substrait-expr 0.2.3

Utilities for working with Substrait expressions
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use crate::error::{Result, SubstraitExprError};

/// Helper trait for extracting a property that should always be present
/// from a protobuf message and returning an error if it is not
pub(crate) trait HasRequiredProperties<T> {
    fn into_required(self, prop_name: &str) -> Result<T>;
}

impl<T> HasRequiredProperties<T> for Option<T> {
    // TODO: Is there any better way to do this that doesn't require specifying prop_name?
    // Maybe a macro of some kind?
    fn into_required(self, prop_name: &str) -> Result<T> {
        self.ok_or_else(|| {
            SubstraitExprError::InvalidSubstrait(format!(
                "The required property {} is missing",
                prop_name
            ))
        })
    }
}

/// Helper trait for extracting a property that should always be present
/// from a protobuf message and returning an error if it is not
pub(crate) trait HasRequiredPropertiesRef<T> {
    fn required(&self, prop_name: &str) -> Result<&T>;
}

impl<T> HasRequiredPropertiesRef<T> for Option<T> {
    fn required(&self, prop_name: &str) -> Result<&T> {
        self.as_ref().ok_or_else(|| {
            SubstraitExprError::InvalidSubstrait(format!(
                "The required property {} is missing",
                prop_name
            ))
        })
    }
}