static bool Eval(WrenVM vm, Obj[] args, int stackStart)
{
if (args[stackStart + 1] is ObjString)
{
// Eval the code in the module where the calling function was defined.
Obj callingFn = vm.Fiber.GetFrame().Fn;
ObjModule module = (callingFn is ObjFn)
? ((ObjFn)callingFn).Module
: ((ObjClosure)callingFn).Function.Module;
// Compile it.
ObjFn fn = Compiler.Compile(vm, module, "", args[stackStart + 1].ToString(), false);
if (fn == null)
{
vm.Fiber.Error = Obj.MakeString("Could not compile source code.");
return false;
}
// TODO: Include the compile errors in the runtime error message.
// Create a fiber to run the code in.
ObjFiber evalFiber = new ObjFiber(fn) { Caller = vm.Fiber };
// Switch to the fiber.
args[stackStart] = evalFiber;
return false;
}
vm.Fiber.Error = Obj.MakeString("Source code must be a string.");
return false;
}
public Obj GetKey(int index)
{
if (index < 0 || index >= _entries.Count)
return Undefined;
Obj[] v = new Obj[_entries.Count];
_entries.Keys.CopyTo(v, 0);
return v[index];
}
// Removes [key] from [map], if present. Returns the value for the key if found
// or `NULL_VAL` otherwise.
public Obj Remove(Obj key)
{
Obj v;
if (!_entries.TryGetValue(key, out v))
return Null;
_entries.Remove(key);
return v;
}
// Resets [fiber] back to an initial state where it is ready to invoke [fn].
private void ResetFiber(Obj fn)
{
Stack = new Obj[InitialStackSize];
Capacity = InitialStackSize;
Frames = new List<CallFrame>();
// Push the stack frame for the function.
StackTop = 0;
NumFrames = 1;
OpenUpvalues = null;
Caller = null;
Error = null;
CallerIsTrying = false;
CallFrame frame = new CallFrame { Fn = fn, StackStart = 0, Ip = 0 };
Frames.Add(frame);
}
// TODO: The argument list here is getting a bit gratuitous.
// Creates a new function object with the given code and constants. The new
// function will take over ownership of [bytecode] and [sourceLines]. It will
// copy [constants] into its own array.
public ObjFn(ObjModule module,
Obj[] constants,
int numUpvalues, int arity,
byte[] bytecode, ObjString debugSourcePath,
string debugName, int[] sourceLines)
{
Bytecode = bytecode;
Constants = constants;
Module = module;
NumUpvalues = numUpvalues;
NumConstants = constants.Length;
Arity = arity;
/* Debug Information */
SourcePath = debugSourcePath;
Name = debugName;
SourceLines = sourceLines;
ClassObj = WrenVM.FnClass;
}
static bool prim_map_subscriptSetter(WrenVM vm, Obj[] args, int stackStart)
{
if (ValidateKey(args[stackStart + 1]))
{
ObjMap map = args[stackStart] as ObjMap;
if (map != null)
{
map.Set(args[stackStart + 1], args[stackStart + 2]);
}
args[stackStart] = args[stackStart + 2];
return true;
}
vm.Fiber.Error = Obj.MakeString("Key must be a value type or fiber.");
return false;
}
static bool prim_map_clear(WrenVM vm, Obj[] args, int stackStart)
{
ObjMap m = args[stackStart] as ObjMap;
if (m != null)
m.Clear();
args[stackStart] = Obj.Null;
return true;
}
// Looks up [key] in [map]. If found, returns the value. Otherwise, returns UNDEFINED.
public Obj Get(Obj key)
{
Obj v;
return(_entries.TryGetValue(key, out v) ? v : Undefined);
}
static bool prim_map_subscript(WrenVM vm, Obj[] args, int stackStart)
{
Obj a = args[stackStart + 1];
if (ValidateKey(a))
{
ObjMap map = args[stackStart] as ObjMap;
if (map != null)
{
args[stackStart] = map.Get(a);
if (args[stackStart] == Obj.Undefined)
{
args[stackStart] = Obj.Null;
}
}
else
{
args[stackStart] = Obj.Null;
}
return true;
}
vm.Fiber.Error = Obj.MakeString("Key must be a value type or fiber.");
return false;
}
static bool prim_fn_toString(WrenVM vm, Obj[] args, int stackStart)
{
args[stackStart] = Obj.MakeString("<fn>");
return true;
}
// Defines [methodValue] as a method on [classObj].
private static bool BindMethod(bool isStatic, int symbol, ObjClass classObj, Obj methodContainer)
{
// If we are binding a foreign method, just return, as this will be handled later
if (methodContainer is ObjString)
return true;
ObjFn methodFn = methodContainer as ObjFn ?? ((ObjClosure)methodContainer).Function;
Method method = new Method { MType = MethodType.Block, Obj = methodContainer };
if (isStatic)
classObj = classObj.ClassObj;
// Methods are always bound against the class, and not the metaclass, even
// for static methods, because static methods don't have instance fields
// anyway.
