Struct BoxConditionalStatefulFunction 

pub struct BoxConditionalStatefulFunction<T, R> { /* private fields */ }

BoxConditionalStatefulFunction struct

A conditional function that only executes when a predicate is satisfied. Uses BoxStatefulFunction and BoxPredicate for single ownership semantics.

This type is typically created by calling BoxStatefulFunction::when() and is designed to work with the or_else() method to create if-then-else logic.

Features

• Single Ownership: Not cloneable, consumes self on use
• Conditional Execution: Only maps when predicate returns true
• Chainable: Can add or_else branch to create if-then-else logic
• Implements StatefulFunction: Can be used anywhere a StatefulFunction is expected

Examples

use prism3_function::{StatefulFunction, BoxStatefulFunction};

let mut high_count = 0;
let mut low_count = 0;

let mut function = BoxStatefulFunction::new(move |x: i32| {
    high_count += 1;
    x * 2
})
.when(|x: &i32| *x >= 10)
.or_else(move |x| {
    low_count += 1;
    x + 1
});

assert_eq!(function.apply(15), 30); // when branch executed
assert_eq!(function.apply(5), 6);   // or_else branch executed

Author

Haixing Hu

Implementations

impl<T, R> BoxConditionalStatefulFunction<T, R>

where T: 'static, R: 'static,

pub fn or_else<F>(self, else_function: F) -> BoxStatefulFunction<T, R>

where F: StatefulFunction<T, R> + 'static,

Provides an alternative function for when the predicate is not satisfied

Combines the current conditional function with an alternative function into a new function that implements the following semantics:

When the returned function is called with an argument:

• If the predicate is satisfied, it executes the internal function
• If the predicate is NOT satisfied, it executes the alternative function

Parameters

• else_function - The alternative function to execute when predicate fails

Returns

Returns a new function that handles both conditional branches

Examples

let func = BoxFunction::new(|x: i32| x * 2);
let alternative = BoxFunction::new(|x: i32| x + 10);

let conditional = func.when(|x| *x > 0).or_else(alternative);

assert_eq!(conditional.apply(5), 10);  // 5 * 2 = 10
assert_eq!(conditional.apply(-3), 7);  // -3 + 10 = 7

Trait Implementations

impl<T, R> Debug for BoxConditionalStatefulFunction<T, R>

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

Formats the value using the given formatter.

impl<T, R> Display for BoxConditionalStatefulFunction<T, R>

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

Formats the value using the given formatter.