reflect - [devnet]

Functionality for reflection in Move.

use 0x1::features;
use 0x1::result;
use 0x1::string;

Enum ReflectionError

Represents errors returned by the reflection API. TODO: make this public once language version 2.4 is available

enum ReflectionError has copy, drop, store

Variants

InvalidIdentifier

Fields

FunctionNotFound

Fields

FunctionNotAccessible

Fields

FunctionIncompatibleType

Fields

FunctionNotInstantiated

Fields

Constants

This error indicates that the reflection feature is not enabled.

const E_FEATURE_NOT_ENABLED: u64 = 0;

Functions

resolve

Resolves a function specified by address and symbolic name, with expected type, into a typed function value.

Example usage:

let fn : |address|u64 has store = reflect::resolve(@somewhere, utf8(b"mod"), utf8(b"fn")).unwrap();
assert!(fn(my_addr) == some_value)

See ReflectionError for the possible errors which can result. On successful resolution, a function value is returned which can be safely used in future executions as indicated by the requested type.

In order to be accessible, the resolved function must be public. This prevents reflection to work around the languages modular encapsulation guarantees.

The resolved function can be generic, in which case the instantiation must be inferrible from the provided FuncType. For example, public fun foo<T>(T), with FunType = |u64|, T = u64 can be derived. If not all type parameters can be inferred, an error will be produced.

public fun resolve<FuncType>(addr: address, module_name: &string::String, func_name: &string::String): result::Result<FuncType, reflect::ReflectionError>

Implementation

public fun resolve<FuncType>(
    addr: address, module_name: &String, func_name: &String
): Result<FuncType, ReflectionError> {
    assert!(
        features::is_function_reflection_enabled(),
        error::invalid_state(E_FEATURE_NOT_ENABLED)
    );
    native_resolve(addr, module_name, func_name)
}

error_code

Returns numerical code associated with error.

public fun error_code(self: reflect::ReflectionError): u64

Implementation

public fun error_code(self: ReflectionError): u64 {
    match(self) {
        InvalidIdentifier => 0,
        FunctionNotFound => 1,
        FunctionNotAccessible => 2,
        FunctionIncompatibleType => 3,
        FunctionNotInstantiated => 4
    }
}

native_resolve

fun native_resolve<FuncType>(addr: address, module_name: &string::String, func_name: &string::String): result::Result<FuncType, reflect::ReflectionError>

Implementation

native fun native_resolve<FuncType>(
    addr: address, module_name: &String, func_name: &String
): Result<FuncType, ReflectionError>;

Specification

resolve

public fun resolve<FuncType>(addr: address, module_name: &string::String, func_name: &string::String): result::Result<FuncType, reflect::ReflectionError>

pragma verify = false;
pragma opaque;