Auto merge of #57651 - JohnTitor:give-char-type, r=estebank

Implement new literal type `Err`

Fixes #57384

I removed `return Ok`, otherwise, two errors occur. Any solutions?

r? @estebank

src/test/ui/parser/lex-bad-char-literals-2.rs

@@ -1,4 +1,4 @@
 // This test needs to the last one appearing in this file as it kills the parser
 static c: char =
-    'nope' //~ ERROR: character literal may only contain one codepoint: 'nope'
+    'nope' //~ ERROR: character literal may only contain one codepoint
 ;

src/test/ui/parser/lex-bad-char-literals-2.stderr

@@ -1,8 +1,13 @@
-error: character literal may only contain one codepoint: 'nope'
+error: character literal may only contain one codepoint
   --> $DIR/lex-bad-char-literals-2.rs:3:5
    |
-LL |     'nope' //~ ERROR: character literal may only contain one codepoint: 'nope'
+LL |     'nope' //~ ERROR: character literal may only contain one codepoint
    |     ^^^^^^
 
-error: aborting due to previous error
+error[E0601]: `main` function not found in crate `lex_bad_char_literals_2`
+   |
+   = note: consider adding a `main` function to `$DIR/lex-bad-char-literals-2.rs`
 
+error: aborting due to 2 previous errors
+
+For more information about this error, try `rustc --explain E0601`.

src/test/ui/parser/lex-bad-char-literals-3.rs

@@ -1,7 +1,7 @@
-// This test needs to the last one appearing in this file as it kills the parser
-static c: char =
-    '●●' //~ ERROR: character literal may only contain one codepoint
-         //~| ERROR: mismatched types
-;
+static c: char = '●●';
+//~^ ERROR: character literal may only contain one codepoint
 
-fn main() {}
+fn main() {
+    let ch: &str = '●●';
+    //~^ ERROR: character literal may only contain one codepoint
+}

src/test/ui/parser/lex-bad-char-literals-3.stderr

@@ -1,22 +1,22 @@
 error: character literal may only contain one codepoint
-  --> $DIR/lex-bad-char-literals-3.rs:3:5
+  --> $DIR/lex-bad-char-literals-3.rs:1:18
    |
-LL |     '●●' //~ ERROR: character literal may only contain one codepoint
-   |     ^^^^
+LL | static c: char = '●●';
+   |                  ^^^^
 help: if you meant to write a `str` literal, use double quotes
    |
-LL |     "●●" //~ ERROR: character literal may only contain one codepoint
-   |     ^^^^
+LL | static c: char = "●●";
+   |                  ^^^^
 
-error[E0308]: mismatched types
-  --> $DIR/lex-bad-char-literals-3.rs:3:5
+error: character literal may only contain one codepoint
+  --> $DIR/lex-bad-char-literals-3.rs:5:20
    |
-LL |     '●●' //~ ERROR: character literal may only contain one codepoint
-   |     ^^^^ expected char, found reference
+LL |     let ch: &str = '●●';
+   |                    ^^^^
+help: if you meant to write a `str` literal, use double quotes
    |
-   = note: expected type `char`
-              found type `&'static str`
+LL |     let ch: &str = "●●";
+   |                    ^^^^
 
 error: aborting due to 2 previous errors
 
-For more information about this error, try `rustc --explain E0308`.

src/test/ui/parser/lex-bad-char-literals-4.rs

@@ -1,5 +1,5 @@
 //
 // This test needs to the last one appearing in this file as it kills the parser
 static c: char =
-    '●  //~ ERROR: character literal may only contain one codepoint: '●
+    '●  //~ ERROR: character literal may only contain one codepoint
 ;

src/test/ui/parser/lex-bad-char-literals-4.stderr

@@ -1,7 +1,7 @@
 error: character literal may only contain one codepoint: '●
   --> $DIR/lex-bad-char-literals-4.rs:4:5
    |
-LL |     '●  //~ ERROR: character literal may only contain one codepoint: '●
+LL |     '●  //~ ERROR: character literal may only contain one codepoint
    |     ^^
 
 error: aborting due to previous error

src/test/ui/parser/lex-bad-char-literals-5.rs

@@ -1,8 +1,7 @@
-//
-// This test needs to the last one appearing in this file as it kills the parser
-static c: char =
-    '\x10\x10'  //~ ERROR: character literal may only contain one codepoint
-                //~| ERROR: mismatched types
-;
+static c: char = '\x10\x10';
+//~^ ERROR: character literal may only contain one codepoint
 
-fn main() {}
+fn main() {
+    let ch: &str = '\x10\x10';
+    //~^ ERROR: character literal may only contain one codepoint
+}

src/test/ui/parser/lex-bad-char-literals-5.stderr

@@ -1,22 +1,22 @@
 error: character literal may only contain one codepoint
-  --> $DIR/lex-bad-char-literals-5.rs:4:5
+  --> $DIR/lex-bad-char-literals-5.rs:1:18
    |
-LL |     '/x10/x10'  //~ ERROR: character literal may only contain one codepoint
-   |     ^^^^^^^^^^
+LL | static c: char = '/x10/x10';
+   |                  ^^^^^^^^^^
 help: if you meant to write a `str` literal, use double quotes
    |
-LL |     "/x10/x10"  //~ ERROR: character literal may only contain one codepoint
-   |     ^^^^^^^^^^
+LL | static c: char = "/x10/x10";
+   |                  ^^^^^^^^^^
 
