Pris

Pris is a domain-specific language for designing slides and other graphics.

Example

The obligatory “hello world”:

{
  put t("Hello world") at (0.1w, 0.5h)
}

And to show a little more of the language, here is a slightly more elaborate program that also draws lines:

top_left = (0w, 0h)
top_right = (1w, 0h)
bottom_left = (0w, 1h)
bottom_right = (1w, 1h)

{
  put line(bottom_right) at top_left
  put line(top_right - bottom_left) at bottom_left

  font_family = "Cantarell"
  font_size = 0.3h
  color = #882244
  put t("A language for designing slides.") at (0.1w, 0.1w + font_size)
}

{
  color = #000000
  put line((1w, 0h)) at (0w, 0.5h)
}

It creates two slides, the first one with a cross in it, the second one with a horizontal line. The first slide contains text in dark purple.

Comparison to other technologies

• Pris is similar to LaTeX with Beamer in the sense that you write your slides in a text-based, human readable format, from which a pdf is produced. Pris differs from LaTeX with Beamer in not doing any lay-out. All elements must be placed manually.
• Pris is similar to reveal.js in that its control over visuals superficially resembles css. It differs from reveal.js in requiring a separate compilation step that renders a pdf. It differs from html in being imperative rather than declarative.
• Pris is similar to TikZ in LaTeX, in the sense that it is a domain-specific language for creating graphics. It is similar in providing complete control over where elements are placed. Pris differs from TikZ in not being embedded in LaTeX. It has a more modern syntax, and it has first class support for computation. For instance, arithmetic with coordinates is supported out of the box, and Pris has proper functions, rather than TeX macros.
• Pris is similar to Fran, in having first-class, composable graphics (although implementation is a work in progress). Pris differs from Fran in not being embedded in Haskell. Pris differs from Fran in placing emphasis on graphics rather than animation.
• Pris is similar to Diagrams in being a domain-specific language with first-class composable graphics, giving complete control over layout. Pris differs from Diagrams in not being embedded in Haskell. Pris differs from Diagrams in its styling system. Customization in Pris resembles CSS due to dynamic scoping, whereas in Diagrams functions pass around a style value.
• Pris is vaguely similar to Powerpoint and graphical editors like Illustrator or Inkscape in providing complete control over where elements are placed. It differs in being a text-based format intended to be edited with a text editor, rather than with a graphical editor.
• Pris is similar to an html canvas element, or to drawing with Skia or Cairo, in providing complete control over how graphics are drawn. It differs from direct canvas drawing in being more high-level (graphic elements can be manipulated as first-class values), and in being a domain-specific language rather than being controlled by a general-purpose scripting language.

Documentation

• A language for designing slides, a blog post that details the motivation for building Pris.
• Examples, small examples that demonstrate one feature at a time.
• Ask questions in the Gitter chatroom, or send me an email.
• The online documentation (a work in progress).

Building

Pris uses Cairo for drawing and Harfbuzz for text shaping, and links against libcairo.so and libharfbuzz.so. It uses Rsvg to render svg images, for which it links against librsvg-2.so. Ensure that these are installed:

# On Ubuntu
apt install fonts-cantarell libcairo2-dev libharfbuzz-dev librsvg2-dev

# On Arch
pacman -S --needed cantarell-fonts cairo harfbuzz librsvg fontconfig freetype2

Pris is written in Rust and builds with Cargo, the build tool bundled with Rust.

cargo build --release
target/release/pris examples/lines.pris
evince examples/lines.pdf

License

Pris is free software. It is licensed under the GNU General Public License, version 3.