Compiler.BindMethodCode(classObj, methodFn);
classObj.BindMethod(symbol, method);
return true;
}
bool CheckArity(Obj[] args, int numArgs, int stackStart)
{
ObjFn fn = args[stackStart] as ObjFn;
ObjClosure c = args[stackStart] as ObjClosure;
if (c != null)
{
fn = c.Function;
}
if (fn == null)
{
Fiber.Error = Obj.MakeString("Receiver must be a function or closure.");
return false;
}
if (numArgs - 1 < fn.Arity)
{
Fiber.Error = Obj.MakeString("Function expects more arguments.");
return false;
}
return true;
}
private static bool prim_map_iterate(WrenVM vm, Obj[] args, int stackStart)
{
ObjMap map = (ObjMap)args[stackStart];
if (map.Count() == 0)
{
args[stackStart] = Obj.False;
return true;
}
// Start one past the last entry we stopped at.
if (args[stackStart + 1].Type == ObjType.Num)
{
if (args[stackStart + 1].Num < 0)
{
args[stackStart] = Obj.False;
return true;
}
int index = (int)args[stackStart + 1].Num;
if (index == args[stackStart + 1].Num)
{
args[stackStart] = index > map.Count() || map.Get(index) == Obj.Undefined ? Obj.False : new Obj(index + 1);
return true;
}
vm.Fiber.Error = Obj.MakeString("Iterator must be an integer.");
return false;
}
// If we're starting the iteration, start at the first used entry.
if (args[stackStart + 1] == Obj.Null)
{
args[stackStart] = new Obj(1);
return true;
}
vm.Fiber.Error = Obj.MakeString("Iterator must be a number.");
return false;
}
static bool prim_list_count(WrenVM vm, Obj[] args, int stackStart)
{
ObjList list = args[stackStart] as ObjList;
if (list != null)
{
args[stackStart] = new Obj(list.Count());
return true;
}
vm.Fiber.Error = Obj.MakeString("Trying to clear a non-list");
return false;
}
static bool prim_list_insert(WrenVM vm, Obj[] args, int stackStart)
{
ObjList list = (ObjList)args[stackStart];
if (args[stackStart + 1].Type == ObjType.Num)
{
int index = (int)args[stackStart + 1].Num;
if (args[stackStart + 1].Num == index)
{
if (index < 0)
index += list.Count() + 1;
if (index >= 0 && index <= list.Count())
{
list.Insert(args[stackStart + 2], index);
args[stackStart] = args[stackStart + 2];
return true;
}
vm.Fiber.Error = Obj.MakeString("Index out of bounds.");
return false;
}
// count + 1 here so you can "insert" at the very end.
vm.Fiber.Error = Obj.MakeString("Index must be an integer.");
return false;
}
vm.Fiber.Error = Obj.MakeString("Index must be a number.");
return false;
}
static bool prim_list_clear(WrenVM vm, Obj[] args, int stackStart)
{
ObjList list = args[stackStart] as ObjList;
if (list == null)
{
vm.Fiber.Error = Obj.MakeString("Trying to clear a non-list");
return false;
}
list.Clear();
args[stackStart] = Obj.Null;
return true;
}
static bool prim_list_add(WrenVM vm, Obj[] args, int stackStart)
{
ObjList list = args[stackStart] as ObjList;
if (list == null)
{
vm.Fiber.Error = Obj.MakeString("Trying to add to a non-list");
return false;
}
list.Add(args[stackStart + 1]);
args[stackStart] = args[stackStart + 1];
return true;
}
static bool prim_list_instantiate(WrenVM vm, Obj[] args, int stackStart)
{
args[stackStart] = new ObjList(16);
return true;
}
static bool prim_map_containsKey(WrenVM vm, Obj[] args, int stackStart)
{
ObjMap map = (ObjMap)args[stackStart];
if (ValidateKey(args[stackStart + 1]))
{
Obj v = map.Get(args[stackStart + 1]);
args[stackStart] = Obj.Bool(v != Obj.Undefined);
return true;
}
vm.Fiber.Error = Obj.MakeString("Key must be a value type or fiber.");
return false;
}
private ObjFiber LoadModule(Obj name, string source)
{
ObjModule module = GetModule(name);
// See if the module has already been loaded.
if (module == null)
{
module = new ObjModule(name as ObjString);
// Store it in the VM's module registry so we don't load the same module
// multiple times.
