1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
|
pub fn to_camel_case(ident: &str) -> Option<String> {
let mut output = String::new();
if is_camel_case(ident) {
return None;
}
let mut capital_added = false;
for chr in ident.chars() {
if chr.is_alphabetic() {
if !capital_added {
output.push(chr.to_ascii_uppercase());
capital_added = true;
} else {
output.push(chr.to_ascii_lowercase());
}
} else if chr == '_' {
// Skip this character and make the next one capital.
capital_added = false;
} else {
// Put the characted as-is.
output.push(chr);
}
}
if output == ident {
None
} else {
Some(output)
}
}
pub fn to_lower_snake_case(ident: &str) -> Option<String> {
// First, assume that it's UPPER_SNAKE_CASE.
if let Some(normalized) = to_lower_snake_case_from_upper_snake_case(ident) {
return Some(normalized);
}
// Otherwise, assume that it's CamelCase.
let lower_snake_case = stdx::to_lower_snake_case(ident);
if lower_snake_case == ident {
None
} else {
Some(lower_snake_case)
}
}
fn to_lower_snake_case_from_upper_snake_case(ident: &str) -> Option<String> {
if is_upper_snake_case(ident) {
let string = ident.chars().map(|c| c.to_ascii_lowercase()).collect();
Some(string)
} else {
None
}
}
fn is_upper_snake_case(ident: &str) -> bool {
ident.chars().all(|c| c.is_ascii_uppercase() || c == '_')
}
fn is_camel_case(ident: &str) -> bool {
// We assume that the string is either snake case or camel case.
ident.chars().all(|c| c != '_')
}
#[cfg(test)]
mod tests {
use super::*;
use expect_test::{expect, Expect};
fn check<F: Fn(&str) -> Option<String>>(fun: F, input: &str, expect: Expect) {
// `None` is translated to empty string, meaning that there is nothing to fix.
let output = fun(input).unwrap_or_default();
expect.assert_eq(&output);
}
#[test]
fn test_to_lower_snake_case() {
check(to_lower_snake_case, "lower_snake_case", expect![[""]]);
check(to_lower_snake_case, "UPPER_SNAKE_CASE", expect![["upper_snake_case"]]);
check(to_lower_snake_case, "CamelCase", expect![["camel_case"]]);
}
#[test]
fn test_to_camel_case() {
check(to_camel_case, "CamelCase", expect![[""]]);
check(to_camel_case, "lower_snake_case", expect![["LowerSnakeCase"]]);
check(to_camel_case, "UPPER_SNAKE_CASE", expect![["UpperSnakeCase"]]);
}
}
|
