Struct RustBindingConfig 

pub struct RustBindingConfig<'a> {

    pub struct_attrs: &'a [&'a str],
    pub field_attrs: &'a [&'a str],
    pub struct_derives: &'a [&'a str],
    pub method_block_attr: Option<&'a str>,
    pub constructor_attr: &'a str,
    pub static_attr: Option<&'a str>,
    pub function_attr: &'a str,
    pub enum_attrs: &'a [&'a str],
    pub enum_derives: &'a [&'a str],
    pub needs_signature: bool,
    pub signature_prefix: &'a str,
    pub signature_suffix: &'a str,
    pub core_import: &'a str,
    pub async_pattern: AsyncPattern,
    pub has_serde: bool,
    pub type_name_prefix: &'a str,
    pub option_duration_on_defaults: bool,
    pub opaque_type_names: &'a [String],
    pub skip_impl_constructor: bool,
    pub cast_uints_to_i32: bool,
    pub cast_large_ints_to_f64: bool,
    pub named_non_opaque_params_by_ref: bool,
    pub lossy_skip_types: &'a [String],
}

Configuration for Rust binding code generation.

Fields

struct_attrs: &'a [&'a str]

Attrs applied to generated structs, e.g. ["pyclass(frozen)"].

field_attrs: &'a [&'a str]

Attrs applied to each field, e.g. ["pyo3(get)"].

struct_derives: &'a [&'a str]

Derives applied to generated structs, e.g. ["Clone"].

method_block_attr: Option<&'a str>

Attr wrapping the impl block, e.g. Some("pymethods").

constructor_attr: &'a str

Attr placed on the constructor, e.g. "#[new]".

static_attr: Option<&'a str>

Attr placed on static methods, e.g. Some("staticmethod").

function_attr: &'a str

Attr placed on free functions, e.g. "#[pyfunction]".

enum_attrs: &'a [&'a str]

Attrs applied to generated enums, e.g. ["pyclass(eq, eq_int)"].

enum_derives: &'a [&'a str]

Derives applied to generated enums, e.g. ["Clone", "PartialEq"].

needs_signature: bool

Whether the backend requires #[pyo3(signature = (...))]-style annotations.

signature_prefix: &'a str

Prefix for the signature annotation, e.g. "#[pyo3(signature = (".

signature_suffix: &'a str

Suffix for the signature annotation, e.g. "))]".

core_import: &'a str

Core crate import path, e.g. "liter_llm". Used to generate calls into core.

async_pattern: AsyncPattern

Async pattern supported by this backend.

has_serde: bool

Whether serde/serde_json are available in the output crate’s dependencies. When true, the generator can use serde-based param conversion and add serde::Serialize derives. When false, non-convertible Named params fall back to gen_unimplemented_body.

type_name_prefix: &'a str

Prefix for binding type names (e.g. “Js” for NAPI/WASM, “” for PyO3/PHP). Used in impl block targets: impl {prefix}{TypeName}.

option_duration_on_defaults: bool

When true, non-optional Duration fields on has_default types are emitted as Option<u64> in the binding struct so that unset fields fall back to the core type’s Default implementation rather than Duration::ZERO. Used by PyO3 to prevent validation failures when request_timeout is unset.

opaque_type_names: &'a [String]

Opaque type names. Structs with non-optional fields of these types skip Default/Serialize/Deserialize derives since opaque wrappers don’t impl them.

skip_impl_constructor: bool

When true, the impl block constructor (fn new(...)) is suppressed regardless of whether the type has fields. Useful for backends (e.g. extendr) that generate a separate kwargs-style free-function constructor instead of an in-class new().

cast_uints_to_i32: bool

When true, small unsigned/signed ints (u8, u16, u32, i8, i16) are cast from i32 in gen_lossy_binding_to_core_fields. Used by the extendr backend where R maps small ints to i32.

cast_large_ints_to_f64: bool

When true, large int/size types (u64, usize, isize) are cast from f64 in gen_lossy_binding_to_core_fields. Used by the extendr backend where R maps large ints to f64.

named_non_opaque_params_by_ref: bool

When true, Named non-opaque struct parameters in free function signatures are emitted as &T (reference) instead of T (owned). Required for the extendr backend because #[extendr] only generates TryFrom<&Robj> for &T, not for T, so owned struct params cannot be passed through the FFI layer.

lossy_skip_types: &'a [String]

Types that have no From<BindingType> impl (e.g. output-only flat data enums). When gen_lossy_binding_to_core_fields encounters a field whose TypeRef::Named type is in this slice, it emits Default::default() instead of .clone().into().