons(0, L.Cons(10, L.Nil())))));
+  Std.printString(L.toString(L.concat(L.Cons(1, L.Cons(2, L.Nil())), L.Cons(3, L.Nil()))));
+  Std.printInt(L.sum(l));
+  Std.printString(L.toString(L.mergeSort(l)))
+end TestLists

info/labs/lab01/lab01-README.md

+# Amy Lab 01: Interpreter
+
+Below you will find the instructions for the first lab assignment in which you will get to know and implement an interpreter for the Amy language.
+
+## Logistics
+
+As a reminder, the labs are done in groups of 2-3, please register on Moodle if not already done.
+
+We advice you to create a private git repository to track your work and collaborate.
+
+The labs are graded through Moodle assignments, similarly to Software Construction (CS-214) that you might have taken. You will have to submit your `.scala` files on Moodle and you will receive automatically a grade and feedback. You submit as many times as you want, only the last submission will be taken into account. The tests are the same as the ones you will receive for each lab, we do not use any hidden tests.
+
+For this first lab, you can download the initial project scaffold from this folder.
+
+## Part 1: Your first Amy programs
+
+Write two example Amy programs each make sure that they typecheck (see [Type check examples](#type-check-examples)). Put them under `/examples`. Please be creative when writing your programs: they should be nontrivial and not reproduce the functionality of the examples in the `/library` and `/examples` directories of the repository. Of course you are welcome to browse these directories for inspiration.
+
+Remember that you will use these programs in the remaining of the semester to test your compiler, so don't make them too trivial! Try to test many features of the language.
+
+If you have questions about how a feature of Amy works, you can always look at the [Amy Specification](../amy-specification/AmySpec.md). It's a good idea to keep a local copy of this document handy -- it will be your reference for whenever you are asked to implement an aspect of the Amy language throughout this semester.
+
+### Type check examples
+
+You can use the provided Frontend to type check your programs. To do so, run the provided bash script:
+
+```bash.sh
+./amytc.sh examples/your_program.amy
+```
+
+This will run the compiler frontend up to type checking and report either `Type checking successful!` or an error message. If you get an error message, you should fix the error before moving on to the next step.
+
+Please examine the bash scipt amytc.sh and its comments in your editor to understand how it works. Do not modify it.
+
+#### Troubleshooting
+
+- Your project must compile before you call the `amytc.sh` script.
+- If you get unexpected errors or behaviour, try to delete the `target/scala-3.5.2/amyc-assembly-1.7.jar` and retry.
+
+## Part 2: An Interpreter for Amy
+
+The main task of the first lab is to write an interpreter for Amy.
+
+### Interpreters
+
+The way to execute programs you have mostly seen so far is compilation to some kind of low-level code (bytecode for a virtual machine such as Java's; native binary code in case of languages such as C). An alternative way to execute programs is interpretation. According to Wikipedia, "an interpreter is a computer program that directly executes, i.e. performs, instructions written in a programming or scripting language, without previously compiling them into a machine language program". In other words, your interpreter is supposed to directly look at the code and *interpret* its meaning. For example, when encountering a call to the 'printString' function, your interpreter should print its argument on the standard output. This is the way Python is executing your code.
+
+### The general structure of the Interpreter
+
+The skeleton of the assignment is provided by us as an `sbt` project. See the [Implementation skeleton](#implementation-skeleton) section for more details.
+
+You will modify the `Interpreter.scala` file.
+
