Ruby makes a number of tradeoffs in favor of "expressibility" at the expense of readability (without a _high_ degree of ruby proficiency) and ability to reason about programs. You can disagree with these tradeoffs, but they're not mistakes. It also has some things which might be designed differently if the language started from scratch (e.g. string encoding), but I would still say its a stretch to call these mistakes.
Ruby also has a number of things which make it "hard" (some would say impossible) to create fully equivalent alternative implementations. This is suboptimal, but it is what it is; at this point the level of change required to make it amiable to alternative implementation would be...prohibitive.
I do agree, however, that the inline rescue with no ability to limit to anything other than StandardError was a mistake...I've just seen way too many cases where _far_ more than reasonable got caught. That said, I'm not sure there would be any great way to add matching on the inline rescue to the grammar -- I think it would have to be removed.
Ruby also has a number of things which make it "hard" (some would say impossible) to create fully equivalent alternative implementations. This is suboptimal, but it is what it is; at this point the level of change required to make it amiable to alternative implementation would be...prohibitive.
I do agree, however, that the inline rescue with no ability to limit to anything other than StandardError was a mistake...I've just seen way too many cases where _far_ more than reasonable got caught. That said, I'm not sure there would be any great way to add matching on the inline rescue to the grammar -- I think it would have to be removed.