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-rw-r--r--crates/hir_ty/src/diagnostics/decl_check/case_conv.rs249
1 files changed, 123 insertions, 126 deletions
diff --git a/crates/hir_ty/src/diagnostics/decl_check/case_conv.rs b/crates/hir_ty/src/diagnostics/decl_check/case_conv.rs
index 324d60765..b0144a289 100644
--- a/crates/hir_ty/src/diagnostics/decl_check/case_conv.rs
+++ b/crates/hir_ty/src/diagnostics/decl_check/case_conv.rs
@@ -1,156 +1,145 @@
1//! Functions for string case manipulation, such as detecting the identifier case, 1//! Functions for string case manipulation, such as detecting the identifier case,
2//! and converting it into appropriate form. 2//! and converting it into appropriate form.
3 3
4#[derive(Debug)] 4// Code that was taken from rustc was taken at commit 89fdb30,
5enum DetectedCase { 5// from file /compiler/rustc_lint/src/nonstandard_style.rs
6 LowerCamelCase,
7 UpperCamelCase,
8 LowerSnakeCase,
9 UpperSnakeCase,
10 Unknown,
11}
12
13fn detect_case(ident: &str) -> DetectedCase {
14 let trimmed_ident = ident.trim_matches('_');
15 let first_lowercase = trimmed_ident.starts_with(|chr: char| chr.is_ascii_lowercase());
16 let mut has_lowercase = first_lowercase;
17 let mut has_uppercase = false;
18 let mut has_underscore = false;
19
20 for chr in trimmed_ident.chars() {
21 if chr == '_' {
22 has_underscore = true;
23 } else if chr.is_ascii_uppercase() {
24 has_uppercase = true;
25 } else if chr.is_ascii_lowercase() {
26 has_lowercase = true;
27 }
28 }
29
30 if has_uppercase {
31 if !has_lowercase {
32 if has_underscore {
33 DetectedCase::UpperSnakeCase
34 } else {
35 // It has uppercase only and no underscores. Ex: "AABB"
36 // This is a camel cased acronym.
37 DetectedCase::UpperCamelCase
38 }
39 } else if !has_underscore {
40 if first_lowercase {
41 DetectedCase::LowerCamelCase
42 } else {
43 DetectedCase::UpperCamelCase
44 }
45 } else {
46 // It has uppercase, it has lowercase, it has underscore.
47 // No assumptions here
48 DetectedCase::Unknown
49 }
50 } else {
51 DetectedCase::LowerSnakeCase
52 }
53}
54 6
55/// Converts an identifier to an UpperCamelCase form. 7/// Converts an identifier to an UpperCamelCase form.
56/// Returns `None` if the string is already is UpperCamelCase. 8/// Returns `None` if the string is already is UpperCamelCase.
57pub fn to_camel_case(ident: &str) -> Option<String> { 9pub fn to_camel_case(ident: &str) -> Option<String> {
58 let detected_case = detect_case(ident); 10 if is_camel_case(ident) {
59 11 return None;
60 match detected_case {
61 DetectedCase::UpperCamelCase => return None,
62 DetectedCase::LowerCamelCase => {
63 let mut first_capitalized = false;
64 let output = ident
65 .chars()
66 .map(|chr| {
67 if !first_capitalized && chr.is_ascii_lowercase() {
68 first_capitalized = true;
69 chr.to_ascii_uppercase()
70 } else {
71 chr
72 }
73 })
74 .collect();
75 return Some(output);
76 }
77 _ => {}
78 } 12 }
79 13
80 let mut output = String::with_capacity(ident.len()); 14 // Taken from rustc.
81 15 let ret = ident
82 let mut capital_added = false; 16 .trim_matches('_')
83 for chr in ident.chars() { 17 .split('_')
84 if chr.is_alphabetic() { 18 .filter(|component| !component.is_empty())
85 if !capital_added { 19 .map(|component| {
86 output.push(chr.to_ascii_uppercase()); 20 let mut camel_cased_component = String::new();
87 capital_added = true; 21
88 } else { 22 let mut new_word = true;
89 output.push(chr.to_ascii_lowercase()); 23 let mut prev_is_lower_case = true;
24
25 for c in component.chars() {
26 // Preserve the case if an uppercase letter follows a lowercase letter, so that
27 // `camelCase` is converted to `CamelCase`.