+In `Main.scala` you find the main method which is the entry point to your program. After processing the command line arguments of the interpreter, the main method creates a Pipeline, which contains the different stages of the compiler which you will implement in the future labs. The Pipeline will first call the Amy frontend, which will parse the source program into an abstract syntax tree (AST) and check it for correctness according to the [Amy Specification](../amy-specification/AmySpec.md), and then passes the result to the Interpreter.
+
+The AST abstracts away uninteresting things of the program (e.g. parentheses, whitespace, operator precedence...) and keeps the essential structure of the program. It describes the structure of programs recursively. For example, here you have the description of a module in Amy:
+
+`Module ::= **object** Id Definition* Expr? **end** Id`
+
+and in the implementation we find a class:
+
+`case class ModuleDef(name: Identifier, defs: List[ClassOrFunDef], optExpr: Option[Expr]) extends Definition`
+
+A comparison of the implementation of ASTs in Java (as shown in the book) and Scala is instructive.
+
+You can find the source code of the AST in the [TreeModule.scala](./src/amyc/ast/TreeModule.scala).
+
+### The Interpreter class
+
+Now let's delve into `Interpreter.scala`. This file currently only contains a partial implementation, and it is your task to complete it! The entrypoint into the interpreter is `interpret`, which takes an expression as input and executes its meaning. The main loop at the end of the class will just take the modules in order and interpret their expression, if present.
+
+`interpret` returns a `Value`, which is a type that represents a value that an Amy expression can produce. Value is inherited by classes which represent the different types of values present in Amy (`Int(32)`, `Booleans`, `Unit`, `String` and ADT values). `Value` has convenience methods to cast to `Int(32)`, `Boolean` and `String` (`as*`). Remember we can always call these methods safely when we know the types of an expression (e.g. the operands of an addition), since we know that the program type-checks.
+
+`interpret` takes an additional implicit parameter as an argument, which is a mapping from variables to values (in the interpreted language). In Scala, when an implicit parameter is expected, the compiler will look in the scope for some binding of the correct type and pass it automatically. This way we do not have to pass the same mapping over and over to all recursive calls to `interpret`. Be aware, however, that there are some cases when you need to change the `locals` parameter! Think carefully about when you have to do so.
+
+A few final notes:
+
+- You can print program output straight to the console.
+- You can assume the input programs are valid. This is guaranteed by the Amy frontend.
+- To find constructors and functions in the program, you have to search in the `SymbolTable` passed along with the program. To do so, use the three helper methods provided in the interpreter:
+  - `isConstrutor` will return whether the `Identifier` argument is a type constructor in the program
+  - `findFunctionOwner` will return the module which contains the given `Identifier`, which has to be a function in the program. E.g. if you give it the `printInt` function of the `Std` module, you will get the string `"Std"`.
+  - `findFunction` will return the function definition given a pair of Strings representing the module containing the function, and the function name. The return value is of type `FunDef` (see [the AST definitions](./src/amyc/ast/TreeModule.scala)).
+- When comparing Strings by reference, compare the two `StringValue`s directly and not the underlying Strings. The reason is that the JVM may return true when comparing Strings by equality when it is not expected (it has to do with JVM constant pools).
+- Some functions contained in the `Std` module are built-in in the language, i.e. they are hard-coded in the interpreter because they cannot be implemented in Amy otherwise. An example of a built-in function is `printString`. When you implement the interpreter for function calls, you should first check if the function is built-in, and if so, use the implementation provided in the `builtIns` map in the interpreter.
