lib.rs

use std::collections::HashMap;

type CharCount = HashMap<char, u16>;

fn word_to_hashmap(word: &str) -> CharCount {
    let mut charcount = HashMap::new();
    for c in word.chars() {
        let c = c.to_lowercase().next().unwrap();
        let count = charcount.entry(c).or_insert(0);
        *count += 1;
    }
    charcount
}

pub fn anagrams_for<'a>(word: &str, inputs: &'a [&str]) -> Vec<&'a str> {
    let mut outputs: Vec<&'a str> = vec![];
    let wordhash = word_to_hashmap(word);
    
    for i in inputs.iter() {
        if i.to_lowercase() == word.to_lowercase() { continue }
        
        if wordhash == word_to_hashmap(i) {
            outputs.push(i);
        }
    }
    outputs
}