datafusion_substrait::logical_plan::producer

Function to_substrait_extended_expr

Source 
pub fn to_substrait_extended_expr(
    exprs: &[(&Expr, &Field)],
    schema: &DFSchemaRef,
    state: &SessionState,
) -> Result<Box<ExtendedExpression>>
Expand description

Serializes a collection of expressions to a Substrait ExtendedExpression message

The ExtendedExpression message is a top-level message that can be used to send expressions (not plans) between systems.

Each expression is also given names for the output type. These are provided as a field and not a String (since the names may be nested, e.g. a struct). The data type and nullability of this field is redundant (those can be determined by the Expr) and will be ignored.

Substrait also requires the input schema of the expressions to be included in the message. The field names of the input schema will be serialized.