//Returns a variable from a local scope marked with NoInit flag
//If such variable couldn't be found returns -1
private ScopeVar GetNoInitVariable(ElaEquation s, out string name)
{
ScopeVar var;
name = s.Left.GetName();
if (s.IsFunction())
{
name = s.GetFunctionName();
}
if (CurrentScope.Locals.TryGetValue(name, out var))
{
//If it doesn't have a NoInit flag we are not good
if ((var.Flags & ElaVariableFlags.NoInit) != ElaVariableFlags.NoInit)
{
return(ScopeVar.Empty);
}
else
{
var.Address = 0 | var.Address << 8; //Aligning it to local scope
return(var);
}
}
return(ScopeVar.Empty);
}
//Adds a variable with NoInit flag to the current scope
//This method also calculates additional flags and metadata for variables.
//If a given binding if defined by pattern matching then all variables from
//patterns are traversed using AddPatternVariable method.
private bool AddNoInitVariable(ElaEquation exp)
{
var flags = exp.VariableFlags | ElaVariableFlags.NoInit;
//This binding is not defined by PM
if (exp.IsFunction())
{
var name = exp.GetFunctionName();
if (name == null || Char.IsUpper(name[0]))
{
AddError(ElaCompilerError.InvalidFunctionDeclaration, exp, FormatNode(exp.Left));
return(false);
}
AddVariable(name, exp.Left, flags | ElaVariableFlags.Function, exp.GetArgumentNumber());
}
else if (exp.Left.Type == ElaNodeType.NameReference && !((ElaNameReference)exp.Left).Uppercase)
{
var data = -1;
if (exp.Right.Type == ElaNodeType.Builtin)
{
//Adding required hints for a built-in
data = (Int32)((ElaBuiltin)exp.Right).Kind;
flags |= ElaVariableFlags.Builtin;
}
else if (exp.Right.Type == ElaNodeType.Lambda)
{
var fun = (ElaLambda)exp.Right;
flags |= ElaVariableFlags.Function;
data = fun.GetParameterCount();
}
else if (exp.Right.IsLiteral())
{
flags |= ElaVariableFlags.ObjectLiteral;
}
AddVariable(exp.Left.GetName(), exp, flags, data);
}
else
{
AddPatternVariables(exp.Left);
}
return(true);
}
//Compile an instance member. Argument classPrefix (module alias) is null if a class is
//not prefixed, otherwise it should be used to lookup class members.
private void CompileInstanceMember(string className, string classPrefix, ElaEquation s, LabelMap map,
string currentTypePrefix, string currentType)
{
//Obtain a 'table' function of a class
var name = s.GetLeftName();
var btVar = ObtainClassFunction(classPrefix, className, name, s.Line, s.Column);
if (btVar.IsEmpty())
{
AddError(ElaCompilerError.MemberInvalid, s, name, className);
}
var builtin = (btVar.Flags & ElaVariableFlags.Builtin) == ElaVariableFlags.Builtin;
var args = 0;
//Here we need to understand how many arguments a class function has.
//If our declaration has less arguments (allowed by Ela) we need to do
//eta expansion.
if (builtin)
{
args = BuiltinParams((ElaBuiltinKind)btVar.Data);
}
else
{
args = btVar.Data;
}
//First we check if this binding is simply a function reference
if (!TryResolveInstanceBinding(args, s.Right, map))
{
//Eta expansion should be done if a member is not a function literal
//(it can be a partially applied function) or if a number of arguments
//doesn't match.
if (!s.IsFunction())
{
EtaExpand(null, s.Right, map, args);
}
else if (s.GetArgumentNumber() < args)
{
EtaExpand(null, s, map, args);
}
else
{
CompileFunction(s, map);
}
}
AddLinePragma(s);
//It is possible if we are compiling a default instance (that can be
//used to automatically generate instances).
if (currentType != null)
{
//Depending whether this is a built-in class or a different approach is
//used to add a member function.
if (!builtin)
{
PushVar(btVar);
}
else
{
cw.Emit(Op.PushI4, (Int32)btVar.Data);
}
//We need to obtain a 'real' global ID of the type that we are extending. This
//is done using this helper method.
EmitSpecName(currentTypePrefix, "$$" + currentType, s, ElaCompilerError.UndefinedType);
//Finally adding a member function.
cw.Emit(Op.Addmbr);
}
else
{
var nm = "$default$" + name;
//We are double binding the same default member which is not allowed within
//the same module.
if (globalScope.Locals.ContainsKey(nm))
{
AddError(ElaCompilerError.DefaultMemberAlreadyExist, s, name, className);
globalScope.Locals.Remove(name);
}
var flags = ElaVariableFlags.None;
var data = -1;
if (s.Right.Type == ElaNodeType.Builtin)
{
flags = ElaVariableFlags.Builtin;
data = (Int32)((ElaBuiltin)s.Right).Kind;
}
var dv = AddVariable(nm, s, flags, data);
PopVar(dv);
}
}
//Compile all declarations including function bindings, name bindings and bindings
//defined by pattern matching.
private void CompileDeclaration(ElaEquation s, LabelMap map, Hints hints)
{
//Check for some errors
ValidateBinding(s);
var partial = (s.VariableFlags & ElaVariableFlags.PartiallyApplied) == ElaVariableFlags.PartiallyApplied;
var fun = partial || s.IsFunction();
if ((s.Left.Type != ElaNodeType.NameReference || ((ElaNameReference)s.Left).Uppercase) && !fun)
{
if ((hints & Hints.Lazy) == Hints.Lazy)
{
CompileLazyBindingPattern(s, map);
}
else
{
CompileBindingPattern(s, map);
}
}
else
{
var nm = default(String);
var sv = GetNoInitVariable(s, out nm);
var addr = sv.Address;
if (sv.IsEmpty())
{
addr = AddVariable(s.Left.GetName(), s, s.VariableFlags, -1);
}
else
{
CurrentScope.AddFlags(nm, ElaVariableFlags.Self);
}
//Compile expression and write it to a variable
if (fun)
{
//*****CURRENTLY NOT USED!
