Cogo

Cogo (Config for Go) is a lightweight Go package for loading structured configuration from plain text files.
It supports parsing config files written in a key type value format and mapping the values directly into a Go struct.

Example use-case: Loading application settings from .cogo files in a strongly-typed way.

Features

• Easy-to-read config file syntax
• Supports int, bool, float, and string types
• Maps config entries to Go struct fields via reflection
• Helpful error reporting for invalid lines and types

Config File Format

Each line must follow the format:

key type value

• key maps to a field name in the struct (case-insensitive)
• type must be one of: int, bool, float, float64, or string
• value is the value to assign (supports multi-word strings)

Lines starting with # are treated as comments.

Example config.cogo:

# Application settings

Port int 8080
Debug bool true
Rate float 0.75
Name string MyApp

Usage

package main

import (
  "fmt"
  "log"
  "gitlab.com/naranza/cogo"
)

type Config struct {
  Port  int
  Debug bool
  Rate  float64
  Name  string
}

func main() {
  var cfg Config
  err := cogo.LoadConfig("config.cogo", &cfg)
  if err != nil {
      log.Fatal(err)
  }

  fmt.Printf("Loaded config: %+v\n", cfg)
}

Testing

To run unit tests, ensure you have the Go toolchain installed and run:

go test ./...

Your tests are in gogo_test.go and expect test config files to exist in a files/ subdirectory.

Project Structure

/cogo
  ├── cogo.go           // Core implementation
  ├── tests/            // Unit tests and config files

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License

AGPL-3.0 Copyright © 2025 Andrea Davanzo and contributors