Expression AssertBoolContext(Expression expression)
{
var type = GetExpressionType(expression);
if (TypeSystemServices.IsNumberOrBool(type) || type.IsEnum)
{
return(expression);
}
var op_Implicit = TypeSystemServices.FindImplicitConversionOperator(type, TypeSystemServices.BoolType);
if (op_Implicit != null)
{
//return [| $op_Implicit($expression) |]
return(CodeBuilder.CreateMethodInvocation(op_Implicit, expression));
}
// nullable types can be used in bool context
if (TypeSystemServices.IsNullable(type))
{
//return [| $(expression).HasValue |]
return(CodeBuilder.CreateMethodInvocation(expression, NameResolutionService.ResolveMethod(type, "get_HasValue")));
}
// string in a boolean context means string.IsNullOrEmpty (BOO-1035)
if (TypeSystemServices.StringType == type)
{
//return [| not string.IsNullOrEmpty($expression) |]
var notIsNullOrEmpty = new UnaryExpression(
UnaryOperatorType.LogicalNot,
CodeBuilder.CreateMethodInvocation(String_IsNullOrEmpty, expression));
BindExpressionType(notIsNullOrEmpty, TypeSystemServices.BoolType);
return(notIsNullOrEmpty);
}
// reference types can be used in bool context
if (!type.IsValueType)
{
return(expression);
}
Error(CompilerErrorFactory.BoolExpressionRequired(expression, type.ToString()));
return(expression);
}