Glossary

Every Tachyonn term, defined once.

The language

.tac — The Tachyonn markup file. One file is one deck.

Block — A self-contained unit of content that lands on a slide — a paragraph, a list, an image, a code sample, a table, a highlight box. You write blocks in order; Tachyonn arranges them. See Essential Concepts.

Markup signal — The small character at the start of a line that says what kind of block follows — #, -, >, `.

Function — An identifier followed by parameters in brackets: &[url, label], ![img.png], +[x^2]. Used when a single symbol isn't enough. The common ones have single-character names.

Directive — /name[arg, key=value] — an instruction rather than content: /layout[grid], /notes[…], /component[QrCode, url=…], /icon[].

Modifier — A short option in angle brackets at the start of a function's arguments: ![<c> photo.jpg] centres the image, ###<a> makes the box an alert. Every modifier has a name=value synonym — <c> is align=center.

Frontmatter — The === … === block that carries metadata and style keys. There is one at the top of the deck, and optionally one right after a ## for that slide alone.

tac.config — A frontmatter-shaped file in a directory. Every deck at or below that directory inherits its keys and macros. The nearest one wins; the deck's own frontmatter wins over all of them.

.tt file — A theme file — the same key syntax as frontmatter, saved and reused. Applied with theme: path/to/file.tt.

Structure

Section — A slide made by a # heading — the divider that opens a part of the talk. Sections are the columns of the overview and the entries of the table of contents.

Slide — A ## heading and everything under it, up to the next heading.

Highlight box (callout) — A titled panel inside a slide, opened with ###. Not a new slide. See Highlight Boxes.

Label (id) — A name attached to a slide with :: id at the end of its heading line, so :[id] can link to it.

Layout — How a slide arranges its content — standard, two-column, grid, quote, code-window, and the rest. Set with /layout[name]. See Layouts.

Presenting

Click (step) — One press of the forward key within a slide. >[2]{…} appears on click 2.

Reveal — Content that enters or leaves on a click, written >[n]{…} / <[n]{…}.

Reserve / push — The two ways a hidden reveal can behave. Reserve (the default) keeps its space, so the layout never moves between clicks; push collapses it, so revealing pushes the content below down. Switch with reveal:. See Animations.

Auto-fit — The mechanism that shrinks a slide's font until the content fits the stage — reflowing the text rather than scaling it, so the slide fills the width instead of leaving a gap. Content never scrolls and never gets clipped.

Transition — The motion between two slides: slide, slide-in, slide-out-in, fade, zoom, none. Direction is derived from the deck's geometry — horizontal between sections, vertical within one.

Magic Move — A transition where elements shared by two slides fly from their old position to the new one instead of cutting. Marked with a [text]{.magic-NAME} span on both slides; the title morphs automatically.

Presenter mode — The second window — current slide, next state, notes, timer. Cmd/Ctrl + P.

Next state — What the presenter previews. Not the next slide: while the current slide has clicks pending, it shows that slide one click ahead.

Overview — The 2D map of the deck (O) — sections as columns, their slides stacked below.

Under the hood

IR (SlideDeck) — The JSON the Rust parser produces and the Vue renderer consumes. It's the only interface between the two halves of Tachyonn: Rust never emits HTML, the frontend never reads .tac.

Preview — The live, hot-reloading view you write against — tachyonn preview deck.tac, or the app's own window. It has an authoring menu the real presentation doesn't.