Migrate arrow_cast to a UDF
#9610
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Co-authored-by: Andrew Lamb <andrew@nerdnetworks.org>
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arrow_cast to a UDF
| "| 2020-09-04 |", | ||
| "+------------+", | ||
| "+-----------------------------------+", | ||
| "| arrow_cast(t.values,Utf8(\"Utf8\")) |", |
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These differences are due to the fact that arrow_cast is just a normal function now rather than a special case in the parser. Thus the naming reflects normal function naming
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Interesting I got stuck implementing the simpliy function because I thought it should convert arrow_cast(t.values,Utf8(\"Utf8\")) to t.values and other similar cases as well.
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Yeah -- this is pretty tricky. arrow_cast was quite special in the parser, so now that it is handled like a normal function it has the same (somewhat strange) function effect of column naming
| info: &dyn SimplifyInfo, | ||
| ) -> Result<ExprSimplifyResult> { | ||
| // convert this into a real cast | ||
| let target_type = data_type_from_args(&args)?; |
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This simplify logic mirrors the previous behavior in that arrow_cast is replaced with a normal cast
| } | ||
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| fn return_type(&self, arg_types: &[DataType]) -> Result<DataType> { | ||
| parse_data_type(&arg_types[1].to_string()) |
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If return_type_from_exprs exists, we don't need return_type. Is it better to return err or panic here?
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This is an excellent call -- changed to internal_err in 0c7b7be
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Thanks again @brayanjuls and @jayzhan211 |
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Which issue does this PR close?
Closes #9143
Closes #9287
Closes #9298
Rationale for this change
arrow_cast function migration.
What changes are included in this PR?
This PR is based on #9298 from @brayanjuls, updated to use the new simplify API.
Are these changes tested?
Yes, by existing tests
Are there any user-facing changes?