//Here we automatically eta expand functions defined through partial application
if (partial)
{
EtaExpand(s.Left.GetName(), s.Right, map, s.Arguments);
}
else if (CompileFunction(s, map))
{
CurrentScope.AddFlags(nm, ElaVariableFlags.Clean); //A function is clean
}
}
else
{
map.BindingName = s.Left.GetName();
if ((hints & Hints.Lazy) == Hints.Lazy)
{
CompileLazyExpression(s.Right, map, Hints.None);
}
else
{
var ed = CompileExpression(s.Right, map, Hints.None, s);
if (ed.Type == DataKind.Builtin)
{
CurrentScope.AddFlagsAndData(nm, ElaVariableFlags.Builtin, ed.Data);
}
}
}
//Now, when done initialization, when can remove NoInit flags.
if (!sv.IsEmpty())
{
CurrentScope.RemoveFlags(nm, ElaVariableFlags.NoInit | ElaVariableFlags.Self);
}
AddLinePragma(s);
PopVar(addr);
}
}
//**********************************TEMPORARY DISABLED
//This method checks if a given expression is a regular function definition or a function
//defined through partial application of another function.
private bool IsFunction(ElaEquation eq)
{
//A simple case - regular function definition
if (eq.IsFunction())
return true;
//This may be a function defined through partial application. Here we only
//recognize two cases - when the head is an ordinary identifier and if a head is
//a fully qualified name.
if (eq.Right != null && eq.Right.Type == ElaNodeType.Juxtaposition)
{
var jx = (ElaJuxtaposition)eq.Right;
//A head is an identifier
if (jx.Target.Type == ElaNodeType.NameReference)
{
var sv = GetVariable(jx.Target.GetName(), CurrentScope, GetFlags.NoError, 0, 0);
//This is a partially applied function, therefore we can "count" this as a function.
return IfFunction(eq, sv, jx.Parameters.Count, false);
}
else if (jx.Target.Type == ElaNodeType.FieldReference) //This might be a fully qualified name
{
var tr = (ElaFieldReference)jx.Target;
//A target can only be a name reference; otherwise we don't see it as a function.
if (tr.TargetObject.Type == ElaNodeType.NameReference)
{
CodeFrame _;
var sv = FindByPrefix(tr.TargetObject.GetName(), tr.FieldName, out _);
return IfFunction(eq, sv, jx.Parameters.Count, false);
}
}
}
else if (eq.Right != null && eq.Right.Type == ElaNodeType.NameReference)
{
//This may be a function defined as an alias for another function.
var sv = GetVariable(eq.Right.GetName(), CurrentScope, GetFlags.NoError, 0, 0);
//This is an alias, we can "count" this as a function.
return IfFunction(eq, sv, 0, true);
}
return false;
}
//Compile an instance member. Argument classPrefix (module alias) is null if a class is
//not prefixed, otherwise it should be used to lookup class members.
private void CompileInstanceMember(string className, string classPrefix, ElaEquation s, LabelMap map,
string currentTypePrefix, string currentType)
{
//Obtain a 'table' function of a class
var name = s.GetLeftName();
var btVar = ObtainClassFunction(classPrefix, className, name, s.Line, s.Column);
if (btVar.IsEmpty())
AddError(ElaCompilerError.MemberInvalid, s, name, className);
var builtin = (btVar.Flags & ElaVariableFlags.Builtin) == ElaVariableFlags.Builtin;
var args = 0;
//Here we need to understand how many arguments a class function has.
//If our declaration has less arguments (allowed by Ela) we need to do
//eta expansion.
if (builtin)
args = BuiltinParams((ElaBuiltinKind)btVar.Data);
else
args = btVar.Data;
//First we check if this binding is simply a function reference
if (!TryResolveInstanceBinding(args, s.Right, map))
{
//Eta expansion should be done if a member is not a function literal
//(it can be a partially applied function) or if a number of arguments
//doesn't match.
if (!s.IsFunction())
EtaExpand(null, s.Right, map, args);
else if (s.GetArgumentNumber() < args)
EtaExpand(null, s, map, args);
else
CompileFunction(s);
}
AddLinePragma(s);
//It is possible if we are compiling a default instance (that can be
//used to automatically generate instances).
if (currentType != null)
{
//Depending whether this is a built-in class or a different approach is
//used to add a member function.
if (!builtin)
PushVar(btVar);
else
cw.Emit(Op.PushI4, (Int32)btVar.Data);
//We need to obtain a 'real' global ID of the type that we are extending. This
//is done using this helper method.
EmitSpecName(currentTypePrefix, "$$" + currentType, s, ElaCompilerError.UndefinedType);
//Finally adding a member function.
cw.Emit(Op.Addmbr);
}
else
{
var nm = "$default$" + name;
//We are double binding the same default member which is not allowed within
//the same module.
if (globalScope.Locals.ContainsKey(nm))
{
AddError(ElaCompilerError.DefaultMemberAlreadyExist, s, name, className);
globalScope.Locals.Remove(name);
}
var flags = ElaVariableFlags.None;
var data = -1;
if (s.Right.Type == ElaNodeType.Builtin)
{
flags = ElaVariableFlags.Builtin;
data = (Int32)((ElaBuiltin)s.Right).Kind;
}
var dv = AddVariable(nm, s, flags, data);
PopVar(dv);
}
}