28 if prev_is_lower_case && c.is_uppercase() {
29 new_word = true;
30 }
31
32 if new_word {
33 camel_cased_component.push_str(&c.to_uppercase().to_string());
34 } else {
35 camel_cased_component.push_str(&c.to_lowercase().to_string());
36 }
37
38 prev_is_lower_case = c.is_lowercase();
39 new_word = false;
90 } 40 }
91 } else if chr == '_' {
92 // Skip this character and make the next one capital.
93 capital_added = false;
94 } else {
95 // Put the characted as-is.
96 output.push(chr);
97 }
98 }
99 41
100 if output == ident { 42 camel_cased_component
101 // While we didn't detect the correct case at the beginning, there 43 })
102 // may be special cases: e.g. `A` is both valid CamelCase and UPPER_SNAKE_CASE. 44 .fold((String::new(), None), |(acc, prev): (String, Option<String>), next| {
103 None 45 // separate two components with an underscore if their boundary cannot
104 } else { 46 // be distinguished using a uppercase/lowercase case distinction
105 Some(output) 47 let join = if let Some(prev) = prev {
106 } 48 let l = prev.chars().last().unwrap();
49 let f = next.chars().next().unwrap();
50 !char_has_case(l) && !char_has_case(f)
51 } else {
52 false
53 };
54 (acc + if join { "_" } else { "" } + &next, Some(next))
55 })
56 .0;
57 Some(ret)
107} 58}
108 59
109/// Converts an identifier to a lower_snake_case form. 60/// Converts an identifier to a lower_snake_case form.
110/// Returns `None` if the string is already in lower_snake_case. 61/// Returns `None` if the string is already in lower_snake_case.
111pub fn to_lower_snake_case(ident: &str) -> Option<String> { 62pub fn to_lower_snake_case(ident: &str) -> Option<String> {
112 // First, assume that it's UPPER_SNAKE_CASE. 63 if is_lower_snake_case(ident) {
113 match detect_case(ident) { 64 return None;
114 DetectedCase::LowerSnakeCase => return None, 65 } else if is_upper_snake_case(ident) {
115 DetectedCase::UpperSnakeCase => { 66 return Some(ident.to_lowercase());
116 return Some(ident.chars().map(|chr| chr.to_ascii_lowercase()).collect())
117 }
118 _ => {}
119 } 67 }
120 68
121 // Otherwise, assume that it's CamelCase. 69 Some(stdx::to_lower_snake_case(ident))
122 let lower_snake_case = stdx::to_lower_snake_case(ident);
123
124 if lower_snake_case == ident {
125 // While we didn't detect the correct case at the beginning, there
126 // may be special cases: e.g. `a` is both valid camelCase and snake_case.
127 None
128 } else {
129 Some(lower_snake_case)
130 }
131} 70}
132 71
133/// Converts an identifier to an UPPER_SNAKE_CASE form. 72/// Converts an identifier to an UPPER_SNAKE_CASE form.
134/// Returns `None` if the string is already is UPPER_SNAKE_CASE. 73/// Returns `None` if the string is already is UPPER_SNAKE_CASE.
135pub fn to_upper_snake_case(ident: &str) -> Option<String> { 74pub fn to_upper_snake_case(ident: &str) -> Option<String> {
136 match detect_case(ident) { 75 if is_upper_snake_case(ident) {
137 DetectedCase::UpperSnakeCase => return None, 76 return None;
138 DetectedCase::LowerSnakeCase => { 77 } else if is_lower_snake_case(ident) {
139 return Some(ident.chars().map(|chr| chr.to_ascii_uppercase()).collect()) 78 return Some(ident.to_uppercase());
140 } 79 }
141 _ => {} 80
81 Some(stdx::to_upper_snake_case(ident))
82}
83
84// Taken from rustc.
85// Modified by replacing the use of unstable feature `array_windows`.
