Module host 

Structs

Atom

The newtype carries the PartialEq, Debug and Display that dyn HostType cannot, which lets Exp keep a derived PartialEq.

OpDef

Registry

Names resolve to indices once, in the reader, so a call site costs an array index and not a hash lookup.

Str

The worked example: a host type is a payload, a name, an equality, an encoding.

Traits

HostType

Data, emphatically: an atom declares a wire encoding because it must cross a channel as a message payload. What cannot encode is a capability, and capabilities are addresses.

Functions

builtins

install

Must happen before the first read, since reading is what resolves names to indices. An embedder extends crate::registry rather than starting empty.

registry

The default is the whole language’s table, not this file’s: the reader resolves names and sits below every layer that adds to it, so an op the surface adds would otherwise be unreachable.

Type Aliases

Decoder

OpResult

An op’s failure is an ordinary narju value, so a partial op is a throw the program can catch, not a second error channel.