Business Context
An ETL pipeline handles raw retail data which often contains missing values (nulls) and inconsistent data types (strings mixed with numbers). A developer is debugging a failure in a downstream calculation action. They use `echo` to inspect exactly how the CAS server interprets a heterogeneous list containing NaNs, nulls, and mixed types before it reaches the logic layer.
Data Preparation
No external data needed; internal variable testing.
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| 1 | /* No |
| 2 | Data Step required for this variable inspection test */ |
Étapes de réalisation
1
Define a list with Edge Cases: Nulls, missing values, and mixed types.
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| 1 | |
| 2 | PROC CAS; |
| 3 | |
| 4 | mixedList = {10, "StringValue", ., {nested=1}, .M}; |
| 5 | |
| 6 | |
| 7 | RUN; |
| 8 |
2
Execute echo to visualize the internal representation of missing values.
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| 1 | PROC CAS; |
| 2 | mixedList = {10, "StringValue", ., {nested=1}, .M}; |
| 3 | BUILTINS.echo / debug_data=mixedList; |
| 4 | RUN; |
Expected Result
The log displays the list structure, clearly distinguishing between standard missing numeric values (.) and special missing values (.M), proving that the parameter parsing logic preserves these nuances.