Michael Schimmel
124 lines
3.4 KiB
ObjectPascal
124 lines
3.4 KiB
ObjectPascal
unit Myc.Ast.Scope;
|
|
|
|
interface
|
|
|
|
uses
|
|
System.SysUtils,
|
|
System.Generics.Collections,
|
|
System.Classes,
|
|
Myc.Ast.Nodes;
|
|
|
|
type
|
|
T_ExecutionScope = class(TInterfacedObject, IExecutionScope)
|
|
private
|
|
FParent: IExecutionScope;
|
|
FVariables: TDictionary<string, TAstValue>;
|
|
procedure DumpScope(const ABuilder: TStringBuilder; AIndent: Integer);
|
|
protected
|
|
// IExecutionScope
|
|
function GetParent: IExecutionScope;
|
|
procedure Clear;
|
|
function FindValue(const Name: string; out Value: TAstValue): Boolean;
|
|
procedure SetValue(const Name: string; const Value: TAstValue);
|
|
procedure AssignValue(const Name: string; const Value: TAstValue);
|
|
function Dump: string;
|
|
public
|
|
constructor Create(AParent: IExecutionScope = nil);
|
|
destructor Destroy; override;
|
|
end;
|
|
|
|
implementation
|
|
|
|
{ T_ExecutionScope }
|
|
|
|
constructor T_ExecutionScope.Create(AParent: IExecutionScope);
|
|
begin
|
|
inherited Create;
|
|
FParent := AParent;
|
|
FVariables := TDictionary<string, TAstValue>.Create;
|
|
end;
|
|
|
|
destructor T_ExecutionScope.Destroy;
|
|
begin
|
|
FVariables.Free;
|
|
inherited Destroy;
|
|
end;
|
|
|
|
function T_ExecutionScope.GetParent: IExecutionScope;
|
|
begin
|
|
Result := FParent;
|
|
end;
|
|
|
|
procedure T_ExecutionScope.AssignValue(const Name: string; const Value: TAstValue);
|
|
begin
|
|
if FVariables.ContainsKey(Name) then
|
|
FVariables.AddOrSetValue(Name, Value)
|
|
else if Assigned(FParent) then
|
|
FParent.AssignValue(Name, Value)
|
|
else
|
|
raise Exception.CreateFmt('Cannot assign to undeclared variable "%s".', [Name]);
|
|
end;
|
|
|
|
procedure T_ExecutionScope.Clear;
|
|
begin
|
|
FVariables.Clear;
|
|
if Assigned(FParent) then
|
|
FParent.Clear;
|
|
end;
|
|
|
|
procedure T_ExecutionScope.DumpScope(const ABuilder: TStringBuilder; AIndent: Integer);
|
|
var
|
|
pair: TPair<string, TAstValue>;
|
|
indentStr: string;
|
|
begin
|
|
indentStr := ''.PadLeft(AIndent);
|
|
if (FVariables.Count > 0) then
|
|
begin
|
|
for pair in FVariables do
|
|
ABuilder.AppendLine(indentStr + Format(' %s: %s', [pair.Key, pair.Value.ToString]));
|
|
end
|
|
else
|
|
begin
|
|
ABuilder.AppendLine(indentStr + ' (empty)');
|
|
end;
|
|
|
|
if Assigned(FParent) then
|
|
begin
|
|
ABuilder.AppendLine(indentStr + '[Parent Scope]');
|
|
// As FParent is now an interface, we must cast it back to the class to call the private DumpScope.
|
|
// This indicates that DumpScope should perhaps be part of the interface or handled differently.
|
|
// For now, we use a cast to keep the functionality.
|
|
(FParent as T_ExecutionScope).DumpScope(ABuilder, AIndent + 2);
|
|
end;
|
|
end;
|
|
|
|
function T_ExecutionScope.Dump: string;
|
|
var
|
|
builder: TStringBuilder;
|
|
begin
|
|
builder := TStringBuilder.Create;
|
|
try
|
|
builder.AppendLine('[Current Scope]');
|
|
DumpScope(builder, 0);
|
|
Result := builder.ToString.TrimRight;
|
|
finally
|
|
builder.Free;
|
|
end;
|
|
end;
|
|
|
|
function T_ExecutionScope.FindValue(const Name: string; out Value: TAstValue): Boolean;
|
|
begin
|
|
Result := FVariables.TryGetValue(Name, Value);
|
|
if not Result and Assigned(FParent) then
|
|
begin
|
|
Result := FParent.FindValue(Name, Value);
|
|
end;
|
|
end;
|
|
|
|
procedure T_ExecutionScope.SetValue(const Name: string; const Value: TAstValue);
|
|
begin
|
|
FVariables.AddOrSetValue(Name, Value);
|
|
end;
|
|
|
|
end.
|