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|
use crate::{
selection::{Selection, SelectionError},
state::{EditorState, EvaluationResult, GroupedChangeError},
};
pub enum EvaluationStrategy {
Sequential,
Grouped,
}
#[derive(Debug)]
pub enum EvaluationError {
Selection(SelectionError),
GroupedChange(GroupedChangeError),
}
impl From<SelectionError> for EvaluationError {
fn from(err: SelectionError) -> Self {
EvaluationError::Selection(err)
}
}
impl From<GroupedChangeError> for EvaluationError {
fn from(err: GroupedChangeError) -> Self {
EvaluationError::GroupedChange(err)
}
}
pub struct EditorStateMonad {
func: Box<dyn Fn(&EditorState) -> EvaluationResult>,
}
impl EditorStateMonad {
pub fn new(f: impl Fn(&EditorState) -> EvaluationResult + 'static) -> Self {
Self { func: Box::new(f) }
}
pub fn run(&self, state: &EditorState) -> EvaluationResult {
(self.func)(state)
}
pub fn run_with_strategy(
monads: Vec<EditorStateMonad>,
strategy: EvaluationStrategy,
state: &mut EditorState,
) -> Result<Selection, EvaluationError> {
match strategy {
EvaluationStrategy::Sequential => {
let mut last_selection = Selection::empty();
for monad in monads {
let (sel, state_changes) = monad.run(state);
state.commit_changes(state_changes);
last_selection = sel;
}
Ok(last_selection)
}
EvaluationStrategy::Grouped => {
let mut arms = Vec::new();
let mut all_selections = Vec::new();
for monad in monads {
let (sel, state_changes) = monad.run(state);
all_selections.push(sel);
arms.push(state_changes);
}
state.commit_changes_grouped(arms)?;
Ok(Selection::union(all_selections)?)
}
}
}
}
|
