Macro indefinite_article_only 

macro_rules! indefinite_article_only {
    ($word:literal) => { ... };
    ($($word:literal),+) => { ... };
}

Returns only the article related to the first word (also accepts a list of input string)

Examples

use indefinite::indefinite_article_only;

assert_eq!(indefinite_article_only!("apple"), "an");
assert_eq!(indefinite_article_only!("apple","pear"), ["an", "a"]);