_modules.Set(name, module);
// Implicitly import the core module.
ObjModule coreModule = GetCoreModule();
foreach (ModuleVariable t in coreModule.Variables)
{
DefineVariable(module, t.Name, t.Container);
}
}
ObjFn fn = Compiler.Compile(this, module, name.ToString(), source, true);
if (fn == null)
{
// TODO: Should we still store the module even if it didn't compile?
return null;
}
ObjFiber moduleFiber = new ObjFiber(fn);
// Return the fiber that executes the module.
return moduleFiber;
}
static bool prim_map_count(WrenVM vm, Obj[] args, int stackStart)
{
ObjMap m = (ObjMap)args[stackStart];
args[stackStart] = new Obj(m.Count());
return true;
}
private bool ImportVariable(Obj moduleName, Obj variableName, out Obj result)
{
ObjModule module = GetModule(moduleName);
if (module == null)
{
result = Obj.MakeString("Could not load module");
return false; // Should only look up loaded modules
}
ObjString variable = variableName as ObjString;
if (variable == null)
{
result = Obj.MakeString("Variable name must be a string");
return false;
}
int variableEntry = module.Variables.FindIndex(v => v.Name == variable.ToString());
// It's a runtime error if the imported variable does not exist.
if (variableEntry == -1)
{
result = Obj.MakeString(string.Format("Could not find a variable named '{0}' in module '{1}'.", variableName, moduleName));
return false;
}
result = module.Variables[variableEntry].Container;
return true;
}
static bool prim_list_iterate(WrenVM vm, Obj[] args, int stackStart)
{
ObjList list = (ObjList)args[stackStart];
// If we're starting the iteration, return the first index.
if (args[stackStart + 1] == Obj.Null)
{
if (list.Count() != 0)
{
args[stackStart] = new Obj(0.0);
return true;
}
args[stackStart] = Obj.False;
return true;
}
if (args[stackStart + 1].Type == ObjType.Num)
{
int index = (int)args[stackStart + 1].Num;
if (args[stackStart + 1].Num == index)
{
if (!(index < 0) && !(index >= list.Count() - 1))
{
// Move to the next index.
args[stackStart] = new Obj(index + 1);
return true;
}
// Stop if we're out of bounds.
args[stackStart] = Obj.False;
return true;
}
vm.Fiber.Error = Obj.MakeString("Iterator must be an integer.");
return false;
}
vm.Fiber.Error = Obj.MakeString("Iterator must be a number.");
return false;
}
// Associates [key] with [value] in [map].
public void Set(Obj key, Obj c)
{
_entries[key] = c;
}
// Looks up the previously loaded module with [name].
// Returns null if no module with that name has been loaded.
private ObjModule GetModule(Obj name)
{
Obj moduleContainer = _modules.Get(name);
return moduleContainer == Obj.Undefined ? null : moduleContainer as ObjModule;
}
static bool prim_list_removeAt(WrenVM vm, Obj[] args, int stackStart)
{
ObjList list = (ObjList)args[stackStart];
if (args[stackStart + 1].Type == ObjType.Num)
{
int index = (int)args[stackStart + 1].Num;
if (args[stackStart + 1].Num == index)
{
if (index < 0)
index += list.Count();
if (index >= 0 && index < list.Count())
{
args[stackStart] = list.RemoveAt(index);
return true;
}
vm.Fiber.Error = Obj.MakeString("Index out of bounds.");
return false;
}
vm.Fiber.Error = Obj.MakeString("Index must be an integer.");
return false;
}
vm.Fiber.Error = Obj.MakeString("Index must be a number.");
return false;
}
private Obj ImportModule(Obj name)
{
// If the module is already loaded, we don't need to do anything.
if (_modules.Get(name) != Obj.Undefined) return Obj.Null;
// Load the module's source code from the embedder.
string source = LoadModuleFn(name.ToString());
if (source == null)
{
// Couldn't load the module.
return Obj.MakeString(string.Format("Could not find module '{0}'.", name));
}
ObjFiber moduleFiber = LoadModule(name, source);
// Return the fiber that executes the module.
