WIP

[toyboot4e]

Let's make it a real thing :)

1. Primitive language (WIP)

1-1. Frontend IR

• Parse Item s
• Lower procedure Body
• Collect Body expressions and patterns into ExprScopeMap
• Collect ItemScope and ExprScopeMap into Resolver

1-2. Simple type inference

• Add type data subtable to procedure body: TypeTable
• Infer types
• Resolve paths to items and retrieve their types

1-3. Simple langauge features

• Local variables (let)
• i32, f32 and builtin operators
• bool
• Control flow 1 (when, unless, cond, while)
• Explicit block scope (do)
• User-defined procedures
• Procedure call
• Annotate procedure parameter types
• return
• Control flow 2 (loop, continue, break)
• String literals
• GC
• Print functions
• Assertions

1-4. Utilities

• Debug representation of patterns and expressions
• Accumulate diagnostics in each path
• Rendering diagnostics

1-5. Basic IDE support

• Diagnostics
• Go to definition
• Rename symbol
• Inlay hints

1-6. More IRs

• Validated IR?
• BIR? (MIR-like CFG-based IR, but also for frontend)

2. Extendible the language (TODO)

2-1. User-defined types

• Struct syntax support
• Allow field access with dots (Path)

2-2. Missing features

• Global variables
• Pure functions (fn)
• Inner items
• Comprehensive match

2-3. Generics

• Generic types, generic type inference
• Generic function
• Array
• Map

2-4. Modules

• Inline module (mod special form)
• Visibility
• Import resolution
• Handle name resolution operators (:: or maybe .)

2-5. Macro support

• Macro syntax
• Virtual files originated from macros
• Macro expansion pass

2-6. Multi file support

• External modules
• IDE support

3. More IDE features (TODO)

3-1. Features

• Completions
• Code snippets
• Search symbols

3-2. Optimizations

• Faster re-parse?

3-3. LSP

• tower_lsp

4. Scripting features

• Coroutines
• Matching over macro inputs
• Rust bindings(Vec, HashMap, etc.)
• Typed path variables (over asset paths)

[toyboot4e]

ra hir_def notes

Data types

Type	Item	Body (patterns / expressions)
Arena	ItemTree	Body
Source map	AstIdMap	AstIdMap, BodySourceMap
Scope	ItemScope (DefMap, ModuleData)	ExprScopes

Terms

• Arena: Push-only Vec
• Interning: Fly object pattern, often with salsa IDs
• Lowering: Converting AST into HIR types in Arena
• Source map:
  • AstIdMap: Map between rather stable index (Idx) and AST syntax (SyntaxNodePtr)
  • BodySourceMap: Map betweens HIR Arena item's Idx and AST syntax (SyntaxNodePtr)