Sprog

Sprog (Danish for 'Language') cross-platform string parsing library written for C# 7+ and .NET Core.

Usage

Parsing a simple identifier

Parser TakeIdentifier(string input, out string _id) =>
    new Parser(input)
        .Skip(IsWhiteSpace)
        .Take(IsLetter, out char first)
        .Take(IsLetterOrDigit, out string rest)
        .Skip(IsWhiteSpace)
        .Let(_id = Concat(first, rest));

TakeIdentifier(" abc123  ", out var id);
Assert.AreEqual("abc123", id);

Sprog Naive XML parser

NetWasm

The package includes a netwasm0.1 build, so Sprog can be used in applications compiled with NetWasm. Building Sprog from source requires the .NET 10 SDK (10.0.303 or newer); the NetWasm SDK is restored from NuGet.

Performance

Preliminary results are promising, with performance over 40x faster than Sprache in a naive XML parsing benchmark, using far less memory and GC usage thanks to Sprogs reliance on the stack rather than heap allocation.

BenchmarkDotNet v0.15.8, macOS 27.0.1 (26A434) [Darwin 27.0.0]
Apple M2 Pro, 1 CPU, 10 logical and 10 physical cores
.NET SDK 10.0.401
  [Host]     : .NET 10.0.12 (10.0.12, 10.0.1226.42308), Arm64 RyuJIT armv8.0-a
  DefaultJob : .NET 10.0.12 (10.0.12, 10.0.1226.42308), Arm64 RyuJIT armv8.0-a

Identifier

Method	Mean	Error	StdDev	Ratio	RatioSD	Gen0	Gen1	Allocated	Alloc Ratio
SprogSimple	36.40 ns	0.202 ns	0.179 ns	1.00	0.01	0.0048	-	40 B	1.00
RegexSimple	105.13 ns	2.071 ns	2.127 ns	2.89	0.06	0.0507	-	424 B	10.60
RegexSourceGenerator	94.77 ns	1.580 ns	1.478 ns	2.60	0.04	0.0507	-	424 B	10.60
SpracheSimple	764.57 ns	3.255 ns	2.541 ns	21.00	0.12	0.6647	0.0029	5560 B	139.00

XML

Method	Mean	Error	StdDev	Ratio	RatioSD	Gen0	Gen1	Allocated	Alloc Ratio
SprogXml	1.133 μs	0.0055 μs	0.0051 μs	1.00	0.01	0.2861	0.0019	2.35 KB	1.00
SpracheXml	47.428 μs	0.2005 μs	0.1777 μs	41.86	0.24	34.8511	1.0986	284.82 KB	121.12

JSON

Method	Mean	Error	StdDev	Ratio	Gen0	Gen1	Allocated	Alloc Ratio
SprogJson	2.983 μs	0.0096 μs	0.0085 μs	1.00	0.6523	0.0076	5.34 KB	1.00
SystemTextJson	3.349 μs	0.0102 μs	0.0096 μs	1.12	0.1793	-	1.49 KB	0.28
NewtonsoftJson	5.642 μs	0.0294 μs	0.0260 μs	1.89	1.6556	0.0610	13.56 KB	2.54

Roadmap

• Improved samples and documentation
• More test coverage