use std::{borrow::Cow, cmp::max};
use crate::{
abbrev::{ABBREVS, char_is_valid_in_abbrev_tgt},
suffix::SUFFIXES,
};
#[must_use]
pub fn dec_with_default_rules(s: &str) -> String {
dec(ABBREVS, s)
}
#[must_use]
fn do_dec(abbrevs: &[(Cow<'_, str>, Cow<'_, str>, u64)], s: &str) -> String {
let mut result = Vec::with_capacity(s.len());
let mut p = s.as_bytes();
'expanded: while !p.is_empty() {
for chunk in ["Iraq", "e.g.", "i.e.", "(a)", "(b)", "(c)", "(d)", "(e)"] {
if p.starts_with(chunk.as_bytes()) {
p = &p[chunk.len()..];
result.extend(chunk.as_bytes());
continue 'expanded;
}
}
let first_punct = p
.iter()
.copied()
.position(|b| !char_is_valid_in_abbrev_tgt(b));
let idx = max(1, first_punct.unwrap_or(p.len()));
let (mut chunk, rest) = p.split_at(idx);
debug_assert!(!chunk.is_empty());
p = rest;
let ends_in_comma = chunk.ends_with(b",");
if ends_in_comma {
chunk = &chunk[0..chunk.len() - 1];
}
for (long, short, _) in abbrevs {
let s = short.as_bytes();
if chunk == s {
result.extend(long.as_bytes());
if ends_in_comma {
result.push(b',');
}
continue 'expanded;
}
}
if chunk.iter().all(u8::is_ascii_uppercase) {
result.extend(chunk);
if ends_in_comma {
result.push(b',');
}
continue;
}
for (long, short) in SUFFIXES {
if let Some(pre) = chunk.strip_suffix(short.as_bytes()) {
result.extend(pre);
result.extend(long.as_bytes());
if ends_in_comma {
result.push(b',');
}
continue 'expanded;
}
}
result.extend(chunk);
if ends_in_comma {
result.push(b',');
}
}
String::from_utf8(result).unwrap()
}
#[allow(clippy::missing_panics_doc)] #[must_use]
pub fn dec(abbrevs: &[(&str, &str, u64)], s: &str) -> String {
let abbrevs = crate::enc::add_caps(abbrevs);
do_dec(abbrevs.as_slice(), s)
}
#[cfg(test)]
mod test {
use expect_test::expect;
use crate::{
abbrev::{ABBREVS, SUPER_COMMON},
enc::enc_with_default_rules,
};
use super::dec_with_default_rules;
fn d(s: &str) -> String {
dec_with_default_rules(s)
}
#[test]
fn dec_abbrevs() {
for (long, short, _savings) in ABBREVS.iter().copied() {
assert_eq!(d(short), long);
}
}
#[test]
fn dec_aint() {
assert_eq!(d("ai'"), "ain't");
}
#[test]
fn dec_eg() {
assert_eq!(d("e.g."), "e.g.");
}
#[test]
fn dec_iraq() {
assert_eq!(d("Iraq"), "Iraq");
}
#[test]
fn dec_ty() {
assert_eq!(d(",ty"), "thank you");
}
#[test]
fn test_license() {
let expected = expect![[r#"
MIT License
Copyright (c) 2025 Brian Langston Barrett
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE."#]];
expected.assert_eq(&d(include_str!("../../../LICENSE")));
}
#[test]
fn test_readme() {
let expected = expect![[r##"
# Lesshand
Lesshand is a shorthand for the 21st century. You can speed up your writing and
typing by about 5% by learning just 10 of its abbreviations.[^speed]
Unlike other shorthand systems, Lesshand is *lossless*. This means that you can
type quickly in Lesshand and have a computer program *decode* your shorthand
to standard written English. This makes Lesshand suitable for composing emails,
documents, messages, and more.
It's easy to learn Lesshand. In fact, you already know a lot of it! Lesshand
uses familiar abbreviations like "you" for "you", "very" for "very", and "because" for
"because". All of its abbreviations are designed to be mnemonic. It's also
completely incremental; you can learn just a few abbreviations and start
applying them right away.
Check out the [tour] for a quick overview of Lesshand. For more information, see
the [documentation].
[documentation]: https://langston-barrett.github.into/lesshand
[tour]: https://langston-barrett.github.into/lesshand/tour
Lesshand stands for lossLESness shortHANted.
[^speed]: See the documentation for the details of how this claim is evaluated.
"##]];
expected.assert_eq(&d(include_str!("../../../README.md")));
}
fn r(s: &str) -> String {
dec_with_default_rules(&enc_with_default_rules(s))
}
#[test]
fn roundtrip_abbrevs() {
for (long, short, savings) in ABBREVS.iter().copied() {
if savings < 5 && !SUPER_COMMON.contains(&short) {
continue;
}
assert_eq!(r(long), long);
}
}
#[test]
fn roundtrip_abbrev_comma() {
assert_eq!(r("copy,"), "copy,");
}
#[test]
fn roundtrip_suffix_comma() {
assert_eq!(r("information,"), "information,");
}
}