+- When a program fails (e.g. due to a call to `error` or a match fail), you should call the dedicated method in the Context: `ctx.reporter.fatal`.
+
+### Implementation skeleton
+
+You can get the project scaffold from [this folder](.).
+
+- `src/amyc/interpreter/Interpreter.scala` contains the partially implemented interpreter
+- `src/amyc/Main.scala` contains the `main` method which runs the interpreter on the input files
+- The `library` directory contains library definitions you can use in your Amy programs.
+- The `examples` directory contains some example programs on which you can try your implementation. Remember that most of them also use library files from `/library`. This should also contain the programs you wrote in Part 1.
+- `lib/amy-frontend-1.7.jar` contains the frontend of the compiler as a library, allowing you directly work with type-checked ASTs of input programs. You need this to be able to extract the AST from your source code to interpret it, as you did not implement this part of the compiler yet. This is also what allowed you to type check programs in part 1. **Note**: You are only allowed to use this binary code to link against your interpreter.
+
+You will have to complete the interpreter by implementing the missing methods (marked with the placeholder `???`).
+
+### Testing
+
+When you are done, use sbt to try some of your programs from Part 1:
+
+```bash
+  $ sbt
+  > run library/Std.amy examples/Hello.amy
+  Hello world!
+```
+
+You can also run your interpreter with the `amyi.sh` script in a similar way as you did with the type checker:
+
+```bash
+  $ ./amyi.sh examples/Hello.amy
+  Hello world!
+```
+
+**Note**: if you use this method, you have to delete `target/scala-3.5.2/amyc-assembly-1.7.jar` before running the script when you modified your interpreter. Otherwise, the script will reuse the previously compiled version of the interpreter and your new modifications would not be taken into account. Therefore this method is more recommended for testing multiple amy programs, rather than testing your interpreter while you are developing it.
+
+There is also testing infrastructure under `/test`. To add your own tests, you have to add your testcases under `/test/resources/interpreter/passing`
+and the expected output under `/test/resources/interpreter/outputs`.
+Then, you have to add the name of the new test in `InterpreterTests`, similarly to the examples given.
+To allow a test to also use the standard library (e.g., `Std.printString`), you can copy `Std.scala` from `library/Std.scala` to `/test/resources/interpreter/passing`.
+
+For example, to add a test that expects only "Hello world" to be printed, you can add `/test/resources/interpreter/passing/Hello.amy` containing:
+
+```scala
+object Hello 
+  Std.printString("Hello world") 
+end Hello
+```
+
+and `/test/resources/interpreter/outputs/Hello.txt` containing
+
+```text
+Hello world
+
+```
+
+(with a newline in the end!).
+
+You will also have to add a line to `/test/scala/amyc/test/InterpreterTests.scala`:  `@Test def testHello = shouldOutput(List("Std", "Hello"), "Hello")`. This will pass both files `Std.amy` and `Hello.amy` as inputs of the test. When you now run `test` from sbt, you should see the additional test case (called `testHello`).
+
+The tests provided originally in `test/` are the ones used to grade your work on Moodle. Please note that the grade returned by the grader on Moodle is what you will get for the lab. Therefore you should submit regularly on Moodle to validate your progress. Also, if tests pass locally but not on the grader, the grader is the one that counts so submit your work regularly and check the feedback in case of discrepancies.
+
+### Deliverables
+
+You should submit the following files on Moodle:
+
+- `Interpreter.scala` with your implementation of the interpreter
+
+Deadline: **07.03.2025 23:59:59**
+
+#### Related documentation
+
+- End of Chapter 1 in the Tiger Book presents a similar problem for another mini-language. A comparison of the implementation of ASTs in Java (as shown in the book) and Scala is instructive.

