Creating and Publishing the text2numR Package: Step-by-Step Guide

I recently tried creating a simple R package—text2numR—with the help of ChatGPT. The process was surprisingly smooth and educational, especially for someone new to R package development. You can check out the finished project here: hasindu-k/text2numR.

Let’s walk through how it was done, step by step:

 

🔧 Step 1: Start a New Package Project

1. Open RStudio

2. Navigate to: File > New Project > New Directory > R Package

3. Choose a name for your package (e.g., text2numR)

4. Click "Create Project"

🖋️ Step 2: Add Your Functions

Create your R function files inside the /R folder:

encode_text.R

#' Encode a string into numeric positions
#'
#' @param text A character string
#' @return A numeric vector
#' @export
encode_text <- function(text) {
  chars <- strsplit(tolower(text), "")[[1]]
  match(chars, letters)
}

decode_text.R

#' Decode numeric positions into a string
#'
#' @param nums A numeric vector
#' @return A character string
#' @export
decode_text <- function(nums) {
  if (!is.numeric(nums)) {
    stop("Input must be a numeric vector.")
  }
  valid <- ifelse(nums >= 1 & nums <= 26, nums, NA)
  output <- ifelse(is.na(valid), "?", letters[valid])
  paste0(output, collapse = "")
}

📄 Step 3: Document and Build Your Package

Use roxygen2 for inline documentation, then run:

devtools::document()
devtools::build()

🚀 Step 4: Connect to GitHub

1. Go to: Tools > Version Control > Project Setup

2. Initialize Git (if not already done)

3. Then in the console:

usethis::use_github()

🚀 Step 5: Add GitHub Actions for R CMD Check

In the console, run:

usethis::use_github_action_check_standard()

This creates .github/workflows/R-CMD-check.yaml to automate package checks.

📝 Step 6: Add a LICENSE File

Use the MIT license via:

usethis::use_mit_license("Hasindu Koshitha")

✅ Step 7: CRAN-Prep Checklist

Check	Command
Spelling	spelling::spell_check_package()
Unit Tests	devtools::test()
Local R CMD Check	devtools::check()
Windows R-devel Check	devtools::check_win_devel()
Build PDF Manual	devtools::build_manual()
Add NEWS.md	usethis::use_news_md()

🚀 What text2numR Does

• Converts alphabetic strings into numeric sequences (e.g., "cab" → 3 1 2)

• Converts numeric vectors back into text (e.g., 3 1 2 → "cab")

• Supports:

  • Case insensitivity

  • Error handling (non-letter characters)

  • Batch processing

Ready to go live on GitHub and optionally submit to CRAN!