-error[E0308]: mismatched types
-  --> $DIR/lex-bad-char-literals-5.rs:4:5
+error: character literal may only contain one codepoint
+  --> $DIR/lex-bad-char-literals-5.rs:5:20
    |
-LL |     '/x10/x10'  //~ ERROR: character literal may only contain one codepoint
-   |     ^^^^^^^^^^ expected char, found reference
+LL |     let ch: &str = '/x10/x10';
+   |                    ^^^^^^^^^^
+help: if you meant to write a `str` literal, use double quotes
    |
-   = note: expected type `char`
-              found type `&'static str`
+LL |     let ch: &str = "/x10/x10";
+   |                    ^^^^^^^^^^
 
 error: aborting due to 2 previous errors
 
-For more information about this error, try `rustc --explain E0308`.

src/test/ui/parser/lex-bad-char-literals-6.rs

@@ -0,0 +1,17 @@
+fn main() {
+    let x: &str = 'ab';
+    //~^ ERROR: character literal may only contain one codepoint
+    let y: char = 'cd';
+    //~^ ERROR: character literal may only contain one codepoint
+    let z = 'ef';
+    //~^ ERROR: character literal may only contain one codepoint
+
+    if x == y {}
+    //~^ ERROR: can't compare `&str` with `char`
+    if y == z {}  // no error here
+    if x == z {}
+    //~^ ERROR: can't compare `&str` with `char`
+
+    let a: usize = "";
+    //~^ ERROR: mismatched types
+}

src/test/ui/parser/lex-bad-char-literals-6.stderr

@@ -0,0 +1,47 @@
+error: character literal may only contain one codepoint
+  --> $DIR/lex-bad-char-literals-6.rs:2:19
+   |
+LL |     let x: &str = 'ab';
+   |                   ^^^^
+
+error: character literal may only contain one codepoint
+  --> $DIR/lex-bad-char-literals-6.rs:4:19
+   |
+LL |     let y: char = 'cd';
+   |                   ^^^^
+
+error: character literal may only contain one codepoint
+  --> $DIR/lex-bad-char-literals-6.rs:6:13
+   |
+LL |     let z = 'ef';
+   |             ^^^^
+
+error[E0277]: can't compare `&str` with `char`
+  --> $DIR/lex-bad-char-literals-6.rs:9:10
+   |
+LL |     if x == y {}
+   |          ^^ no implementation for `&str == char`
+   |
+   = help: the trait `std::cmp::PartialEq<char>` is not implemented for `&str`
+
+error[E0308]: mismatched types
+  --> $DIR/lex-bad-char-literals-6.rs:15:20
+   |
+LL |     let a: usize = "";
+   |                    ^^ expected usize, found reference
+   |
+   = note: expected type `usize`
+              found type `&'static str`
+
+error[E0277]: can't compare `&str` with `char`
+  --> $DIR/lex-bad-char-literals-6.rs:12:10
+   |
+LL |     if x == z {}
+   |          ^^ no implementation for `&str == char`
+   |
+   = help: the trait `std::cmp::PartialEq<char>` is not implemented for `&str`
+
+error: aborting due to 6 previous errors
+
+Some errors occurred: E0277, E0308.
+For more information about an error, try `rustc --explain E0277`.

src/test/ui/str/str-as-char.fixed

@@ -1,6 +1,6 @@
 // run-rustfix
 
 fn main() {
-    println!("●●");
-    //~^ ERROR character literal may only contain one codepoint
+    println!("{}", "●●"); //~ ERROR character literal may only contain one codepoint
+    //~^ ERROR format argument must be a string literal
 }

src/test/ui/str/str-as-char.rs

@@ -1,6 +1,6 @@
 // run-rustfix
 
 fn main() {
-    println!('●●');
-    //~^ ERROR character literal may only contain one codepoint
+    println!('●●'); //~ ERROR character literal may only contain one codepoint
+    //~^ ERROR format argument must be a string literal
 }

src/test/ui/str/str-as-char.stderr

@@ -1,12 +1,22 @@
 error: character literal may only contain one codepoint
   --> $DIR/str-as-char.rs:4:14
    |
-LL |     println!('●●');
+LL |     println!('●●'); //~ ERROR character literal may only contain one codepoint
    |              ^^^^
 help: if you meant to write a `str` literal, use double quotes
    |
-LL |     println!("●●");
+LL |     println!("●●"); //~ ERROR character literal may only contain one codepoint
    |              ^^^^
 
-error: aborting due to previous error
+error: format argument must be a string literal
+  --> $DIR/str-as-char.rs:4:14
+   |
+LL |     println!('●●'); //~ ERROR character literal may only contain one codepoint
+   |              ^^^^
+help: you might be missing a string literal to format with
+   |
+LL |     println!("{}", '●●'); //~ ERROR character literal may only contain one codepoint
+   |              ^^^^^
+
+error: aborting due to 2 previous errors