Does Linqpad have support for truncating numeric fields to a maximum number of decimal places similar to the "Results" configuration settings that apply to DateTime output:

Assuming Linqpad doesn't have built in support (no option in the Results settings tab), are there any other options? I have an on object with over hundreds of double properties and I'm trying to avoid writing Math.Round(obj.Property, 4, MidpointRound.ToZero) 200 times.

CodePudding user response：

With Linqpad 7 you can customise the dump command by adding this to your query.

static object ToDump(object o)
{
    if (o is double d) return Math.Round(d, 4, MidpointRounding.ToZero);
    return o;
}

Example

void Main()
{
    Single s = 1.2345678f;
    Double d = (double) s;
    (new { s, d }).Dump();
}

By default this gives

but with the customised Dump it gives

See

//supports any collection inheriting from IEnumerable<T>
var myEnumerable = new List<MyObject>();

//set precision and MidpointRounding if desired
myEnumerable.NumericTruncate(4, MidpointRounding.ToZero).Dump();

//set precision with natural rounding
myEnumerable.NumericTruncate(4).Dump();

NumericFormat()

This method output string values formatted with consistent lenghth.

//supports any collection inheriting from IEnumerable<T>
var myEnumerable = new List<MyObject>();

//set precision and MidpointRounding if desired
myEnumerable.NumericFormat(4, MidpointRounding.ToZero).Dump();

//set precision with natural rounding
myEnumerable.NumericFormat(4).Dump();

MyExtensions Methods

Paste the code below into your MyExtentions file in Linqpad:

public static IEnumerable<ExpandoObject> NumericTruncate<T>(this IEnumerable<T> values, 
     int precision, MidpointRounding? round = null)
{
    var itemType = typeof(T);
    var valArr = values.ToArray();
    var types = new HashSet<Type>() { typeof(decimal), typeof(double), typeof(float) };
    var typesNullable = new HashSet<Type>() { typeof(decimal?), typeof(double?), typeof(float?) };

    var props = itemType.GetProperties(BindingFlags.Public | BindingFlags.Instance);

    for (int i = 0; i < valArr.Length; i  )
    {
        IDictionary<string, object> obj = new System.Dynamic.ExpandoObject();
        foreach (var prop in props)
        {
            var val = prop.GetValue(valArr[i]);
            if (types.Contains(prop.PropertyType))
            {
                obj[prop.Name] = round.HasValue
                    ? Math.Round(Convert.ToDouble(val), precision, round.Value)
                    : Math.Round(Convert.ToDouble(val), precision);
            }
            else if (typesNullable.Contains(prop.PropertyType))
            {
                var valNull = (double?)val;
                if (valNull.HasValue)
                    obj[prop.Name] = round.HasValue
                        ? Math.Round(Convert.ToDouble(valNull.Value), precision, round.Value)
                        : Math.Round(Convert.ToDouble(valNull.Value), precision);
                else
                    obj[prop.Name] = null;
            }
            else
                obj[prop.Name] = val;
        }
        yield return (ExpandoObject) obj;
    }
}
public static IEnumerable<ExpandoObject> NumericFormat<T>(this IEnumerable<T> values,
    int precision = 4, MidpointRounding? round = null)
{
    var itemType = typeof(T);
    var valArr = values.ToArray();
    var types = new HashSet<Type>() { typeof(decimal), typeof(double), typeof(float) };
    var typesNullable = new HashSet<Type>() { typeof(decimal?), typeof(double?), typeof(float?) };
    var pattern = "#,##0."   string.Concat(Enumerable.Range(1, precision).Select(h=> "0"));

    var props = itemType.GetProperties(BindingFlags.Public | BindingFlags.Instance);

    for (int i = 0; i < valArr.Length; i  )
    {
        IDictionary<string, object> obj = new System.Dynamic.ExpandoObject();
        foreach (var prop in props)
        {
            var val = prop.GetValue(valArr[i]);
            if (types.Contains(prop.PropertyType))
            {
                obj[prop.Name] = round.HasValue
                    ? Math.Round(Convert.ToDouble(val), precision, round.Value).ToString(pattern)
                    : Math.Round(Convert.ToDouble(val), precision).ToString(pattern);
            }
            else if (typesNullable.Contains(prop.PropertyType))
            {
                var valNull = (double?)val;
                if (valNull.HasValue)
                    obj[prop.Name] = round.HasValue
                        ? Math.Round(Convert.ToDouble(valNull.Value), precision, round.Value).ToString(pattern)
                        : Math.Round(Convert.ToDouble(valNull.Value), precision).ToString(pattern);
                else
                    obj[prop.Name] = null;
            }
            else
                obj[prop.Name] = val;
        }
        yield return (ExpandoObject)obj;
    }
}