use std::result;

use crate::schema::FieldEntry;

/// `FastFieldNotAvailableError` is returned when the
/// user requested for a fast field reader, and the field was not
/// defined in the schema as a fast field.
#[derive(Debug, Error)]
#[error("Fast field not available: '{field_name:?}'")]
pub struct FastFieldNotAvailableError {
    pub(crate) field_name: String,
}

impl FastFieldNotAvailableError {
    /// Creates a `FastFieldNotAvailable` error.
    /// `field_entry` is the configuration of the field
    /// for which fast fields are not available.
    pub fn new(field_entry: &FieldEntry) -> FastFieldNotAvailableError {
        FastFieldNotAvailableError {
            field_name: field_entry.name().to_string(),
        }
    }
}

/// Result when trying to access a fast field reader.
pub type Result<R> = result::Result<R, FastFieldNotAvailableError>;