Enum magnus::block::YieldValues

pub enum YieldValues<I> {
    Iter(I),
    Enumerator(Enumerator),
}

Helper type for functions that either yield multiple values to a block or return an Enumerator.

I must implement Iterator<Item = T>, where T implements ArgList.

Examples

use magnus::{
    block::{block_given, YieldValues},
    define_global_function, eval, method,
    prelude::*,
    rb_assert, RArray, Value,
};

fn count_to_3_abc(rb_self: Value) -> YieldValues<impl Iterator<Item = (u8, char)>> {
    if block_given() {
        YieldValues::Iter((1..=3).zip('a'..='c'))
    } else {
        YieldValues::Enumerator(rb_self.enumeratorize("count_to_3_abc", ()))
    }
}

define_global_function("count_to_3_abc", method!(count_to_3_abc, 0));

// call Ruby method with a block.
let a = RArray::new();
rb_assert!("count_to_3_abc {|i, c| a << [i, c]} == nil", a);
rb_assert!(r#"a == [[1, "a"], [2, "b"], [3, "c"]]"#, a);

// call Ruby method without a block.
let enumerator: Value = eval("count_to_3_abc").unwrap();

rb_assert!(r#"enumerator.next == [1, "a"]"#, enumerator);
rb_assert!(r#"enumerator.next == [2, "b"]"#, enumerator);

Variants

Iter(I)

Yields I::Item to given block.

Enumerator(Enumerator)

Returns Enumerator from the method.