86fn is_camel_case(name: &str) -> bool {
87 let name = name.trim_matches('_');
88 if name.is_empty() {
89 return true;
142 } 90 }
143 91
144 // Normalize the string from whatever form it's in currently, and then just make it uppercase. 92 let mut fst = None;
145 let upper_snake_case = stdx::to_upper_snake_case(ident); 93 // start with a non-lowercase letter rather than non-uppercase
94 // ones (some scripts don't have a concept of upper/lowercase)
95 !name.chars().next().unwrap().is_lowercase()
96 && !name.contains("__")
97 && !name.chars().any(|snd| {
98 let ret = match (fst, snd) {
99 (None, _) => false,
100 (Some(fst), snd) => {
101 char_has_case(fst) && snd == '_' || char_has_case(snd) && fst == '_'
102 }
103 };
104 fst = Some(snd);
105
106 ret
107 })
108}
109
110fn is_lower_snake_case(ident: &str) -> bool {
111 is_snake_case(ident, char::is_uppercase)
112}
146 113
147 if upper_snake_case == ident { 114fn is_upper_snake_case(ident: &str) -> bool {
148 // While we didn't detect the correct case at the beginning, there 115 is_snake_case(ident, char::is_lowercase)
149 // may be special cases: e.g. `A` is both valid CamelCase and UPPER_SNAKE_CASE. 116}
150 None 117
151 } else { 118// Taken from rustc.
152 Some(upper_snake_case) 119// Modified to allow checking for both upper and lower snake case.
120fn is_snake_case<F: Fn(char) -> bool>(ident: &str, wrong_case: F) -> bool {
121 if ident.is_empty() {
122 return true;
153 } 123 }
124 let ident = ident.trim_matches('_');
125
126 let mut allow_underscore = true;
127 ident.chars().all(|c| {
128 allow_underscore = match c {
129 '_' if !allow_underscore => return false,
130 '_' => false,
131 // It would be more obvious to check for the correct case,
132 // but some characters do not have a case.
133 c if !wrong_case(c) => true,
134 _ => return false,
135 };
136 true
137 })
138}
139
140// Taken from rustc.
141fn char_has_case(c: char) -> bool {
142 c.is_lowercase() || c.is_uppercase()
154} 143}
155 144
156#[cfg(test)] 145#[cfg(test)]
@@ -173,6 +162,7 @@ mod tests {
173 check(to_lower_snake_case, "CamelCase", expect![["camel_case"]]); 162 check(to_lower_snake_case, "CamelCase", expect![["camel_case"]]);
174 check(to_lower_snake_case, "lowerCamelCase", expect![["lower_camel_case"]]); 163 check(to_lower_snake_case, "lowerCamelCase", expect![["lower_camel_case"]]);
175 check(to_lower_snake_case, "a", expect![[""]]); 164 check(to_lower_snake_case, "a", expect![[""]]);
165 check(to_lower_snake_case, "abc", expect![[""]]);
176 } 166 }
177 167
178 #[test] 168 #[test]
@@ -187,6 +177,11 @@ mod tests {
187 check(to_camel_case, "name", expect![["Name"]]); 177 check(to_camel_case, "name", expect![["Name"]]);
188 check(to_camel_case, "A", expect![[""]]); 178 check(to_camel_case, "A", expect![[""]]);
189 check(to_camel_case, "AABB", expect![[""]]); 179 check(to_camel_case, "AABB", expect![[""]]);
180 // Taken from rustc: /compiler/rustc_lint/src/nonstandard_style/tests.rs
181 check(to_camel_case, "X86_64", expect![[""]]);
182 check(to_camel_case, "x86__64", expect![["X86_64"]]);
183 check(to_camel_case, "Abc_123", expect![["Abc123"]]);
184 check(to_camel_case, "A1_b2_c3", expect![["A1B2C3"]]);
190 } 185 }
191 186
192 #[test] 187 #[test]
@@ -197,5 +192,7 @@ mod tests {
197 check(to_upper_snake_case, "CamelCase", expect![["CAMEL_CASE"]]); 192 check(to_upper_snake_case, "CamelCase", expect![["CAMEL_CASE"]]);
198 check(to_upper_snake_case, "lowerCamelCase", expect![["LOWER_CAMEL_CASE"]]); 193 check(to_upper_snake_case, "lowerCamelCase", expect![["LOWER_CAMEL_CASE"]]);
199 check(to_upper_snake_case, "A", expect![[""]]); 194 check(to_upper_snake_case, "A", expect![[""]]);
195 check(to_upper_snake_case, "ABC", expect![[""]]);
196 check(to_upper_snake_case, "X86_64", expect![[""]]);
200 } 197 }
201} 198}