Rust's “copy on write” Cow abstraction is very useful to avoid costly cloning when dealing with vectors or strings. A Cow allows you to defer allocating new memory until it becomes inevitable. Consider the following example:

use std::borrow::Cow;
fn do_something_or_nothing(v: Cow<str>) -> Cow<str> {
    if v.len() > 3 {
        let s = "Hello ".to_string() + &*v;
        Cow::Owned(s)
    } else {
        v
    }
}

This note shows how to install the Estonian Electronic Identity Software on NixOS.

This blog post shows how to set up Luhmann's Zettelkasten with Tp-Note and how to work with it.

Tp-Note's main design goal is to convert some input text - usually provided by the system's clipboard - into a Markdown note file with a descriptive YAML header and meaningful filename. This blog post explains how to configure Tp-Note for multilingual note-taking. Consider the following note file example:

---
title:    Demokratie und Menschenbild
subtitle: Vorlesung
author:   Prof. Rainer Mausfeld
date:     2023-04-21
lang:     de-DE
---

Kognitionswissenschaftliche Einsichten in die Beschaffenheit des Menschen.

The YAML variable lang: indicates the natural language in which the note text is authored, here de-DE. This IETF language tag is useful when working with grammar and spell checkers. For example: when placed in last position, the grammar checker LanguageTool (LTEX) reads the variable lang: to activate the grammar and spelling rules for the indicated specific language (c.f. blog post). The recently released Tp-Note version 1.21.0 integrates linguistic analysis provided by the Lingua library. This new feature allows Tp-Note to determine automatically the natural language of new note files during their creation process.

One downside when you take notes with your keyboard and laptop is, that you can not enter mathematical formulas.

To remedy this, Tp-Note version 1.19.8 comes with a new feature: its note viewer and internal web-server can now render MathML in note files written in Markdown. It also features syntax highlighting for source code.