info/labs/lab01/library/List.amy

+object L 
+  abstract class List
+  case class Nil() extends List
+  case class Cons(h: Int(32), t: List) extends List
+ 
+  def isEmpty(l : List): Boolean = { l match {
+    case Nil() => true
+    case _ => false 
+  }}
+
+  def length(l: List): Int(32) = { l match {
+    case Nil() => 0
+    case Cons(_, t) => 1 + length(t)
+  }}
+
+  def head(l: List): Int(32) = {
+    l match {
+      case Cons(h, _) => h
+      case Nil() => error("head(Nil)")
+    }
+  }
+
+  def headOption(l: List): O.Option = {
+    l match {
+      case Cons(h, _) => O.Some(h)
+      case Nil() => O.None()
+    }
+  }
+
+  def reverse(l: List): List = {
+    reverseAcc(l, Nil())
+  }
+
+  def reverseAcc(l: List, acc: List): List = {
+    l match {
+      case Nil() => acc
+      case Cons(h, t) => reverseAcc(t, Cons(h, acc))
+    }
+  }
+
+  def indexOf(l: List, i: Int(32)): Int(32) = {
+    l match {
+      case Nil() => -1
+      case Cons(h, t) =>
+        if (h == i) { 0 }
+        else {
+          val rec: Int(32) = indexOf(t, i);
+          if (0 <= rec) { rec + 1 }
+          else { -1 }
+        }
+    }
+  }
+
+  def range(from: Int(32), to: Int(32)): List = {
+    if (to < from) { Nil() }
+    else {
+      Cons(from, range(from + 1, to))
+    }
+  }
+
+  def sum(l: List): Int(32) = { l match {
+    case Nil() => 0
+    case Cons(h, t) => h + sum(t)
+  }}
+
+  def concat(l1: List, l2: List): List = {
+    l1 match {
+      case Nil() => l2
+      case Cons(h, t) => Cons(h, concat(t, l2))
+    }
+  }
+
+  def contains(l: List, elem: Int(32)): Boolean = { l match {
+    case Nil() =>
+      false
+    case Cons(h, t) =>
+      h == elem || contains(t, elem)
+  }}
+
+  abstract class LPair
+  case class LP(l1: List, l2: List) extends LPair
+
+  def merge(l1: List, l2: List): List = {
+    l1 match {
+      case Nil() => l2
+      case Cons(h1, t1) =>
+        l2 match {
+          case Nil() => l1
+          case Cons(h2, t2) =>
+            if (h1 <= h2) {
+              Cons(h1, merge(t1, l2))
+            } else {
+              Cons(h2, merge(l1, t2))
+            }
+        }
+    }
+  }
+
+  def split(l: List): LPair = {
+    l match {
+      case Cons(h1, Cons(h2, t)) =>
+        val rec: LPair = split(t);
+        rec match {
+          case LP(rec1, rec2) =>
+            LP(Cons(h1, rec1), Cons(h2, rec2))
+        }
+      case _ =>
+        LP(l, Nil())
+    }
+  }
+  def mergeSort(l: List): List = {
+    l match {
+      case Nil() => l
+      case Cons(h, Nil()) => l
+      case xs =>
+        split(xs) match {
+          case LP(l1, l2) =>
+            merge(mergeSort(l1), mergeSort(l2))
+        }
+    }
+  }
+  
+  def toString(l: List): String = { l match {
+    case Nil() => "List()"
+    case more => "List(" ++ toString1(more) ++ ")"
+  }}
+
+  def toString1(l : List): String = { l match {
+    case Cons(h, Nil()) => Std.intToString(h)
+    case Cons(h, t) => Std.intToString(h) ++ ", " ++ toString1(t)
+  }}
+
+  def take(l: List, n: Int(32)): List = {
+    if (n <= 0) { Nil() }
+    else { 
+      l match {
+        case Nil() => Nil()
+        case Cons(h, t) =>
+          Cons(h, take(t, n-1))
+      }
+    }
+  }
+    
+end L

info/labs/lab01/library/Option.amy

+object O 
+  abstract class Option
+  case class None() extends Option
+  case class Some(v: Int(32)) extends Option
+
+  def isdefined(o: Option): Boolean = {
+    o match {
+      case None() => false
+      case _ => true
+    }
+  }
+
+  def get(o: Option): Int(32) = {
+    o match {
+      case Some(i) => i
+      case None() => error("get(None)")
+    }
+  }
+
+  def getOrElse(o: Option, i: Int(32)): Int(32) = {
+    o match {
+      case None() => i
+      case Some(oo) => oo
+    }
+  }
+
+  def orElse(o1: Option, o2: Option): Option = {
+    o1 match {
+      case Some(_) => o1
+      case None() => o2
+    }
+  }
+
+  def toList(o: Option): L.List = {
+    o match {
+      case Some(i) => L.Cons(i, L.Nil())
+      case None() => L.Nil()
+    }
+  }
+end O

info/labs/lab01/library/Std.amy

+/** This module contains basic functionality for Amy,
+  * including stub implementations for some built-in functions
+  * (implemented in WASM or JavaScript)
+  */
+object Std 
+  def printInt(i: Int(32)): Unit = {
+    error("") // Stub implementation
+  }
+  def printString(s: String): Unit = {
+    error("") // Stub implementation
+  }
+  def printBoolean(b: Boolean): Unit = {
+    printString(booleanToString(b))
+  }
+
+  def readString(): String = {
+    error("") // Stub implementation
+  }
+
+  def readInt(): Int(32) = {
+    error("") // Stub implementation
+  }
+
+  def intToString(i: Int(32)): String = {
+    if (i < 0) {
+      "-" ++ intToString(-i)
+    } else {
+      val rem: Int(32) = i % 10;
+      val div: Int(32) = i / 10;
+      if (div == 0) { digitToString(rem) }
+      else { intToString(div) ++ digitToString(rem) }
+    }
+  }
+  def digitToString(i: Int(32)): String = {
+    error("") // Stub implementation
+  }
+  def booleanToString(b: Boolean): String = {
+    if (b) { "true" } else { "false" }
+  }
+end Std

