protected static Expression GetConversion(
Expression sourceValue,
Type targetType,
MethodInfo tryParseMethod,
ParameterExpression valueVariable)
{
if (sourceValue.Type != typeof(string))
{
sourceValue = ToStringConverter.GetConversion(sourceValue);
}
var tryParseCall = Expression.Call(tryParseMethod, sourceValue, valueVariable);
var successfulParseReturnValue = valueVariable.GetConversionTo(targetType);
var defaultValue = targetType.ToDefaultExpression();
var parsedValueOrDefault = Expression.Condition(tryParseCall, successfulParseReturnValue, defaultValue);
var tryParseBlock = Expression.Block(new[] { valueVariable }, parsedValueOrDefault);
return(tryParseBlock);
}
public override Expression GetConversion(Expression sourceValue, Type targetType)
{
if (sourceValue.Type == _nullableTargetType)
{
return(sourceValue.GetValueOrDefaultCall());
}
if (sourceValue.Type != typeof(string))
{
sourceValue = _toStringConverter.GetConversion(sourceValue);
}
var tryParseCall = Expression.Call(_tryParseMethod, sourceValue, _valueVariable);
var successfulParseReturnValue = _valueVariable.GetConversionTo(targetType);
var defaultValue = Expression.Default(targetType);
var parsedValueOrDefault = Expression.Condition(tryParseCall, successfulParseReturnValue, defaultValue);
var tryParseBlock = Expression.Block(new[] { _valueVariable }, parsedValueOrDefault);
return(tryParseBlock);
}
private static Expression GetNumericToFlagsEnumConversion(
Expression sourceValue,
Expression fallbackValue,
Type nonNullableTargetEnumType,
string enumTypeName,
ParameterExpression enumValueVariable,
Expression assignEnumValue)
{
var underlyingEnumType = enumValueVariable.Type;
var sourceValueVariable = Expression.Variable(underlyingEnumType, enumTypeName + "Source");
if (sourceValue.Type != underlyingEnumType)
{
sourceValue = Expression.Convert(sourceValue, underlyingEnumType);
}
var assignSourceVariable = sourceValueVariable.AssignTo(sourceValue);
var populationLoop = GetNumericToFlagsEnumPopulationLoop(
nonNullableTargetEnumType,
enumTypeName,
enumValueVariable,
sourceValueVariable,
out var enumValuesVariable,
out var assignEnumValues);
var populationBlock = Expression.Block(
new[] { sourceValueVariable, enumValueVariable, enumValuesVariable },
assignSourceVariable,
assignEnumValue,
assignEnumValues,
populationLoop,
enumValueVariable.GetConversionTo(fallbackValue.Type));
return(populationBlock);
}