Raven is a compiler written in TypeScript for the JavaScript ecosystem. The goal is not to replace TypeScript as a toolchain language; the goal is to make Raven's compiler do more of the type work TypeScript asks developers to write manually.

Pipeline

Raven source moves through these stages:

1. Lexer — tokenizes source and records file/line/column locations for diagnostics.
2. Parser — builds the AST and recognizes declarations, expressions, functions, imports, arrays, records, and model declarations.
3. Binder + SymbolTable — records declarations, references, mutability, type, and origin metadata for names visible in a file.
4. TypeChecker — infers expression types, validates assignments and calls, resolves models from the workspace registry, and reports diagnostics.
5. Optimizer — simplifies obvious dead branches and unreachable code.
6. Emitter — emits JavaScript.

Program model

The binder tracks not only what a symbol is, but where it came from:

• local — explicitly declared in this file
• inferred — created from a value with no annotation
• import — resolved from an import declaration
• model — resolved from a published model shape
• builtin — supplied by the compiler/runtime

That origin metadata is the foundation for better future errors like “this field is required because it came from model User in models.rv.”

Type engine

The type engine has two different checks:

• sameType(a, b) asks whether two types are exactly the same.
• isAssignableTo(value, target) asks whether a value can flow into an expected type.

That split matters. JavaScript and TypeScript code often uses compatible shapes that are not textually identical. Raven should understand compatibility without forcing developers to write interface declarations first.

Project model

model declarations publish record shapes into a workspace registry shared by all files in a project. This is how Raven removes export type / import type for project-owned data shapes.

model user = { id: 1, name: "Ada" }

Every file can use user directly. If two files publish the same model name with different shapes, the compiler reports a conflict with a field-level diff.