Skip to content
Beskid Platform specification

Beskid

Jump to a Beskid service

Beskid

Jump to a Beskid service

Memory and references

Platform spec node

Memory and references

Back to Memory model Open in platform map

Spec standingStandard

Owner
Piotr Mikstacki
Submitter
Piotr Mikstacki

Normative specification

Section titled “Normative specification”

Scope

Section titled “Scope”

Defines local storage, ref/out parameters, GC-managed heap objects, arrays, and cross-fiber sharing at the language level. Collector algorithms and write barriers must match execution platform-spec; the /execution/ doc tree is informative only.

Locals and assignment

Section titled “Locals and assignment”
  • Locals live in function activation records unless captured by closures (see Lambdas and closures).
  • Assignment to immutable bindings must error (E1214).
  • mut on locals and parameters must be present to allow reassignment where required by the reference compiler.

ref and out

Section titled “ref and out”
  • Parameters may use ref T or out T modifiers (ParameterModifier).
  • ref passes an alias to existing storage; out requires definite assignment before read on callee entry.
  • ref in type expressions (ref T) denotes reference types in signatures distinct from by-value T.

Arrays

Section titled “Arrays”
  • T[] values use the fat-pointer layout (BeskidArray) described in execution ABI material.
  • Element access must respect bounds checks in safe builds (lowering inserts checks unless proven).

Heap and garbage collection

Section titled “Heap and garbage collection”
  • Reference-bearing values that escape their defining frame must live on the GC heap traced by the runtime collector (concurrent tri-color mark-sweep in the reference implementation).
  • User code must not expose manual free or untracked pointers in v0.1.
  • Pointer stores to heap objects must execute write barriers when required by the active GC phase (see execution memory contracts).
  • null must not appear as a value; optional absence uses Option<T> per Types.

Fibers and sharing

Section titled “Fibers and sharing”
  • Values must not be shared across fibers by alias unless immutability is proven or synchronization uses Channel<T> per Fibers and spawn.
  • Capturing mutable shared state in spawn closures should be rejected when detectable.

Dynamic semantics

Section titled “Dynamic semantics”
  • Stack frames are tied to call/return; return ends the frame and invalidates temporaries.
  • Closure environments must outlive uses tracked by the compiler’s capture analysis.

Diagnostics

Section titled “Diagnostics”

Immutability E1214; member access E1211–E1213. Registry: Diagnostic code registry.

Conformance

Section titled “Conformance”

Memory rules enforced in beskid_analysis must be preserved in codegen for L3 claims.

Decisions

Section titled “Decisions”
  • D-LM-MEM-001 — Channel-only fiber sharing: Language law forbids ad hoc shared mutable globals across fibers.
  • D-LM-MEM-002 — Fat-pointer arrays: All T[] share one ABI representation per target unless a profile documents otherwise.
  • D-LM-MEM-003 — GC by default: Heap objects are collector-managed; escape analysis may stack-allocate but must not skip tracing when pointers escape.
  • D-LM-MEM-004 — No null addresses: References are non-null at the type level; Option<T> models absence.

Platform view

Section titled “Platform view”

Locals, ref T, GC-traced heap objects, and channel-mediated sharing. Runtime barrier and phase details live under platform-spec execution; /execution/ pages are a legacy bridge only.