typos/src/dict.rs
2019-07-27 19:50:36 -06:00

106 lines
2.9 KiB
Rust

use std::borrow::Cow;
use unicase::UniCase;
use crate::tokens::Case;
pub trait Dictionary {
fn correct_ident<'s, 'w>(
&'s self,
_ident: crate::tokens::Identifier<'w>,
) -> Option<Cow<'s, str>>;
fn correct_word<'s, 'w>(&'s self, word: crate::tokens::Word<'w>) -> Option<Cow<'s, str>>;
}
#[derive(Default)]
pub struct BuiltIn {}
impl BuiltIn {
pub fn new() -> Self {
Self {}
}
pub fn correct_ident<'s, 'w>(
&'s self,
_ident: crate::tokens::Identifier<'w>,
) -> Option<Cow<'s, str>> {
None
}
pub fn correct_word<'s, 'w>(&'s self, word: crate::tokens::Word<'w>) -> Option<Cow<'s, str>> {
map_lookup(&crate::dict_codegen::WORD_DICTIONARY, word.token())
.map(|s| case_correct(s, word.case()))
}
}
impl Dictionary for BuiltIn {
fn correct_ident<'s, 'w>(
&'s self,
ident: crate::tokens::Identifier<'w>,
) -> Option<Cow<'s, str>> {
BuiltIn::correct_ident(self, ident)
}
fn correct_word<'s, 'w>(&'s self, word: crate::tokens::Word<'w>) -> Option<Cow<'s, str>> {
BuiltIn::correct_word(self, word)
}
}
fn map_lookup(
map: &'static phf::Map<UniCase<&'static str>, &'static str>,
key: &str,
) -> Option<&'static str> {
// This transmute should be safe as `get` will not store the reference with
// the expanded lifetime. This is due to `Borrow` being overly strict and
// can't have an impl for `&'static str` to `Borrow<&'a str>`.
//
//
// See https://github.com/rust-lang/rust/issues/28853#issuecomment-158735548
unsafe {
let key = ::std::mem::transmute::<_, &'static str>(key);
map.get(&UniCase(key)).cloned()
}
}
fn case_correct(correction: &str, case: Case) -> Cow<'_, str> {
match case {
Case::Lower | Case::None => correction.into(),
Case::Title => {
let mut title = String::with_capacity(correction.as_bytes().len());
let mut char_indices = correction.char_indices();
if let Some((_, c)) = char_indices.next() {
title.extend(c.to_uppercase());
if let Some((i, _)) = char_indices.next() {
title.push_str(&correction[i..]);
}
}
title.into()
}
Case::Scream => correction
.chars()
.flat_map(|c| c.to_uppercase())
.collect::<String>()
.into(),
}
}
#[cfg(test)]
mod test {
use super::*;
#[test]
fn test_case_correct() {
let cases = [
("foo", Case::Lower, "foo"),
("foo", Case::None, "foo"),
("foo", Case::Title, "Foo"),
("foo", Case::Scream, "FOO"),
("fOo", Case::None, "fOo"),
];
for (correction, case, expected) in cases.iter() {
let actual = case_correct(correction, *case);
assert_eq!(*expected, actual);
}
}
}