OfficeIMO.CSV

Why OfficeIMO.CSV?

OfficeIMO.CSV treats CSV files as first-class documents rather than raw text. Define a schema, map rows to typed objects automatically or with AOT-friendly delegates, validate on read, and stream through files of any size. Its checked-in NativeAOT smoke publishes a real parser, executes it, and verifies the resulting header schema.

Features

• Document-centric CSV model — headers, rows, and metadata wrapped in a structured document object
• Schema definition & validation — declare column names, types, and constraints; reject invalid rows at parse time
• Typed mapping — map headers automatically for ordinary DTOs or use explicit delegates for trimming and NativeAOT
• Forward-only reads for large files — process rows through the standard DbDataReader contract
• Sort, filter & transform — chain LINQ-style operations directly on the CSV document
• NativeAOT scenario in CI — publishes and executes CSV parsing with schema readback instead of inferring compatibility from dependencies
• Zero external dependencies — ships as a single assembly with no third-party references

Quick start

using OfficeIMO.CSV;
using System.Globalization;

var document = CsvDocument.Load("employees.csv")
    .EnsureSchema(schema => schema
        .Column("Name").AsString().Required()
        .Column("Department").AsString().Optional()
        .Column("Salary").AsType(typeof(decimal)).Required()
        .Column("StartDate").AsDateTime().Optional()
    )
    .ValidateOrThrow();

var employees = document
    .RowsAs<Employee>(map => map
        .FromColumn<string>("Name", (employee, value) => employee with { Name = value })
        .FromColumn<string>("Department", (employee, value) => employee with { Department = value })
        .FromColumn<decimal>("Salary", (employee, value) => employee with { Salary = value })
        .FromColumn<DateTime>("StartDate", (employee, value) => employee with { StartDate = value })
    )
    .ToList();

// Filter and transform
var highEarners = employees
    .Where(e => e.Salary > 100_000m)
    .OrderByDescending(e => e.Salary);

foreach (var emp in highEarners)
{
    Console.WriteLine($"{emp.Name} — {emp.Department} — {emp.Salary:C}");
}

using var reader = CsvDocument.OpenDataReader("large-dataset.csv", new CsvLoadOptions
{
    HasHeaderRow = true,
    Culture = CultureInfo.InvariantCulture
});
while (reader.Read())
{
    Console.WriteLine(reader.GetString(reader.GetOrdinal("Name")));
}

public sealed record Employee
{
    public string Name { get; init; } = string.Empty;
    public string Department { get; init; } = string.Empty;
    public decimal Salary { get; init; }
    public DateTime StartDate { get; init; }
}

Compatibility

OfficeIMO.CSV runs on Windows, Linux, and macOS. It handles RFC 4180 compliant files as well as common real-world variations (quoted fields, embedded newlines, BOM markers).

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