Struct Remapper 

pub struct Remapper { /* private fields */ }

Recursively replaces DataTypes within a DataType structure from a set of remap rules.

Remapper is useful when a type should be represented differently for export without changing the original Rust type or derive output. It performs DataType equality checks while walking the DataType structure applying the transformations.

Rules are applied in the order they are registered. For each visited DataType, every matching rule is applied, with each rule seeing the result of the previous matching rule.

WARNING: This is an advanced API!

It needs to be used carefully as it can easily break the safety of the end to end type contract.

You must ensure you have Serde applying the same transformations to the runtime data for it to be sound.

Examples

Remap u32 to str and i32 to bool:

use specta::{Types, datatype::{DataType, Field, List, NamedDataType, Primitive, Struct}};
use specta_util::Remapper;

let remapper = Remapper::new()
    .rule(Primitive::u32.into(), Primitive::str.into())
    .rule(Primitive::i32.into(), Primitive::bool.into());

// For a single `DataType`
assert_eq!(
    remapper.remap_dt(DataType::List(List::new(Primitive::u32.into()))),
    DataType::List(List::new(Primitive::str.into()))
);

// For a whole collection of types
let types: Types = remapper.remap_types(Types::default());

Implementations

impl Remapper

pub fn new() -> Self

Creates a remapper with no rules.

pub fn rule(self, from: DataType, to: DataType) -> Self

Registers a rule that replaces exact matches of from with to.

Rules are checked in the order they are registered.

pub fn remap_dt(&self, dt: DataType) -> DataType

Applies the remap operation to a datatype, returning the remapped datatype.

pub fn remap_types(&self, types: Types) -> Types

Applies the remap operation to every datatype in a Types collection, returning the remapped collection.

Trait Implementations

impl Clone for Remapper

fn clone(&self) -> Remapper

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Remapper

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

Formats the value using the given formatter.

impl Default for Remapper

fn default() -> Remapper

Returns the “default value” for a type.