Function scale_discrete 

pub fn scale_discrete(
    aesthetic: &str,
    spec: &str,
    n: usize,
) -> Result<String, Error>

Emits a ggsql discrete scale clause using a discrete core palette.

This compatibility helper preserves its original ggsci-only error type. Use GgsqlPalette::to_scale_clause when aesthetic validation is required.

Errors

Returns any palette lookup or length error reported by ggsci. In particular, a continuous palette returns ggsci::Error::NotDiscretePalette.