Allow Iterator.stop to be used inside Iterator.of block #4208
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| private def self.without_stop(&block : -> T) | ||
| e = block.call | ||
| raise "" if e.is_a?(Iterator::Stop) |
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This method isn't called, only used for typeof.
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Oh, I see. Still, raise "" (which internally translates to raise ArgumentError.new, no?) looks odd for me...
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No, raise "" = raise Exception.new
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So, why no raise Exception.new? Seems imo clearer.
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We just need a function that returns NoReturn. The same raise "" pattern is used in https://github.com/crystal-lang/crystal/blob/master/src/iterator.cr#L472 .
The code is never executed actually.
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Fair 'nuff, I just thought it looks odd aside of its actual function.
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We could find probably a more idiomatic way to express this. maybe a fail : NoReturn or halt or unreachable that will abort compilation at codegen but will return NoReturn in semantic could work better. #someday
Ref #4198 (comment)
Before PR using
Iterator.stopin the block given toIterator.ofwould generate a union between the expected type andIterator::Stop.