blockst 0.4.0 — Introduction

Introduction#

About blockst#

blockst renders block-based programs in Typst documents, each drawn the way its editor draws it:

Scratch 3 — scratch(), the Scratch look in 26 languages, including right-to-left scripts, with an execution engine for turtle graphics and helpers for importing .sb3 project files.
Blockly — blockly(), today’s flat Blockly and the pre-2019 look, with profiles for the Jugendwettbewerb Informatik (jwinf.de) and its robot and turtle blocks.
MakeCode — makecode(), the micro:bit and Calliope mini editors’ blocks in all 36 of their languages.
NEPO (Open Roberta) — nepo(), the Calliope mini and micro:bit blocks of Open Roberta Lab.

All four share one text notation: a block per line, (…) for a value, [… v] for a dropdown, <…> for a condition, indentation and an end marker for the body of a loop. Typst hands the text to a bundled WASM plugin, the plugin parses it and returns SVG, Typst embeds the SVG. Nothing has to be installed beyond the package.

Core Design

Fully text-based: write blocks as plain text, get rendered blocks. The same notation for every editor.
Each editor’s own geometry, palette and vocabulary — jwinf’s classic Blockly measured on jwinf.de, MakeCode’s zelos renderer as the editors run it.
Localized: Scratch’s official translations, Blockly’s message files, the MakeCode editors’ own strings.
Themes for print (print, grayscale, high-contrast) and the document’s own category colours over any palette.
Line numbers and line labels for worksheets that talk about single lines.

Breaking Change since 0.2.0

The old pre-0.2.0 native-Typst renderer syntax is removed. From 0.2.0 onward, blockst uses only the text-to-WASM pipeline. Documents that still rely on the previous syntax must be migrated.

Quick start#

#import "@preview/blockst:0.4.0": scratch, blockly, makecode, nepo

#scratch("
when green flag clicked
move (10) steps
turn cw (15) degrees
")

The same document can hold the other editors’ blocks. A jwinf task:

#blockly("
Roboter-Programm
wiederhole (4) mal:
  gehe nach rechts
  falls <auf Kiste>
    hebe Murmel auf ::aktionen
  ende
ende
", profile: "jwinf")

A micro:bit program:

#makecode("
beim Start
  zeige Symbol [Herz v]
ende
wenn Knopf [A v] geklickt
  zeige Zahl ((1) + (2))
  pausiere (ms) (100)
ende
")

Which function for which editor#

Editor	Function	Profiles	Default language	Code fences
Scratch 3	`scratch()`	—	`"en"`, 26 languages	`scratch` via `raw-scratch()`
Blockly, jwinf	`blockly()`	`blockly` (default), `blockly-klassisch`, `jwinf`, `jwinf-turtle`	`"de"`, 24 languages	`blockly`, `jwinf`, `jwinf-turtle` via `raw-blockly()`
MakeCode	`makecode()`	`makecode` (micro:bit, default), `makecode-calliope`	`"de"`, 36 languages	`makecode`, `microbit`, `calliope` via `raw-makecode()`
Open Roberta	`nepo()`	platforms `calliope` (default), `calliopev3`, `microbit`	`"de"`	`nepo` via `raw-nepo()`

Every function takes the same rendering options — theme, scale, font, line numbers, colours — and all of them read the defaults set with set-blockst(). The chapters Scratch, Blockly and jwinf, MakeCode and NEPO describe what is particular to each editor.

Package information#

Version: 0.4.0
License: MIT
Repository: github.com/Loewe1000/blockst
Compiler requirement: Typst 0.15.0+
Font requirement: Scratch and Blockly labels are designed for Helvetica Neue. On Linux/Windows install a compatible font (e.g. Nimbus Sans) or set another one with set-blockst(font: …). MakeCode labels use a monospace face — Menlo, Consolas or DejaVu Sans Mono, whichever is installed.