spark技术分享UnaryExpression Contract
UnaryExpression is…FIXME
defineCodeGen Method
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defineCodeGen( ctx: CodegenContext, ev: ExprCode, f: String => String): ExprCode |
defineCodeGen…FIXME
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Note
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defineCodeGen is used when…FIXME
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nullSafeEval Method
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nullSafeEval(input: Any): Any |
nullSafeEval simply fails with the following error (and is expected to be overrided to save null-check code):
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UnaryExpressions must override either eval or nullSafeEval |
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Note
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nullSafeEval is used exclusively when UnaryExpression is requested to eval.
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Evaluating Expression — eval Method
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eval(input: InternalRow): Any |
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Note
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eval is part of Expression Contract for the interpreted (non-code-generated) expression evaluation, i.e. evaluating a Catalyst expression to a JVM object for a given internal binary row.
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eval…FIXME
