Parameters for define statements

[mtoy-googly-moogly]

Parameter MVP

Parameterized explorables which can have required parameters, or optional parameters with default values.

Progress

• Decide on provisional syntax
• parameter declarations parsed to IR
• Value parameter references parsed to IR
• Condition Value parameters parsed to IR
• Parse invocation syntax to IR
• Implement reference to condition parameters
• Generate SQL for expressions with parameters
• Write some model/ tests for the generated SQL
• Translation API reflects missing parameters and can parse an expression provided
• Parameters inside of joins, paths
• Reject expressions which are not compatible with parameters
• Figure out what to do about @lloydtabb request for the gesture "users of this explore must provide some filter, any filter with a left hand side for this field"
• Some syntax for a required filter which means "do not filter"

Syntax

• Declaration

    define thingWithParams(
      has reqCondition : timestamp
      has optCondition : timestamp or @1960 to @1970
      has reqValue timestamp
      has optValue timestamp or @2001-09-11
      has constValue @1969-07-20 12:56
      ) is ('project.schema.tableName'
        ...
      

• usage

flightsFiltered (departureFilter is @2003) | by_carrier