info/labs/lab01/project/build.properties

+sbt.version=1.10.7

info/labs/lab01/project/plugins.sbt

+addSbtPlugin("com.lightbend.sbt" % "sbt-proguard" % "0.3.0")
+
+addSbtPlugin("com.eed3si9n" % "sbt-assembly" % "1.2.0")
\ No newline at end of file

info/labs/lab01/src/amyc/Main.scala

+package amyc
+
+import utils._
+import interpreter.Interpreter
+
+import java.io.File
+
+object Main {
+  private def parseArgs(args: Array[String]): Context = {
+    var ctx = Context(new Reporter, Nil)
+    args foreach {
+      case "--interpret"   => ctx = ctx.copy(interpret = true)
+      case "--help"        => ctx = ctx.copy(help = true)
+      case "--type-check"  => ctx = ctx.copy(typeCheck = true)
+      case file            => ctx = ctx.copy(files = ctx.files :+ file)
+    }
+    ctx
+  }
+
+  def main(args: Array[String]): Unit = {
+    val ctx = parseArgs(args)
+    val pipelineInterpret = Frontend.pipeline.andThen(Interpreter)
+
+    if ctx.help then
+      println("Usage: amyc [ --interpret | --type-check ] file1.amy file2.amy ...")
+      sys.exit(0)
+    val files = ctx.files.map(new File(_))
+
+    try {
+      if (files.isEmpty) {
+        ctx.reporter.fatal("No input files")
+      }
+      files.find(!_.exists()).foreach { f =>
+        ctx.reporter.fatal(s"File not found: ${f.getName}")
+      }
+      if ctx.interpret then
+        pipelineInterpret.run(ctx)(files)
+      else if ctx.typeCheck then
+        Frontend.pipeline.run(ctx)(files)
+        println("Type checking successful!")
+      else
+        ctx.reporter.fatal("No action specified")
+      ctx.reporter.terminateIfErrors()
+    } catch {
+      case AmycFatalError(_) =>
+        sys.exit(1)
+    }
+  }
+}
\ No newline at end of file

labs/labs01_material/SymbolicTreeModule.scala → info/labs/lab01/src/amyc/ast/TreeModule.scala

@@ -2,16 +2,38 @@ package amyc.ast
 
 import amyc.utils.Positioned
 
-// Definitions of symbolic Amy syntax trees
-trait TreeModule {
+/* A polymorphic module containing definitions of Amy trees.
+ *
+ * This trait represents either nominal trees (where names have not been resolved)
+ * or symbolic trees (where names/qualified names) have been resolved to unique identifiers.
+ * This is done by having two type fields within the module,
+ * which will be instantiated differently by the two different modules.
+ *
+ */
+
+trait TreeModule { self =>
+  /* Represents the type for the name for this tree module.
+   * (It will be either a plain string, or a unique symbol)
+   */
+  type Name
+
+  // Represents a name within an module
+  type QualifiedName
+
+  // A printer that knows how to print trees in this module.
+  // The modules will instantiate it as appropriate
+  val printer: Printer { val treeModule: self.type }
+
   // Common ancestor for all trees
-  trait Tree extends Positioned
+  trait Tree extends Positioned {
+    override def toString: String = printer(this)
+  }
 
   // Expressions
   trait Expr extends Tree
 
   // Variables
-  case class Variable(name: Identifier) extends Expr
+  case class Variable(name: Name) extends Expr
 
   // Literals
   trait Literal[+T] extends Expr { val value: T }
@@ -37,8 +59,8 @@ trait TreeModule {
   case class Not(e: Expr) extends Expr
   case class Neg(e: Expr) extends Expr
 
