private BoundExpression BindExpression(ExpressionSyntax syntax, Type type)
{
var result = BindExpression(syntax);
if (result.Type != type)
{
_diagnostics.ReportCannotConvert(syntax.Span, result.Type, type);
}
return(result);
}
private BoundExpression BindExpression(ExpressionSyntax syntax, TypeSymbol expectedType)
{
var expression = BindExpression(syntax);
if (expectedType != TypeSymbol.Error && expression.Type != TypeSymbol.Error && expression.Type != expectedType)
{
_diagnostics.ReportCannotConvert(syntax.Span, expression.Type, expectedType);
}
return(expression);
}
private BoundExpression BindExpression(ExpressionSyntax syntax, TypeSymbol targetType)
{
var result = BindExpression(syntax);
if (targetType != TypeSymbol.Error &&
result.Type != TypeSymbol.Error &&
result.Type != targetType)
{
diagnostics.ReportCannotConvert(syntax.Span, result.Type, targetType);
}
return(result);
}
private BoundExpression BindConversion(TextSpan diagnosticSpan, BoundExpression expression, TypeSymbol type, bool allowExplicit = false)
{
var conversion = Conversion.Classify(expression.Type, type);
if (!conversion.Exists)
{
if (expression.Type != TypeSymbol.Error && type != TypeSymbol.Error)
{
_diagnostics.ReportCannotConvert(diagnosticSpan, expression.Type, type);
}
return(new BoundErrorExpression());
}
if (!allowExplicit && conversion.IsExplicit)
{
_diagnostics.ReportCannotConvertImplicitly(diagnosticSpan, expression.Type, type);
}
if (conversion.IsIdentity)
{
return(expression);
}
return(new BoundConversionExpression(type, expression));
}
private BoundExpression BindAssignmentExpression(AssignmentExpressionSyntax syntax)
{
var name = syntax.IdentifierToken.Text;
var boundExpression = BindExpression(syntax.Expression);
if (!_scope.TryLookup(name, out var variable))
{
_diagnostics.ReportUndefinedName(syntax.IdentifierToken.Span, name);
return(boundExpression);
}
if (variable.IsReadOnly)
{
_diagnostics.ReportCannotAssign(syntax.EqualsToken.Span, name);
}
if (boundExpression.Type != variable.Type)
{
_diagnostics.ReportCannotConvert(syntax.Expression.Span, boundExpression.Type, variable.Type);
return(boundExpression);
}
return(new BoundAssignmentExpression(variable, boundExpression));
}
