public static LinkedListNode<Lexeme> TryParse(LinkedListNode<Lexeme> lexemes, out Node resultNode)
{
resultNode = null;
var nextLexeme = StructDecl.TryParse(lexemes, out StructDecl structDecl);
if (structDecl != null)
{
resultNode = structDecl;
return nextLexeme;
}
nextLexeme = FnDecl.TryParse(lexemes, out FnDecl fn);
if (fn != null)
{
resultNode = fn;
return nextLexeme;
}
nextLexeme = Stmt.TryParseStruct(lexemes, out Stmt stmt);
if (stmt != null)
{
resultNode = stmt;
return nextLexeme;
}
return lexemes;
}
public override void ResolveNames(Scope scope, ErrorHandler errorHandler)
{
Value?.ResolveNames(scope, errorHandler);
FnDecl target = scope.FindFn();
if (target == null)
{
errorHandler.AddMessage(Severity.Error, $"return statement is not inside a function", Token);
}
TargetFn = target;
}
public override void CheckTypes(ErrorHandler errorHandler)
{
if (TargetNode != null)
{
return;
}
var viableCandidates = new List <FnDecl>();
var args = Args.ToList();
foreach (var decl in TargetNodeCandidates)
{
var parameters = decl.Parameters.ToList();
if (parameters.Count != args.Count)
{
continue;
}
bool success = false;
for (int i = 0; i < parameters.Count; i++)
{
if (!args[i].CanConvertTo(parameters[i].Type, errorHandler))
{
break;
}
success = true;
}
if (!success)
{
continue;
}
viableCandidates.Add(decl);
}
if (viableCandidates.Count == 0)
{
errorHandler.AddMessage(Severity.Error, $"No overload of function {Token.Value} with matching parameters found", Token);
}
else if (viableCandidates.Count > 1)
{
errorHandler.AddMessage(Severity.Error, $"Multiple overloads of function {Token.Value} with the same parameter types found", Token);
}
else
{
TargetNode = viableCandidates[0];
}
}
public static LinkedListNode <Lexeme> TryParse(LinkedListNode <Lexeme> lexemes, out FnDecl resultNode)
{
resultNode = null;
var nextLexeme = Type.TryParse(lexemes, out Type type);
if (type == null)
{
return(lexemes);
}
if (nextLexeme.Value.Type != LT.IDENT)
{
return(lexemes);
}
Lexeme token = nextLexeme.Value;
nextLexeme = nextLexeme.Next;
if (nextLexeme.Value.Type != LT.OP_PAREN_O)
{
return(lexemes);
}
nextLexeme = nextLexeme.Next;
List <FnParam> fnParams = new List <FnParam>();
nextLexeme = FnParam.TryParse(nextLexeme, out FnParam arg);
if (arg != null)
{
fnParams.Add(arg);
while (nextLexeme.Value.Type == LT.OP_COMMA)
{
nextLexeme = nextLexeme.Next;
nextLexeme = FnParam.TryParse(nextLexeme, out arg);
if (arg == null)
{
throw new Exception($"Trailing comma in argument list at {nextLexeme.Value.File}:{nextLexeme.Value.Line}");
}
fnParams.Add(arg);
}
}
if (nextLexeme.Value.Type != LT.OP_PAREN_C)
{
throw new Exception($"Missing closing parenthesis in function definition at {nextLexeme.Value.File}:{nextLexeme.Value.Line}");
}
nextLexeme = nextLexeme.Next;
if (nextLexeme.Value.Type != LT.OP_BRACE_O)
{
throw new Exception($"Cannot find function body opening brace at {nextLexeme.Value.File}:{nextLexeme.Value.Line}");
}
nextLexeme = nextLexeme.Next;
List <Stmt> stmts = new List <Stmt>();
nextLexeme = Stmt.TryParse(nextLexeme, out Stmt stmt);
while (stmt != null)
{
stmts.Add(stmt);
nextLexeme = Stmt.TryParse(nextLexeme, out stmt);
}
if (nextLexeme.Value.Type != LT.OP_BRACE_C)
{
throw new Exception($"Missing closing brace for function body at {nextLexeme.Value.File}:{nextLexeme.Value.Line}");
}
nextLexeme = nextLexeme.Next;
resultNode = new FnDecl {
Type = type, Parameters = fnParams, Body = new BlockBody(stmts), Token = token
};
return(nextLexeme);
}