return moduleFiber;
}
static bool prim_list_subscript(WrenVM vm, Obj[] args, int stackStart)
{
ObjList list = (ObjList)args[stackStart];
if (args[stackStart + 1].Type == ObjType.Num)
{
int index = (int)args[stackStart + 1].Num;
if (index == args[stackStart + 1].Num)
{
if (index < 0)
{
index += list.Count();
}
if (index >= 0 && index < list.Count())
{
args[stackStart] = list.Get(index);
return true;
}
vm.Fiber.Error = Obj.MakeString("Subscript out of bounds.");
return false;
}
vm.Fiber.Error = Obj.MakeString("Subscript must be an integer.");
return false;
}
ObjRange r = args[stackStart + 1] as ObjRange;
if (r == null)
{
vm.Fiber.Error = Obj.MakeString("Subscript must be a number or a range.");
return false;
}
// TODO: This is seriously broken and needs a rewrite
int from = (int)r.From;
if (from != r.From)
{
vm.Fiber.Error = Obj.MakeString("Range start must be an integer.");
return false;
}
int to = (int)r.To;
if (to != r.To)
{
vm.Fiber.Error = Obj.MakeString("Range end must be an integer.");
return false;
}
if (from < 0)
from += list.Count();
if (to < 0)
to += list.Count();
int step = to < from ? -1 : 1;
if (step > 0 && r.IsInclusive)
to += 1;
if (step < 0 && !r.IsInclusive)
to += 1;
// Handle copying an empty list
if (list.Count() == 0 && to == (r.IsInclusive ? -1 : 0))
{
to = 0;
step = 1;
}
int count = (to - from) * step + (step < 0 ? 1 : 0);
if (to < 0 || from + (count * step) > list.Count())
{
vm.Fiber.Error = Obj.MakeString("Range end out of bounds.");
return false;
}
if (from < 0 || (from >= list.Count() && from > 0))
{
vm.Fiber.Error = Obj.MakeString("Range start out of bounds.");
return false;
}
ObjList result = new ObjList(count);
for (int i = 0; i < count; i++)
{
result.Add(list.Get(from + (i * step)));
}
args[stackStart] = result;
return true;
}
// Verifies that [superclass] is a valid object to inherit from. That means it
// must be a class and cannot be the class of any built-in type.
//
// If successful, returns null. Otherwise, returns a string for the runtime
// error message.
private static Obj ValidateSuperclass(Obj name, Obj superclassContainer)
{
// Make sure the superclass is a class.
ObjClass superClass = superclassContainer as ObjClass;
if (superClass != null)
{
// Make sure it doesn't inherit from a sealed built-in type. Primitive methods
// on these classes assume the instance is one of the other Obj___ types and
// will fail horribly if it's actually an ObjInstance.
return superClass.IsSealed ? Obj.MakeString(string.Format("Class '{0}' cannot inherit from built-in class '{1}'.", name as ObjString, (superClass.Name))) : null;
}
return Obj.MakeString(string.Format("Class '{0}' cannot inherit from a non-class object.", name));
}
static bool prim_list_subscriptSetter(WrenVM vm, Obj[] args, int stackStart)
{
ObjList list = (ObjList)args[stackStart];
if (args[stackStart + 1].Type == ObjType.Num)
{
int index = (int)args[stackStart + 1].Num;
if (index == args[stackStart + 1].Num)
{
if (index < 0)
{
index += list.Count();
}
if (list != null && index >= 0 && index < list.Count())
{
list.Set(args[stackStart + 2], index);
args[stackStart] = args[stackStart + 2];
return true;
}
vm.Fiber.Error = Obj.MakeString("Subscript out of bounds.");
return false;
}
vm.Fiber.Error = Obj.MakeString("Subscript must be an integer.");
return false;
}
vm.Fiber.Error = Obj.MakeString("Subscript must be a number.");
return false;
}
internal int DefineVariable(ObjModule module, string name, Obj c)
{
if (module == null) module = GetCoreModule();
if (module.Variables.Count == ObjModule.MaxModuleVars) return -2;
// See if the variable is already explicitly or implicitly declared.
int symbol = module.Variables.FindIndex(m => m.Name == name);
if (symbol == -1)
{
// Brand new variable.
module.Variables.Add(new ModuleVariable { Name = name, Container = c });
symbol = module.Variables.Count - 1;
}
else if (module.Variables[symbol].Container == Obj.Undefined)
{
// Explicitly declaring an implicitly declared one. Mark it as defined.
module.Variables[symbol].Container = c;
}
else
{
// Already explicitly declared.
symbol = -1;
}
return symbol;
}
static bool prim_map_instantiate(WrenVM vm, Obj[] args, int stackStart)
{
args[stackStart] = new ObjMap();
return true;
}