reconcile/src/raw_operation.rs

74 lines
2.5 KiB
Rust

use std::fmt::Debug;
use crate::{tokenizer::token::Token, utils::myers_diff::myers_diff};
/// Text editing operation containing the affected tokens.
///
/// `RawOperation`s can be joined together when the underlying tokens
/// allow for joining subsequent operations.
#[derive(Debug, Clone, PartialEq)]
pub enum RawOperation<T>
where
T: PartialEq + Clone + Debug,
{
Insert(Vec<Token<T>>),
Delete(Vec<Token<T>>),
Equal(Vec<Token<T>>),
}
impl<T> RawOperation<T>
where
T: PartialEq + Clone + Debug,
{
pub fn vec_from(left: &[Token<T>], right: &[Token<T>]) -> Vec<Self> { myers_diff(left, right) }
pub fn tokens(&self) -> &[Token<T>] {
match self {
RawOperation::Insert(tokens)
| RawOperation::Delete(tokens)
| RawOperation::Equal(tokens) => tokens,
}
}
pub fn original_text_length(&self) -> usize {
self.tokens().iter().map(Token::get_original_length).sum()
}
pub fn get_original_text(&self) -> String {
self.tokens().iter().map(Token::original).collect()
}
pub fn is_left_joinable(&self) -> bool {
let first_token = self.tokens().first();
first_token.is_none_or(|token| token.is_left_joinable)
}
pub fn is_right_joinable(&self) -> bool {
let last_token = self.tokens().last();
last_token.is_none_or(|token| token.is_right_joinable)
}
/// Extends the operation with another operation. Only operations of the
/// same type as self can be used to extend self, otherwise the function
/// will panic.
pub fn join(self, other: RawOperation<T>) -> RawOperation<T> {
debug_assert!(
std::mem::discriminant(&self) == std::mem::discriminant(&other),
"Cannot extend operations of different types. This should have been handled before \
calling this function."
);
match (self, other) {
(RawOperation::Insert(self_tokens), RawOperation::Insert(other_tokens)) => {
RawOperation::Insert(self_tokens.into_iter().chain(other_tokens).collect())
}
(RawOperation::Delete(tokens1), RawOperation::Delete(tokens2)) => {
RawOperation::Delete(tokens1.into_iter().chain(tokens2).collect())
}
(RawOperation::Equal(tokens1), RawOperation::Equal(tokens2)) => {
RawOperation::Equal(tokens1.into_iter().chain(tokens2).collect())
}
_ => unreachable!("Only operations of the same type can be extended"),
}
}
}