Dameng.SepEx 0.2.5

Dameng.SepEx

A high-performance source generator for working with separated values (CSV/TSV) files in C#. This library extends the excellent Sep library by providing compile-time code generation for strongly-typed reading and writing of CSV data.

Features

• Source Generator: Automatically generates type-safe CSV readers and writers at compile time
• High Performance: Built on top of the fast Sep library
• Attribute-Based Configuration: Use attributes to configure column mapping, formatting, and behavior
• Flexible Column Mapping: Support for column names, indexes, default values, and formatting
• Type Safety: Compile-time type checking and IntelliSense support

Installation

Install the NuGet packages:

dotnet add package Dameng.SepEx
dotnet add package Dameng.SepEx.Generator

Quick Start

1. Define your data model with attributes:

[GenSepParsable]
public partial class Person
{
    [SepColumnIndex(0)]
    public string Name { get; set; }
    
    [SepColumnName("Age")]
    public int Age { get; set; }
    
    [SepDefaultValue("Unknown")]
    public string City { get; set; }
    
    [SepIgnore]
    public string InternalId { get; set; }
}

2. Read and write CSV data:

// Reading
using var reader = Sep.Reader().FromFile("people.csv");
foreach (var person in reader.GetRecords<Person>())
{
    Console.WriteLine($"{person.Name} is {person.Age} years old");
}

// Writing
var people = new List<Person> { /* ... */ };
using var writer = Sep.Writer().ToFile("output.csv");
writer.WriteRecord(people);

External Data Model

1. Generate type info using attributes:

[GenSepTypeInfo<Person>()]
public partial class PersonTypeInfo;

2. Read and write CSV data:

// Reading
using var reader = Sep.Reader().FromFile("people.csv");
foreach (var person in reader.GetRecords<Person>(PersonTypeInfo.Person))
{
    Console.WriteLine($"{person.Name} is {person.Age} years old");
}

// Writing
var people = new List<Person> { /* ... */ };
using var writer = Sep.Writer().ToFile("output.csv");
writer.WriteRecord(people, PersonTypeInfo.Person);

Available Attributes

• [GenSepTypeInfo<T>()]: Generate type info for the specified type
• [SepColumnName(string name)]: Specify column name
• [SepColumnIndex(int index)]: Specify column index for reading/writing order
• [SepDefaultValue(object value)]: Set default value when column is missing
• [SepColumnIgnore]: Ignore property/field during CSV operations
• [SepColumnFormat(string format)]: Specify format for writing values

License

This project is licensed under the MIT License - see the LICENSE file for details.

Contributing

Contributions are welcome! Please feel free to submit a Pull Request.