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Scaffold a new Pegium language with a single command — no cloning or GitHub account required:

curl -fsSLO https://ydaveluy.github.io/pegium/pegium-new.cmake && \
  cmake -DNAME=MyLang -DEXT=.ml -P pegium-new.cmake
cd mylang && cmake -B build && cmake --build build -j
./build/mylang-cli example/hello.ml

The script creates a mylang/ directory, pulls Pegium in via FetchContent, and gives you a working "Hello world" grammar, CLI, LSP server, and VS Code extension in one step. No extra runtime beyond CMake is required to scaffold. Node.js is only needed if you keep the VS Code extension enabled (the default).

Prefer to start from an existing example?

The four working examples under examples/ demonstrate every concept in this workflow, so copying the closest one is a fully in-repo, verifiable starting point. statemachine is the smallest complete language (AST + grammar + validation + formatter); arithmetics is the smallest full parser-to-editor path. See Examples.

What the scaffolder creates

A working DSL for a tiny grammar that declares persons and greets them by name:

person John
person Jane

Hello John!
Hello Jane!

You get:

  • src/mylang/ — AST, parser (grammar), core services, LSP services
  • example/hello.<ext> — sample input the smoke test parses
  • CMakeLists.txt — FetchContent_Declare(pegium ...) (one place to bump the pinned tag); sources are globbed, so adding a .cpp under src/ or a test under test/ needs no edit here
  • test/parsing_test.cpp — a CTest smoke test (core pipeline). With the LSP server, test/lsp/ adds feature tests built on the reusable pegium::testing harness, already linked for you
  • .vscode/launch.json — F5 launches the language extension in an Extension Development Host
  • vscode/ — VS Code extension (omitted when -DVSCODE=OFF)

Scaffolding flags

Flag Default Description
NAME (required) PascalCase C++ identifier for your language (e.g. MyLang)
EXT .<lowercased-name> File extension, must start with . (e.g. -DEXT=.ml)
DIR <lowercased-name> Output directory (e.g. -DDIR=my-project)
LSP ON Build the LSP server; pass -DLSP=OFF to skip
VSCODE ON Scaffold the VS Code extension; pass -DVSCODE=OFF to skip
CLI ON Build the CLI tool; pass -DCLI=OFF to skip
PEGIUM_TAG main Pegium tag/commit to pin (e.g. -DPEGIUM_TAG=v1.2.0)

What to edit next

File Role
src/mylang/core/MyLangParser.hpp grammar rules and terminals
src/mylang/core/ast.hpp AST types and reference fields
src/mylang/core/CoreModule.cpp core service wiring (parser, validator…)
src/mylang/lsp/LspModule.cpp LSP feature wiring (formatter, hover…)
example/hello.<ext> sample input the smoke test parses
test/ add tests (globbed — new files need no CMake change)
CMakeLists.txt the Pegium tag this project pins