PrSM (Pragmatic Reduced Syntax for Metascript) is a Unity-first scripting language toolkit.
It compiles .prsm scripts to readable C# with syntax sugar for components, coroutines,
event listeners, input handling, interfaces, generics, singleton, object pooling,
pattern matching, async/await, state machines, and reactive bindings.
Language 5 adds general yield, attribute targets, preprocessor directives, ref/out/vararg
parameters, nameof, advanced patterns (relational/combinator/positional/property),
with expressions, ref locals, partial declarations, and a DAP debugger adapter.
Includes VS Code extension and Unity Editor package.
README
PrSM
PrSM is a Unity-first scripting language toolkit built around a Rust compiler, a Unity Editor package, and a VS Code extension.
What is in this repository
crates/refraction: the PrSM compiler and CLI
roslyn-sidecar: an optional .NET Roslyn sidecar skeleton for Unity/C# symbol queries
unity-package: the Unity Editor integration and generated-code workflow
vscode-prsm: the VS Code extension, syntax assets, snippets, diagnostics, and Unity-aware tooling
samples: sample .prsm scripts used for local validation and regression checks
Highlights
.prsm source files compile to generated C# for Unity projects
compile/build also emit sidecar .prsmmap.json files next to generated C# for VS Code navigation and Unity generated-script back-mapping
CLI support for compile, check, build, hir, definition, references, index, lsp, init, where, and version
Unity import/build integration with clickable diagnostics, remapped generated-script runtime stack traces, and generated .cs redirect support back to PrSM source
VS Code support for syntax highlighting, snippets, diagnostics, trusted-workspace prism lsp navigation, explorer tooling, and generated C# hover/navigation
Automated BlazeTest EditMode smoke coverage for import, rename, delete, and diagnostic flows
In-repo Unity package EditMode tests for project config, diagnostic formatting, compiler resolution, and source-map helpers
Quick Start
Compiler
cargo test
cargo run -p refraction --bin prism -- compile samples\PlayerController.prsm --output build-output
cargo run -p refraction --bin prism -- hir . --json
cargo run -p refraction --bin prism -- definition . --json --file samples\PlayerController.prsm --line 10 --col 5
cargo run -p refraction --bin prism -- references . --json --file samples\PlayerController.prsm --line 10 --col 5
cargo run -p refraction --bin prism -- index . --json
cargo run -p refraction --bin prism -- index . --json --file samples\PlayerController.prsm --line 10 --col 5
cd vscode-prsm
npm install
npm test
npm run package
Roslyn sidecar skeleton
cd roslyn-sidecar
dotnet build
The Rust LSP can launch it when PRISM_ROSLYN_SIDECAR_EXE is set. Unity metadata references are discovered from .prsmprojectcompiler.target_unity, PRISM_UNITY_MANAGED_DIR, PRISM_UNITY_EDITOR_DIR, and Library/ScriptAssemblies when available.
