Presentrs

A terminal markdown slideshow renderer built with Ratatui, pulldown-cmark, and syntect.

Key Rule: Every H1 heading (# Title) starts a new slide.

Quick Start

cargo run --release -- README.md

Any .md file works:

cargo run --release -- my-talk.md

Navigation

Key	Action
→, l, Space, PageDown	Next slide
←, h, PageUp	Previous slide
↓, j	Scroll down within slide
↑, k	Scroll up within slide
Home	Jump to first slide
End	Jump to last slide
q, Esc	Quit

The slide counter and full keybinding hint are shown in the status bar at the bottom. Resizing the terminal while presenting is supported — slides re-render automatically so H1 titles stay centered.

Supported Markdown

• Headings: H1 creates slides; H2–H6 style content within the current slide.
• Paragraphs, soft/hard breaks, and horizontal rules (---).
• Lists: bulleted and numbered, with nested-indentation preserved.
• Emphasis: *italic*, **bold**, `inline code`.
• Code blocks with syntax highlighting for 50+ languages (see below).
• Tables with Unicode box borders and bold header rows.

Syntax Highlighting

Code blocks are highlighted by syntect's default syntax set, covering languages including:

• Systems: rust, c, cpp/c++/cxx, go, asm
• Web: javascript/js, typescript/ts, html, css, php
• Enterprise: java, csharp/c#/cs, scala, kotlin/kt, groovy
• Scripting: python/py, ruby/rb, perl/pl, lua, powershell/ps1, shell/bash/sh
• Functional: haskell/hs, elixir/ex, erlang/erl, clojure/clj, ocaml, fsharp/f#, lisp, scheme
• Proof assistants: lean/lean4 (custom highlighter — see below)
• Mobile: swift, dart
• Data/Config: json, xml, yaml/yml, toml, ini, properties
• Docs: markdown/md, tex/latex
• Other: sql, dockerfile, makefile, nginx, apache, vim, r, matlab, verilog, vhdl

Lean 4

Presentrs ships a dedicated Lean 4 highlighter — syntect does not include a Lean 4 grammar. Fence a block with lean or lean4 to activate it:

```lean4
theorem add_comm (a b : Nat) : a + b = b + a := by
  induction a with
  | zero => simp
  | succ n ih => simp [Nat.succ_add, ih]
```

The highlighter recognises:

• Keywords (def, theorem, structure, namespace, by, match, …)
• Tactics (simp, rw, exact, apply, induction, rcases, omega, …)
• Built-in types / sorts (Prop, Type, Sort, Nat, List, Option, …)
• Line comments (-- …), nested block comments (/- /- … -/ -/)
• String and character literals, numeric literals
• Attribute forms like @[simp]
• Lean 4 unicode operators: ∀, ∃, λ, →, ↔, ∧, ∨, ¬, ≤, ⟨⟩, ⊢, and more

Example

Create slides.md:

# Welcome
Intro content

# Problem
- Bullet
- Another bullet

# Solution

```rust
fn main() {
    println!("Hello");
}

Thanks

Run it:

```bash
cargo run --release -- slides.md

Further Reading

• TUTORIAL.md — a walkthrough of every feature, delivered as its own slideshow.
• demo.md — a small end-to-end demo including Lean 4.