basic murmur hash function

Sure! Here's an implementation of the MurmurHash function in BASIC:

FUNCTION MurmurHash3_x86_32(key AS STRING, seed AS INTEGER) AS INTEGER
    CONST c1 = &HCC9E2D51
    CONST c2 = &H1B873593
    CONST r1 = 15
    CONST r2 = 13
    CONST m = &H5BD1E995
    CONST n = 0xE6546B64

    DIM h AS INTEGER = seed
    DIM k AS INTEGER

    FOR i = 1 TO LEN(key) STEP 4
        k = ASC(MID(key, i, 1)) OR (ASC(MID(key, i + 1, 1)) << 8) OR (ASC(MID(key, i + 2, 1)) << 16) OR (ASC(MID(key, i + 3, 1)) << 24)
        k = (k * c1) AND &HFFFFFFFF
        k = (k << r1) OR ((k >> (32 - r1)) AND &HFFFFFFFF)
        k = (k * c2) AND &HFFFFFFFF

        h = (h XOR k)
        h = (h << r2) OR ((h >> (32 - r2)) AND &HFFFFFFFF)
        h = ((h * m) + n) AND &HFFFFFFFF
    NEXT

    h = h XOR LEN(key)
    h = h XOR (h >> 16)
    h = (h * &H85EBCA6B) AND &HFFFFFFFF
    h = h XOR (h >> 13)
    h = (h * &HC2B2AE35) AND &HFFFFFFFF
    h = h XOR (h >> 16)

    RETURN h
END FUNCTION

This implementation of the MurmurHash3_x86_32 function takes a key (as a string) and a seed (as an integer) as input. It then iterates over the key in chunks of 4 characters, converting each chunk to a 32-bit integer. The algorithm applies a series of bitwise operations and multiplications to the integer, XORing it with a hash value and updating the hash value accordingly.

Finally, the hash value is XORed with the length of the key and undergoes a series of additional bitwise operations and multiplications to produce the final hash value, which is then returned.

This implementation is based on the 32-bit version of the MurmurHash3 algorithm, which is commonly used for hash-based algorithms and data structures.

I hope this code snippet helps! Let me know if you have any further questions.