candid/types/
mod.rs

1//! Provides Candid type conversion and serialization.
2//!  * `CandidType` trait converts a Rust type to Candid type `types::Type`. The implementation for user-defined data types can be derived from `candid_derive` crate.
3//!  * `Serializer` trait serializes a Rust value to Candid binary format.
4//!    We do not use Serde's `Serialize` trait because Candid requires serializing types along with the values.
5//!    This is difficult to achieve in `Serialize`, especially for enum types.
6
7use serde::ser::Error;
8
9mod impls;
10pub mod internal;
11pub mod subtype;
12pub mod type_env;
13#[cfg_attr(docsrs, doc(cfg(feature = "value")))]
14#[cfg(feature = "value")]
15pub mod value;
16
17pub use self::internal::{
18    get_type, Field, FieldDoc, FuncMode, Function, Label, SharedLabel, Type, TypeDoc, TypeDocs,
19    TypeId, TypeInner,
20};
21pub use type_env::TypeEnv;
22
23pub mod bounded_vec;
24pub mod leb128;
25#[cfg(feature = "bignum")]
26pub mod number;
27pub mod principal;
28pub mod reference;
29pub mod reserved;
30pub mod result;
31
32pub mod arc;
33pub mod rc;
34
35pub trait CandidType {
36    // memoized type derivation
37    fn ty() -> Type {
38        let id = Self::id();
39        if let Some(t) = self::internal::find_type(&id) {
40            match *t {
41                TypeInner::Unknown => TypeInner::Knot(id).into(),
42                _ => t,
43            }
44        } else {
45            self::internal::env_add(id.clone(), TypeInner::Unknown.into());
46            let t = Self::_ty();
47            self::internal::env_add(id.clone(), t.clone());
48            self::internal::env_id(id.clone(), t.clone());
49            self::internal::env_doc(id, Self::_ty_doc());
50            t
51        }
52    }
53    fn id() -> TypeId {
54        TypeId::of::<Self>()
55    }
56    fn _ty() -> Type;
57    fn _ty_doc() -> internal::TypeDoc {
58        internal::TypeDoc::default()
59    }
60    // only serialize the value encoding
61    fn idl_serialize<S>(&self, serializer: S) -> Result<(), S::Error>
62    where
63        S: Serializer;
64}
65
66pub trait Serializer: Sized {
67    type Error: Error;
68    type Compound: Compound<Error = Self::Error>;
69    fn serialize_bool(self, v: bool) -> Result<(), Self::Error>;
70    #[cfg_attr(docsrs, doc(cfg(feature = "bignum")))]
71    #[cfg(feature = "bignum")]
72    fn serialize_int(self, v: &crate::Int) -> Result<(), Self::Error>;
73    fn serialize_i128(self, v: i128) -> Result<(), Self::Error>;
74    #[cfg_attr(docsrs, doc(cfg(feature = "bignum")))]
75    #[cfg(feature = "bignum")]
76    fn serialize_nat(self, v: &crate::Nat) -> Result<(), Self::Error>;
77    fn serialize_u128(self, v: u128) -> Result<(), Self::Error>;
78    fn serialize_nat8(self, v: u8) -> Result<(), Self::Error>;
79    fn serialize_nat16(self, v: u16) -> Result<(), Self::Error>;
80    fn serialize_nat32(self, v: u32) -> Result<(), Self::Error>;
81    fn serialize_nat64(self, v: u64) -> Result<(), Self::Error>;
82    fn serialize_int8(self, v: i8) -> Result<(), Self::Error>;
83    fn serialize_int16(self, v: i16) -> Result<(), Self::Error>;
84    fn serialize_int32(self, v: i32) -> Result<(), Self::Error>;
85    fn serialize_int64(self, v: i64) -> Result<(), Self::Error>;
86    fn serialize_float32(self, v: f32) -> Result<(), Self::Error>;
87    fn serialize_float64(self, v: f64) -> Result<(), Self::Error>;
88    fn serialize_text(self, v: &str) -> Result<(), Self::Error>;
89    fn serialize_null(self, v: ()) -> Result<(), Self::Error>;
90    fn serialize_empty(self) -> Result<(), Self::Error>;
91    fn serialize_option<T>(self, v: Option<&T>) -> Result<(), Self::Error>
92    where
93        T: CandidType + ?Sized;
94    fn serialize_struct(self) -> Result<Self::Compound, Self::Error>;
95    fn serialize_vec(self, len: usize) -> Result<Self::Compound, Self::Error>;
96    fn serialize_blob(self, v: &[u8]) -> Result<(), Self::Error>;
97    fn serialize_variant(self, index: u64) -> Result<Self::Compound, Self::Error>;
98    fn serialize_principal(self, v: &[u8]) -> Result<(), Self::Error>;
99    fn serialize_function(self, v: &[u8], meth: &str) -> Result<(), Self::Error>;
100}
101
102pub trait Compound {
103    type Error;
104    fn serialize_element<T>(&mut self, v: &T) -> Result<(), Self::Error>
105    where
106        T: CandidType + ?Sized;
107    // Used for simulating serde(with = "serde_bytes"). We can remove this when specialization is stable in Rust,
108    // or generalize this function to take a closure for with.
109    #[doc(hidden)]
110    fn serialize_blob(&mut self, blob: &[u8]) -> Result<(), Self::Error>;
111    /// Write raw element bytes directly for a primitive vector.
112    /// Returns Ok(true) if written, Ok(false) if not supported (caller should use per-element fallback).
113    fn try_write_raw_elements(&mut self, _bytes: &[u8]) -> Result<bool, Self::Error> {
114        Ok(false)
115    }
116}
candid/types/mod.rs

candid/types/
mod.rs
