parsing intersect and except
#271
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As per our discussion, we need tests to make sure that we're parsing with the correct operator precedence. ( |
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This is clever but might be confusing for someone without context. It might be helpful to give an example like {1,2} ∩ {2,3} U {3,4} has two results depending on whether you execute the intersect or union first (same as addition/multiplication). Here is 3 sentences that make it clear how we enforce INTERSECT being executed before UNION/EXCEPT...
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Agreed. It's clever but I'm still not entire sure I understand how it works. Some documentation would be really helpful.
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would it be dumb to rewrite this into "SetOpType" and distinct as a bool? or does that lose information
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Not dumb, and it doesn't lose any information.
I just duplicated the existing logic; I'm pretty sure it was written that way in the first place so the yacc code is simpler.
Could just do
$$ = UnionStr
$$ = UnionAllStr
$$ = UnionDistinctStrand convert it later instead of returning a new struct
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| func (*Union) iStatement() {} |
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Looks like the whitespace got messed up in this file.
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Agreed. It's clever but I'm still not entire sure I understand how it works. Some documentation would be really helpful.
3 participants
This PR adds support for parsing the keywords
INTERSECTandEXCEPT.These work similar to
UNIONand work withDISTINCTandALLkeywords.Additionally, there are new precedence tests;
INTERSECThas a higher precedence thanUNIONandEXCEPT.The rest are parsed left to right.
syntax for dolthub/dolt#6643