fn starts_with()

in crates/iceberg/src/expr/visitors/manifest_evaluator.rs [244:285]
37 lines of code
7 McCabe index (conditional complexity)

    fn starts_with(
        &mut self,
        reference: &BoundReference,
        datum: &Datum,
        _predicate: &BoundPredicate,
    ) -> crate::Result<bool> {
        let field = self.field_summary_for_reference(reference);

        if field.lower_bound.is_none() || field.upper_bound.is_none() {
            return ROWS_CANNOT_MATCH;
        }

        let prefix = ManifestFilterVisitor::datum_as_str(
            datum,
            "Cannot perform starts_with on non-string value",
        )?;
        let prefix_len = prefix.len();

        if let Some(lower_bound) = &field.lower_bound {
            let lower_bound_str = ManifestFilterVisitor::datum_as_str(
                lower_bound,
                "Cannot perform starts_with on non-string lower bound",
            )?;
            let min_len = lower_bound_str.len().min(prefix_len);
            if prefix.as_bytes().lt(&lower_bound_str.as_bytes()[..min_len]) {
                return ROWS_CANNOT_MATCH;
            }
        }

        if let Some(upper_bound) = &field.upper_bound {
            let upper_bound_str = ManifestFilterVisitor::datum_as_str(
                upper_bound,
                "Cannot perform starts_with on non-string upper bound",
            )?;
            let min_len = upper_bound_str.len().min(prefix_len);
            if prefix.as_bytes().gt(&upper_bound_str.as_bytes()[..min_len]) {
                return ROWS_CANNOT_MATCH;
            }
        }

        ROWS_MIGHT_MATCH
    }