Struct FunctionDeclOrImpl

pub struct FunctionDeclOrImpl<'f> { /* private fields */ }

Union type representing either a function declaration or implementation.

FunctionDeclOrImpl can hold either:

• A function type signature (declaration) for compile-time type checking
• A concrete function implementation for runtime execution
• Both a declaration and implementation (preferred)

This allows the system to provide type information even when implementations are not available, enabling better compile-time checking and error reporting.

Examples

use cel_cxx::function::{FunctionDeclOrImpl, IntoFunction};
use cel_cxx::types::{ValueType, FunctionType};

// Create from declaration only
let func_type = FunctionType::new(ValueType::Int, vec![ValueType::Int]);
let decl_only = FunctionDeclOrImpl::new(func_type);

// Create from implementation (includes both decl and impl)
let func = (|a: i32, b: i32| -> i32 { a + b }).into_function();
let with_impl = FunctionDeclOrImpl::new_impl(func);

Implementations

impl<'f> FunctionDeclOrImpl<'f>

pub fn new_impl(impl: Function<'f>) -> Self

Creates a new FunctionDeclOrImpl from a function implementation.

This constructor creates both the declaration (extracted from the function’s type signature) and stores the implementation for runtime execution.

Arguments

• r#impl - The function implementation

Returns

New FunctionDeclOrImpl containing both declaration and implementation

pub fn new(type: FunctionType) -> Self

Creates a new FunctionDeclOrImpl from a function type declaration.

This constructor creates a declaration-only entry, useful for providing type information without requiring an implementation.

Arguments

• r#type - The function type signature

Returns

New FunctionDeclOrImpl containing only the declaration

pub fn is_impl(&self) -> bool

Returns whether this entry has a concrete implementation.

Returns

true if this entry contains a function implementation, false if declaration-only

pub fn decl(&self) -> &FunctionType

Gets the function type declaration.

Returns

Reference to the function type signature

pub fn impl(&self) -> Option<&Function<'f>>

Gets the function implementation, if available.

Returns

Some(&Function) if implementation is available, None for declaration-only entries

Trait Implementations

impl<'f> Clone for FunctionDeclOrImpl<'f>

fn clone(&self) -> FunctionDeclOrImpl<'f>

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<'f> Debug for FunctionDeclOrImpl<'f>

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

Formats the value using the given formatter.

impl FunctionTypeOverload for FunctionDeclOrImpl<'_>

fn arguments(&self) -> Vec<ValueType>

Returns the argument types for this function.