Struct ExternalBuiltin 

pub struct ExternalBuiltin {
    pub seq_name: String,
    pub symbol: String,
    pub effect: Option<Effect>,
}

Definition of an external builtin function

External builtins are functions provided by a runtime extension (like an actor system) that should be callable from Seq code.

Type Safety (v2.0)

All external builtins must specify their stack effect for type checking. The compiler will error if an external builtin is registered without an effect.

Use ExternalBuiltin::with_effect to create builtins with explicit effects.

Fields

seq_name: String

The name used in Seq code (e.g., “journal-append”)

symbol: String

The symbol name for linking (e.g., “seq_actors_journal_append”)

Must contain only alphanumeric characters, underscores, and periods. This is validated at construction time to prevent LLVM IR injection.

effect: Option<Effect>

Stack effect for type checking (required as of v2.0).

The type checker enforces this signature at all call sites. The compiler will error if this is None.

Implementations

impl ExternalBuiltin

pub fn new(seq_name: impl Into<String>, symbol: impl Into<String>) -> Self

👎Deprecated since 2.0.0: Use with_effect instead - effects are now required

Create a new external builtin with just name and symbol (deprecated)

Deprecated

As of v2.0, all external builtins must have explicit stack effects. Use ExternalBuiltin::with_effect instead. Builtins created with this method will cause a compiler error.

Panics

Panics if the symbol contains invalid characters for LLVM IR. Valid symbols contain only alphanumeric characters, underscores, and periods.

pub fn with_effect( seq_name: impl Into<String>, symbol: impl Into<String>, effect: Effect, ) -> Self

Create a new external builtin with a stack effect

Panics

Panics if the symbol contains invalid characters for LLVM IR.

Trait Implementations

impl Clone for ExternalBuiltin

fn clone(&self) -> ExternalBuiltin

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for ExternalBuiltin

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.