What is the meaning of so far?

adverb

• Used in negative statement to describe a situation that has existed up to this point or up to the present time.
  • usage: "So far he hasn't called"; "the sun isn't up yet"
  • synonyms: thus far, up to now, hitherto, heretofore, as yet, yet, til now, until now
• To the degree or extent that.
  • usage: "insofar as it can be ascertained, the horse lung is comparable to that of man"; "so far as it is reasonably practical he should practice restraint"
  • synonyms: insofar, in so far, to that extent, to that degree
• Used after a superlative.
  • usage: "this is the best so far"; "the largest drug bust yet"
  • synonyms: yet