-  // Function/ type constructor call
-  case class Call(qname: Identifier, args: List[Expr]) extends Expr
+  // Function/constructor call
+  case class Call(qname: QualifiedName, args: List[Expr]) extends Expr
   // The ; operator
   case class Sequence(e1: Expr, e2: Expr) extends Expr
   // Local variable definition
@@ -57,28 +79,38 @@ trait TreeModule {
 
   abstract class Pattern extends Tree
   case class WildcardPattern() extends Pattern // _
-  case class IdPattern(name: Identifier) extends Pattern // x
+  case class IdPattern(name: Name) extends Pattern // x
   case class LiteralPattern[+T](lit: Literal[T]) extends Pattern // 42, true
-  case class CaseClassPattern(constr: Identifier, args: List[Pattern]) extends Pattern // C(arg1, arg2)
+  case class CaseClassPattern(constr: QualifiedName, args: List[Pattern]) extends Pattern // C(arg1, arg2)
 
   // Definitions
-  trait Definition extends Tree { val name: Identifier }
-  case class ModuleDef(name: Identifier, defs: List[ClassOrFunDef], optExpr: Option[Expr]) extends Definition
+  trait Definition extends Tree { val name: Name }
+  case class ModuleDef(name: Name, defs: List[ClassOrFunDef], optExpr: Option[Expr]) extends Definition
   trait ClassOrFunDef extends Definition
-  case class FunDef(name: Identifier, params: List[ParamDef], retType: TypeTree, body: Expr) extends ClassOrFunDef {
+  case class FunDef(name: Name, params: List[ParamDef], retType: TypeTree, body: Expr) extends ClassOrFunDef {
     def paramNames = params.map(_.name)
   }
-  case class AbstractClassDef(name: Identifier) extends ClassOrFunDef
-  case class CaseClassDef(name: Identifier, fields: List[TypeTree], parent: Identifier) extends ClassOrFunDef
-  case class ParamDef(name: Identifier, tpe: TypeTree) extends Definition
+  case class AbstractClassDef(name: Name) extends ClassOrFunDef
+  case class CaseClassDef(name: Name, fields: List[TypeTree], parent: Name) extends ClassOrFunDef
+  case class ParamDef(name: Name, tt: TypeTree) extends Definition
 
   // Types
   trait Type
-  case object IntType extends Type 
-  case object BooleanType extends Type
-  case object StringType extends Type
-  case object UnitType extends Type
-  case class ClassType(qname: Identifier) extends Type
+  case object IntType extends Type {
+    override def toString: String = "Int"
+  }
+  case object BooleanType extends Type {
+    override def toString: String = "Boolean"
+  }
+  case object StringType extends Type {
+    override def toString: String = "String"
+  }
+  case object UnitType extends Type {
+    override def toString: String = "Unit"
+  }
+  case class ClassType(qname: QualifiedName) extends Type {
+    override def toString: String = printer.printQName(qname)(false).print
+  }
 
   // A wrapper for types that is also a Tree (i.e. has a position)
   case class TypeTree(tpe: Type) extends Tree
@@ -87,5 +119,24 @@ trait TreeModule {
   case class Program(modules: List[ModuleDef]) extends Tree
 }
 
-// Identifiers represent unique names in Amy
-class Identifier private(val name: String)
+/* A module containing trees where the names have not been resolved.
+ * Instantiates Name to String and QualifiedName to a pair of Strings
+ * representing (module, name) (where module is optional)
+ */
+object NominalTreeModule extends TreeModule {
+  type Name = String
+  case class QualifiedName(module: Option[String], name: String) {
+    override def toString: String = printer.printQName(this)(false).print
+  }
+  val printer = NominalPrinter
+}
+
+/* A module containing trees where the names have been resolved to unique identifiers.
+ * Both Name and ModuleName are instantiated to Identifier.
+ */
+object SymbolicTreeModule extends TreeModule {
+  type Name = Identifier
+  type QualifiedName = Identifier
+  val printer = SymbolicPrinter
+}
+

info/labs/lab01/test/resources/execution/failing/BasicError.grading.amy

+object BasicError
+
+	def throwError(msg: String): Unit = {
+		error(msg)
+	}
+
+	throwError("basic error test")
+end BasicError

info/labs/lab01/test/resources/execution/failing/Division.grading.amy

+object Division
+  1/0
+end Division

info/labs/lab01/test/resources/execution/failing/Locals.grading.amy

+object Locals
+  def foo(i: Int(32)): Int(32) = {
+    val i: Int(32) = 0;
+    if (i == 0) { error("") }
+    else { 0 }
+  }
+
+  foo(1)
+end Locals