Renaming of bit_magic about sdsl-lite

[mpetri]

I have been thinking about this some more after our discussion. If I were to read a piece of code that uses bits::sel() or bit_magic::i1BP() and I'm not very familiar with the library I would not necessarily know what the function does.

the same goes for bits::lo and bits::hi. I understand that these function would make the code very concise and neat looking. but would probably require another comment above the line to explain what it does. for example

/* return the position in the final word */ return bits::sel(x,i);

is less descriptive and requires a comment compared to

return bits::selectWord(x,i) or something similar.

the same case could be made for a few other functions. for example bits::cnt could be renamed to bits::count or similar.

another example might potentially be the size() function. I realize that this is a standard c++ container requirement but in succinct data structure land kind of implies the "space usage" not the length especially since there are no real "space usage" functions in the int vector class. the cheat sheet will probably help to point to the "get_size_in_bytes() functions. (maybe also remove the unnecessary get_ prefix here?)

[simongog]

• have removed the get_ prefix in get_size... methods.
• we stay with bits::cnt, bits::sel, bits::lo, bits::hi, since selectWord also don't tell unexperienced users what is done. All renamed methods are also explained on the cheat sheet so that no comments are necessary in the client source.