Module type_tracking 

Type Tracking for Bytecode Compiler

This module tracks known type information during compilation to enable type-specialized code generation. When a variable’s type is known at compile time, the compiler can emit optimized opcodes for field access.

How Types Become Known

Types are known in these situations:

• Explicit type annotation: let x: Candle = ...
• Constructor call: let x = Candle { ... }
• Object literal: let x = { a: 1, b: 2 } (inline struct type)
• Function with declared return type: let x = get_candle()

Usage

The compiler uses this to emit typed field opcodes for dot access:

• GetFieldTyped (specialized): Direct slot access by precomputed offset
• SetFieldTyped (specialized): Direct slot update by precomputed offset Generic GetProp/SetProp are reserved for non-dot operations (index/slice).

Storage Type Hints

For JIT optimization, we track storage types:

• StorageHint::NullableFloat64: Option uses NaN sentinel
• StorageHint::Float64: Plain f64, no nullability
• StorageHint::Unknown: Type not determined at compile time

Structs

BindingSemantics

Ownership/storage metadata for a binding slot.

FrameDescriptor

Typed frame layout metadata.

TypeTracker

Tracks type information for variables during compilation

VariableTypeInfo

Type information for a variable

Enums

Aliasability

BindingOwnershipClass

Source-level ownership class for a binding slot.

BindingStorageClass

Planned runtime storage strategy for a binding slot.

EscapeStatus

MutationCapability

NumericType

Numeric type known at compile time for typed opcode emission.

SlotKind

Describes the storage kind for a single local/parameter slot in a frame.

VariableKind

The kind of variable: regular value, typed table, row view, or column.

Type Aliases

StorageHint

Backwards-compatible alias. Prefer SlotKind in new code.