graphrecords-query 0.5.0

use crate::{
    Bare, BareValueDomain, ExpandedChild, ExpandedIndex, Explain, Failure, IndexDomain, Indexed,
    Labeled, Operand, Ordered, Positional, QueryResult,
    capabilities::StringValue,
    element::{Expanding, Pipeline, Retention},
    error::string::EmptySplitDelimiter,
    execution::EvaluationCache,
    operations::{
        Apply, ArgumentSource, ElementKernel, ElementPipeline, Keyed, Operation, OperationContext,
        Prepare, Unaligned,
    },
    optimizer::{OperationInputs, OptimizerHints, PlanIdentity, PlanInputs},
    registry::operation_manifest,
    traits::Split,
};
use graphrecords_core::GraphRecord;

#[derive(Clone, Explain, Operation, OperationInputs, OptimizerHints, PlanIdentity, PlanInputs)]
#[operation(scope = Element)]
#[explain(label = "Split")]
#[plan(optimizer_hints(empty = if_all))]
pub struct SplitOperation<A> {
    #[argument]
    delimiter: A,
}

impl<A: Prepare> Prepare for SplitOperation<A> {
    type Prepared<'a>
        = A::Prepared<'a>
    where
        Self: 'a;

    fn prepare<'a>(
        &'a self,
        graphrecord: &'a GraphRecord,
        cache: &'a EvaluationCache<'a>,
    ) -> QueryResult<Self::Prepared<'a>> {
        self.delimiter.prepare(graphrecord, cache)
    }
}

impl<I, V, A> ElementKernel<Indexed<I, V>> for SplitOperation<A>
where
    I: IndexDomain,
    V: StringValue,
    A: ArgumentSource<Keyed<I>>,
    A::ValueDomain: StringValue,
{
    type Emission = Expanding<Ordered>;
    type OutShape = Indexed<ExpandedIndex<I, Positional>, V>;

    fn pipeline<'a>(
        _graphrecord: &'a GraphRecord,
        prepared: Self::Prepared<'a>,
    ) -> QueryResult<ElementPipeline<'a, Indexed<I, V>, Self>> {
        Ok(Pipeline::keyed(move |index, value: V::Value<'a>| {
            let role = value.clone();
            let value =
                V::into_string(Self::LABEL, value).map_err(|failure| failure.at::<I>(&index))?;
            let delimiter = match A::Retention::collapse(A::resolve(&prepared, &index, Self::LABEL))
            {
                None => return Ok(Vec::new()),
                Some(Err(failure)) => return Err(failure),
                Some(Ok(delimiter)) => A::ValueDomain::into_string(Self::LABEL, delimiter)
                    .map_err(|failure| failure.at::<I>(&index))?,
            };

            if delimiter.is_empty() {
                return Err(Failure::new_at::<I, _>(
                    Self::LABEL,
                    EmptySplitDelimiter,
                    &index,
                ));
            }

            Ok(value
                .split(&delimiter)
                .enumerate()
                .map(|(position, fragment)| {
                    ExpandedChild::success(position, V::from_string(&role, fragment.to_owned()))
                })
                .collect())
        }))
    }
}

impl<V, A> ElementKernel<Bare<V>> for SplitOperation<A>
where
    V: StringValue + BareValueDomain,
    A: ArgumentSource<Unaligned>,
    A::ValueDomain: StringValue,
{
    type Emission = Expanding<Ordered>;
    type OutShape = Bare<V>;

    fn pipeline<'a>(
        _graphrecord: &'a GraphRecord,
        prepared: Self::Prepared<'a>,
    ) -> QueryResult<ElementPipeline<'a, Bare<V>, Self>> {
        Ok(Pipeline::new(move |outcome: QueryResult<V::Value<'a>>| {
            let (role, value) = match outcome {
                Err(failure) => return vec![Err(failure)],
                Ok(value) => {
                    let role = value.clone();
                    match V::into_string(Self::LABEL, value) {
                        Ok(value) => (role, value),
                        Err(failure) => return vec![Err(failure)],
                    }
                }
            };
            let delimiter = match A::Retention::collapse(A::resolve(&prepared, &(), Self::LABEL)) {
                None => return Vec::new(),
                Some(Err(failure)) => return vec![Err(failure)],
                Some(Ok(delimiter)) => match A::ValueDomain::into_string(Self::LABEL, delimiter) {
                    Ok(delimiter) => delimiter,
                    Err(failure) => return vec![Err(failure)],
                },
            };

            if delimiter.is_empty() {
                return vec![Err(Failure::new(Self::LABEL, EmptySplitDelimiter))];
            }

            value
                .split(&delimiter)
                .map(|fragment| Ok(V::from_string(&role, fragment.to_owned())))
                .collect()
        }))
    }
}

impl<O, A> Split<A> for O
where
    SplitOperation<A>: Operation,
    O: Apply<SplitOperation<A>>,
{
    type ReturnOperand = O::Output;

    fn split(&self, delimiter: A) -> Self::ReturnOperand {
        Self::ReturnOperand::new(OperationContext::new(
            self.clone(),
            SplitOperation { delimiter },
        ))
    }
}

operation_manifest! {
    SplitOperation<A> {
        method: Split<A>::split;
        scope: element;

        kernel {
            parameters: <I: IndexDomain, V: StringValue>;
            argument: A: ArgumentSource<Keyed<I>> where A::ValueDomain: StringValue;
            input: Indexed<I, V>;
            output: Indexed<ExpandedIndex<I, Positional>, V>;
            emission: Expanding<Ordered>;
        }
        kernel {
            parameters: <V: StringValue + BareValueDomain>;
            argument: A: ArgumentSource<Unaligned> where A::ValueDomain: StringValue;
            input: Bare<V>;
            output: Bare<V>;
            emission: Expanding<Ordered>;
        }
    }
}