Crate relon_eval_api 

Public, backend-agnostic surface for Relon evaluation.

This crate is the seam between hosts and evaluator backends; it only re-exports the types a caller actually sees:

• Data shapes: Value, Scope, Thunk, RuntimeError.
• Host configuration surface: Context, Capabilities, NativeFnGate, native-fn / decorator registration.
• Policy boundary: the CapabilityGate trait — single source of capability-policy truth consulted by every backend (see capability module docs for the enforcement-timing diff between dispatch-time tree-walker checks and vtable-build-time cranelift checks).
• Backend contract: the Evaluator trait — five &self methods covering one full evaluation lifecycle.

A backend (tree-walking relon_evaluator::TreeWalkEvaluator, cranelift AOT, LLVM AOT, wasm host wrapper, …) implements this single trait; hosts then hold a Box<dyn Evaluator> for dynamic dispatch / backend swap.

Trait object-safety is a hard requirement: every method is &self plus concrete in/out types — no generic methods.

Re-exports

pub use capability::CapabilityGate;

pub use context::Context;

pub use context::GatedNativeFn;

pub use context::LoadingModuleGuard;

pub use decorator::DecoratorPlugin;

pub use decorator::PreEvalOutcome;

pub use error::RuntimeError;

pub use module::ModuleResolver;

pub use module::ModuleSource;

pub use native_fn::EvaluatedArg;

pub use native_fn::NativeArgs;

pub use native_fn::NativeFn;

pub use native_fn::NativeFnCaps;

pub use native_fn::RelonFunction;

pub use scope::ListContext;

pub use scope::Locals;

pub use scope::RootRef;

pub use scope::Scope;

pub use scope::Thunk;

pub use scope::Thunks;

pub use smol_str::SmolStr;

pub use smol_str::SMOL_STR_INLINE_CAP;

pub use value::ClosureData;

pub use value::EnumSchemaData;

pub use value::SchemaData;

pub use value::SchemaField;

pub use value::Value;

pub use value::ValueDict;

Modules

buffer

Typesafe writer + reader for the host <-> wasm binary handshake.

capability

Unified capability decision boundary across evaluator backends.

context

Shared evaluator context: host policy + sandbox state.

decorator

Decorator plugin protocol.

error

inplace_return

Backend-shared host side of the in-place region-walk return ABI (S1/S2 List<List<scalar>>, S3 List<String>, S4 List<Schema>, and pointer-array variant lists such as List<Enum>). When a compiled #main returns a parameter-sourced pointer-array list, the machine code does not copy the value into out_buf. Instead the epilogue reports the arena-absolute offset of the return root via the negative sentinel -(root_abs + 1). The host then:

layout

Static field-offset table for the host <-> wasm binary handshake.

module

Module resolution protocol.

native_fn

Native function interface exposed to host code.

schema_canonical

Deterministic schema serialisation + sha256 digest.

schema_lower

relon_analyzer::SchemaDef -> crate::schema_canonical::Schema conversion.

scope

Lexical and runtime context shared across evaluation steps.

smol_str

Short-string optimization (SSO) for Value::String.

value

verifier

Host-walk bounds verifier for the binary handshake buffer.

Structs

Capabilities

Context-wide sandbox policy the host hands the evaluator. The per-bit booleans are the capabilities the host grants; per-function requirements live on NativeFnGate. A call goes through iff every bit declared on the fn’s gate is also set here — there is no per-name allowlist or global short-circuit, so a successful call proves that every bit on its gate was granted.

NativeFnGate

Capability requirements declared per native function at registration time. The gate compares these against the context-wide Capabilities grant when the function is invoked under sandbox.

ResourceBudget

Evaluator-side resource budget.

Enums

CapabilityBit

Canonical assignment of capability bits to stable bit positions.

ResourceBudgetProfile

Evaluator-side resource-budget presets.

Traits

Evaluator

Backend-agnostic evaluator contract.