use crate::logical_plan::consumer::{
SubstraitConsumer, field_from_substrait_type_without_names,
};
use datafusion::common::{DFSchema, substrait_err};
use datafusion::logical_expr::{Cast, Expr, TryCast};
use substrait::proto::expression as substrait_expression;
use substrait::proto::expression::cast::FailureBehavior::ReturnNull;
pub async fn from_cast(
consumer: &impl SubstraitConsumer,
cast: &substrait_expression::Cast,
input_schema: &DFSchema,
) -> datafusion::common::Result<Expr> {
match cast.r#type.as_ref() {
Some(output_type) => {
let input_expr = Box::new(
consumer
.consume_expression(
cast.input.as_ref().unwrap().as_ref(),
input_schema,
)
.await?,
);
let field = field_from_substrait_type_without_names(consumer, output_type)?;
if cast.failure_behavior() == ReturnNull {
Ok(Expr::TryCast(TryCast::new_from_field(input_expr, field)))
} else {
Ok(Expr::Cast(Cast::new_from_field(input_expr, field)))
}
}
None => substrait_err!("Cast expression without output type is not allowed"),
}
}