— procedure: bit-string-fill! bit-string initialization

Fills bit-string with zeroes if initialization is #f; otherwise fills bit-string with ones. Returns an unspecified value.

— procedure: bit-string-move! target-bit-string bit-string

Moves the contents of bit-string into target-bit-string. Both arguments must be bit strings of the same length. The results of the operation are undefined if the arguments are the same bit string.

— procedure: bit-substring-move-right! bit-string-1 start1 end1 bit-string-2 start2

Destructively copies the bits of bit-string-1, starting at index start1 (inclusive) and ending at end1 (exclusive), into bit-string-2 starting at index start2 (inclusive). Start1 and end1 must be valid substring indices for bit-string-1, and start2 must be a valid index for bit-string-2. The length of the source substring must not exceed the length of bit-string-2 minus the index start2.

The bits are copied starting from the MSB and working towards the LSB; the direction of copying only matters when bit-string-1 and bit-string-2 are eqv?.