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pub trait JoinWithString<S> {
fn join(self, separator: S) -> String;
}
impl<S, S2, X> JoinWithString<S2> for X
where S: AsRef<str>,
S2: AsRef<str>,
X: Iterator<Item = S>
{
fn join(self, separator: S2) -> String {
self.fold("".to_string(), |a, b| {
let m = if a.is_empty() {
a
} else {
a + separator.as_ref()
};
m + b.as_ref()
})
}
}
#[derive(PartialEq, Debug)]
enum WordCase {
Upper,
Lower,
Capitalized,
}
pub struct WordIterator<'a> {
string: &'a str,
index: usize,
previous_word_case: Option<WordCase>,
}
impl<'a> WordIterator<'a> {
pub fn new(string: &str) -> WordIterator {
WordIterator {
string: string,
index: 0,
previous_word_case: None,
}
}
}
fn char_at(str: &str, index: usize) -> char {
if index >= str.len() {
panic!("char_at: index out of bounds");
}
str[index..index + 1].chars().next().unwrap()
}
impl<'a> Iterator for WordIterator<'a> {
type Item = &'a str;
fn next(&mut self) -> Option<&'a str> {
while self.index < self.string.len() && &self.string[self.index..self.index + 1] == "_" {
self.index += 1;
}
if self.index >= self.string.len() {
return None;
}
let mut i = self.index;
let mut word_case = WordCase::Lower;
while i < self.string.len() {
let current = char_at(self.string, i);
if current == '_' {
break;
}
if i - self.index == 0 {
if current.is_uppercase() {
word_case = WordCase::Capitalized;
} else {
word_case = WordCase::Lower;
}
} else if i - self.index == 1 {
if current.is_uppercase() {
if word_case == WordCase::Capitalized {
let next_not_upper = if i + 1 < self.string.len() {
!char_at(self.string, i + 1).is_uppercase()
} else {
true
};
if next_not_upper || self.previous_word_case == Some(WordCase::Capitalized) {
break;
} else {
word_case = WordCase::Upper;
}
} else if word_case == WordCase::Lower {
break;
}
}
} else {
match word_case {
WordCase::Lower | WordCase::Capitalized => {
if current.is_uppercase() {
break;
}
}
WordCase::Upper => {
if !current.is_uppercase() {
break;
}
}
}
}
i += 1;
}
let result = &self.string[self.index..i];
self.index = i;
self.previous_word_case = Some(word_case);
Some(result)
}
}
pub trait CaseOperations {
fn to_class_case(&self) -> String;
fn to_snake_case(&self) -> String;
}
pub trait VecCaseOperations {
fn to_class_case(self) -> String;
fn to_snake_case(self) -> String;
}
fn iterator_to_class_case<S: AsRef<str>, T: Iterator<Item = S>>(it: T) -> String {
it.map(|x| {
format!("{}{}",
x.as_ref()[0..1].to_uppercase(),
x.as_ref()[1..].to_lowercase())
})
.join("")
}
fn iterator_to_snake_case<S: AsRef<str>, T: Iterator<Item = S>>(it: T) -> String {
it.map(|x| x.as_ref().to_lowercase()).join("_")
}
#[cfg_attr(feature="clippy", allow(needless_range_loop))]
fn replace_all_sub_vecs(parts: &mut Vec<String>, needle: Vec<&str>) {
let mut any_found = true;
while any_found {
any_found = false;
if parts.len() + 1 >= needle.len() {
for i in 0..parts.len() + 1 - needle.len() {
if &parts[i..i + needle.len()] == &needle[..] {
for _ in 0..needle.len() - 1 {
parts.remove(i + 1);
}
parts[i] = needle.join("");
any_found = true;
break;
}
}
}
}
}
impl CaseOperations for String {
fn to_class_case(&self) -> Self {
iterator_to_class_case(WordIterator::new(self))
}
fn to_snake_case(&self) -> Self {
let mut parts: Vec<_> = WordIterator::new(self).map(|x| x.to_lowercase()).collect();
replace_all_sub_vecs(&mut parts, vec!["na", "n"]);
replace_all_sub_vecs(&mut parts, vec!["open", "g", "l"]);
parts.join("_")
}
}
impl<'a> VecCaseOperations for Vec<&'a str> {
fn to_class_case(self) -> String {
iterator_to_class_case(self.into_iter())
}
fn to_snake_case(self) -> String {
iterator_to_snake_case(self.into_iter())
}
}