contains.js

contains.js

const contains = (s1, s2) => (
    ((letn) => (
        letn(
            [
                [...s1], 
                [...s2],
            ],
            (a1, a2) => Boolean(
                a1.reduce((a, c, i) => (
                    (a) 
                    || (
                        (c === a2[0]) 
                        && (
                            letn(
                                [
                                    a1.reduce((r, e, ii) => (
                                        (
                                            (
                                                (ii >= i) 
                                                && ((ii) < (i + a2.length))
                                            ) 
                                                ? ([...r, e]) 
                                                : (r)
                                        ) 
                                    ), [])
                                ],
                                (a11) => (
                                    a11.reduce(
                                        (r, c, i) => (
                                            ((r) && (c == a2[i]))
                                        ), 
                                        (a11.length === a2.length)
                                    )
                                ),
                            )
                        )
                    )
                ), false) 
            ),
        )
    ))
    ((v, c) => c(...v))
);