// ============================================================================
// Anagram check — same multiset of letters
// ============================================================================
//
// Two strings are anagrams iff sorting their letters yields the same string.
// We lowercase, drop spaces, explode into a character list, sort it, and
// re-join. Demonstrates split/sort/join on character lists.
//
// Run: soma run anagram.cell --signal is_anagram "listen" "silent"

cell Anagram {
    face {
        signal canonical(s: String) -> String
        signal is_anagram(a: String, b: String) -> Bool
    }

    // Sorted, lowercased, space-free signature of a word.
    on canonical(s: String) {
        let low = replace(lowercase(s), " ", "")
        let chars = list()
        for i in range(0, len(low)) {
            chars = push(chars, low[i])
        }
        return join(chars.sort(), "")
    }

    on is_anagram(a: String, b: String) {
        return canonical(a) == canonical(b)
    }
}

cell test AnagramTest {
    rules {
        assert is_anagram("listen", "silent")
        assert is_anagram("triangle", "integral")
        assert is_anagram("Dormitory", "dirty room")
        assert !is_anagram("hello", "world")
        assert canonical("cab") == "abc"
    }
}