private void AssignInferredType(AstExpressionOperand operand, AstTypeDefinition typeDef)
{
var typeRef = AstTypeReferenceType.From(typeDef);
typeRef.IsInferred = true;
SymbolTable !.Add(typeRef);
operand.SetTypeReference(typeRef);
}
public override void VisitAssignment(AstAssignment assign)
{
Ast.Guard(assign.HasVariable, "AstVariable not set on assign.");
assign.VisitChildren(this);
if (assign.Variable is AstVariableReference varRef &&
varRef.VariableDefinition is null)
{
var symbol = varRef.Symbol;
AstTypeReference?typeRef = null;
// Variable.TypeReference is usually null.
if (varRef.HasTypeReference)
{
typeRef = varRef.TypeReference.MakeCopy();
}
// It is set only when type is explicitly in source code, or has been inferred.
var varDef = new AstVariableDefinition(typeRef);
varDef.SetIdentifier(varRef.Identifier);
varDef.SetSymbol(symbol);
symbol.RemoveReference(varRef);
AstSymbolReferenceRemover.RemoveReference(varRef);
symbol.AddNode(varDef);
assign.SetVariableDefinition(varDef);
// do the children again for types
assign.VisitChildren(this);
}
if (!assign.Variable !.HasTypeReference)
{
// typeless assign of var (x = 42)
var expr = assign.Expression;
var typeRef = expr.TypeReference;
Ast.Guard(typeRef.HasIdentifier, "AstIdentifier not set on AstTypeReference.");
var symbol = assign.Variable.Symbol;
var def = symbol.DefinitionAs <AstTypeDefinition>();
if (def is not null)
{
typeRef = AstTypeReferenceType.From(def);
assign.Variable.SetTypeReference(typeRef);
}
else
{
assign.Variable.SetTypeReference(typeRef.MakeCopy());
}
Visit(assign.Variable.TypeReference);
}
}