限(かぎ)りAs long as, While… is the case, Limited to

に限る and 限り both relate to boundaries or constraints, but serve different functions. に限る expresses the speaker's judgment that something is the best or most suitable, e.g. '寒い日は鍋に限る' ('Nothing beats hot pot on a cold day'). 限り sets a condition or scope, meaning 'as long as' or 'while', e.g. '知っている限り' ('as far as I know').

Both express conditional relationships but with different focus. からには conveys cause-and-effect or obligation, as in 約束したからには守るべきだ (Since I made a promise, I should keep it). 限り emphasizes temporal or situational boundaries, meaning as long as or while, as in 生きている限り希望はある (As long as you live, there is hope).

Both expressions can be translated as 'as long as (A)', but they differ in nuance. さえ〜ば indicates that a single condition is sufficient, e.g. 努力さえすればうまくいく ('As long as you try, things will go well'). 限り means 'as long as' in the sense of duration or ongoing state, e.g. 生きている限り夢を追いたい ('As long as I live, I want to chase my dream').

These two expressions derived from 限る contrast in meaning. とは限らない expresses that something is not necessarily the case, e.g. '雨だからといって中止とは限らない' ('Just because it's raining doesn't mean it will be canceled'). 限り indicates a bounded condition or extent, e.g. '知っている限り' ('as far as I know').