Function writeBit

src/simplicity/frame.h:80–90

Given a write frame, set its cursor's cell to 'bit' and advance the cursor by one cell. * Cells in front of the cursor's final position may be overwritten. * * The function returns the same value as bit. This facilitates using 'writeBit' within an 'if' statement * * if (writeBit(frame, bit)) { ... } else { ... } * * so that one can both decide conditions based on a Boolean value while

 * Precondition: '*frame' is a valid write frame for 1 more cell.
 */
static inline bool writeBit(frameItem* frame, bool bit) {
  simplicity_debug_assert(0 < frame->offset);
  frame->offset--;
  UWORD* dst_ptr = frame->edge + frame->offset / UWORD_BIT;
  if (bit) {
    *dst_ptr |= (UWORD)((UWORD)1 << (frame->offset % UWORD_BIT));
  } else {
    *dst_ptr = LSBclear(*dst_ptr, frame->offset % UWORD_BIT + 1);
  }
  return bit;
}

/* Given a read frame, advance the cursor by 'n' cells.
 *