Contains various parser optimized for speed and no allocation. This package was built from the source at https://github.com/nemesissoft/Nemesis.TextParsers/tree/519299603ad55cff1d7a52e9db77969aff95f2bf
$ dotnet add package Nemesis.TextParsers
Nemesis.TextParsers
TL;DR - are you looking for performant, non allocating serializer from structural object to flat, human editable string? Look no further. Benchmarks shows potential gains from using Nemesis.TextParsers
| Method | Count | Mean | Ratio | Allocated |
|---|---|---|---|---|
| TextJson | 10 | 121.02 us | 1.00 | 35200 B |
| TextJsonBytes | 10 | 120.79 us | 1.00 | 30400 B |
| TextJsonNet | 10 | 137.28 us | 1.13 | 288000 B |
| TextParsers | 10 | 49.02 us | 0.41 | 6400 B |
| TextJson | 100 | 846.06 us | 1.00 | 195200 B |
| TextJsonBytes | 100 | 845.84 us | 1.00 | 163200 B |
| TextJsonNet | 100 | 943.71 us | 1.12 | 636800 B |
| TextParsers | 100 | 463.33 us | 0.55 | 42400 B |
| TextJson | 1000 | 8,142.13 us | 1.00 | 1639200 B |
| TextJsonBytes | 1000 | 8,155.41 us | 1.00 | 1247200 B |
| TextJsonNet | 1000 | 8,708.12 us | 1.07 | 3880800 B |
| TextParsers | 1000 | 4,384.00 us | 0.54 | 402400 B |
More comprehensive examples are here
When stucked with a task of parsing various items form strings we often opt for TypeConverter. We tend to create methods like:
public static T FromString<T>(string text) =>
(T)TypeDescriptor.GetConverter(typeof(T))
.ConvertFromInvariantString(text);or even create similar constructs to be in line with object oriented design:
public abstract class TextTypeConverter : TypeConverter
{
public sealed override bool CanConvertFrom(ITypeDescriptorContext context, Type sourceType) =>
sourceType == typeof(string) || base.CanConvertFrom(context, sourceType);
public sealed override bool CanConvertTo(ITypeDescriptorContext context, Type destinationType) =>
destinationType == typeof(string) || base.CanConvertTo(context, destinationType);
}
public abstract class BaseTextConverter<TValue> : TextTypeConverter
{
public sealed override object ConvertFrom(ITypeDescriptorContext context, CultureInfo culture, object value) =>
value is string text ? ParseString(text) : default;
public abstract TValue ParseString(string text);
public sealed override object ConvertTo(ITypeDescriptorContext context, CultureInfo culture, object value, Type destinationType) =>
destinationType == typeof(string) ?
FormatToString((TValue)value) :
base.ConvertTo(context, culture, value, destinationType);
public abstract string FormatToString(TValue value);
}What is wrong with that? Well, nothing... except of performance and possibly - support for generics.
TypeConverter was designed around 2002 when processing power tended to double every now and then and (in my opinion) it was more suited for creating GUI-like editors where performance usually is not an issue. But imagine a service application like exchange trading suite that has to perform multiple operations per second and in such cases processor has more important thing to do than parsing strings.
| Method | Mean | Ratio | Gen 0 | Gen 1 | Allocated | Remarks |
|---|---|---|---|---|---|---|
| RegEx parsing | 4,528.99 us | 44.98 | 492.1875 | - | 2089896 B | Regular expression with escaping support |
| StringSplitTest_KnownType | 93.41 us | 0.92 | 9.5215 | 0.1221 | 40032 B | string.Split(..).Select(text=>int.Parse(text)) |
| StringSplitTest_DynamicType | 474.73 us | 4.69 | 24.4141 | - | 104032 B | string.Split + TypeDescriptor.GetConverter |
| SpanSplitTest_NoAlloc | 101.00 us | 1.00 | - | - | - | "1|2|3".AsSpan().Tokenize() |
| SpanSplitTest_Alloc | 101.38 us | 1.00 | 0.8545 | - | 4024 B | "1|2|3".AsSpan().Tokenize(); var array = new int[1000]; |
var avg = "1|2|3".AsSpan()
.Tokenize('|', '\\', true)
.Parse('\\', '∅', '|')
.Average(DoubleTransformer.Instance);Span<char> initialBuffer = stackalloc char[32];
using var accumulator = new ValueSequenceBuilder<char>initialBuffer);
using (var enumerator = coll.GetEnumerator())
while (enumerator.MoveNext())
FormatElement(formatter, enumerator.Current, ref accumulator);
return accumulator.AsSpanTo(accumulator.Length > 0 ? accumulator.Length - 1 : 0).ToString();Open source software is free to use but creating and maintaining is a laborious effort. Should you wish to support us in our noble endeavour, please consider the following donation methods:
If you just want to say thanks, you can buy me a ☕ or ⭐ any of my repositories.
