Struct CodecOptions 

pub struct CodecOptions {
    pub recursion_limit: usize,
}

Encoding and decoding options for a Codec.

Construct with Default and adjust what you need, so that options added in future versions keep their defaults:

use capnp_json::{Codec, CodecOptions};

let codec = Codec::new_with_options(CodecOptions {
  recursion_limit: 32,
  ..Default::default()
});

Fields

recursion_limit: usize

How deeply decoding will recurse before giving up. Defaults to 64, matching the C++ codec’s maxNestingDepth.

Decoding is recursive, so without a bound, deeply nested input exhausts the stack and aborts the process — which is not a catchable error in Rust. The limit turns that into an ordinary Err.

It bounds two things: the nesting depth of the JSON itself, and the depth of the walk over the schema. The second is not implied by the first, because a struct that flattens a field of its own type recurses on the schema without descending into the JSON at all.

A limit of N admits N nested arrays or objects. Scalars do not count against it, so the boundary is the same one the C++ codec applies at the same numeric setting.

Raising this reintroduces the crash it exists to prevent. The safe ceiling depends on your build profile and the stack size of the thread doing the decoding; measured on a 1 MiB stack, decoding survived depth 1600 in release but overflowed at depth 200 in debug. The default is comfortably safe in both. Lowering it is always safe.

Trait Implementations

impl Clone for CodecOptions

fn clone(&self) -> CodecOptions

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for CodecOptions

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

Formats the value using the given formatter.

impl Default for CodecOptions

fn default() -> Self

Returns the “default value” for a type.

impl Eq for CodecOptions

impl PartialEq for CodecOptions

fn eq(&self, other: &CodecOptions) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl StructuralPartialEq for CodecOptions