fileset: parse glob characters as identifier

It's inconvenient that we have to quote glob patterns as 'glob:"*.rs"'. Suppose
filesets are usually specified in shell, it's better to allow unquoted strings
if possible. This change also means we'll probably abandon #2101 "make the
parsing of string arguments stricter."

Note that we can no longer introduce ? operator or [] subscript syntax in
filesets.

Closes #4053

cli/tests/test_diff_command.rs

@@ -204,7 +204,7 @@ fn test_diff_basic() {
             "diff",
             "--config-toml=ui.allow-filesets=true",
             "-s",
-            r#"glob:"file[12]""#,
+            "glob:file[12]",
         ],
     );
     insta::assert_snapshot!(stdout, @r###"

docs/filesets.md

@@ -21,6 +21,11 @@ if the expression has no operators nor function calls. For example:
 * `jj diff '~"Foo Bar"'` (both shell and inner quotes are required)
 * `jj diff '"Foo(1)"'` (both shell and inner quotes are required)
 
+Glob characters aren't considered meta characters, but shell quotes are still
+required:
+
+* `jj diff '~glob:**/*.rs'`
+
 [string-literals]: templates.md#string-literals
 
 ## File patterns

lib/src/fileset.pest

@@ -16,22 +16,21 @@ whitespace = _{ " " | "\t" | "\r" | "\n" | "\x0c" }
 
 // XID_CONTINUE: https://www.unicode.org/reports/tr31/#Default_Identifier_Syntax
 // +, -, ., @, _: commonly used in file name including "." and ".."
+// *, ?, [, ]: glob characters (not extended glob)
 // /: path separator
 // \: path separator (Windows)
-// TODO: accept glob characters as identifier?
 identifier = @{
-  (XID_CONTINUE | "+" | "-" | "." | "@" | "_" | "/" | "\\")+
+  (XID_CONTINUE | "+" | "-" | "." | "@" | "_" | "*" | "?" | "[" | "]" | "/" | "\\")+
 }
 strict_identifier_part = @{ (ASCII_ALPHANUMERIC | "_")+ }
 strict_identifier = @{
   strict_identifier_part ~ ("-" ~ strict_identifier_part)*
 }
 
-// TODO: accept glob characters?
 // TODO: accept more ASCII meta characters such as "#" and ","?
 bare_string = @{
   ( ASCII_ALPHANUMERIC
-  | " " | "+" | "-" | "." | "@" | "_" | "/" | "\\"
+  | " " | "+" | "-" | "." | "@" | "_" | "*" | "?" | "[" | "]" | "/" | "\\"
   | '\u{80}'..'\u{10ffff}' )+
 }
 

lib/src/fileset_parser.rs

@@ -458,6 +458,10 @@ mod tests {
             parse_into_kind(r#"Windows\Path"#),
             Ok(ExpressionKind::Identifier(r#"Windows\Path"#))
         );
+        assert_eq!(
+            parse_into_kind("glob*[chars]?"),
+            Ok(ExpressionKind::Identifier("glob*[chars]?"))
+        );
     }
 
     #[test]
@@ -502,6 +506,13 @@ mod tests {
                 value: "bar".to_owned()
             })
         );
+        assert_eq!(
+            parse_into_kind(" foo:glob*[chars]? "),
+            Ok(ExpressionKind::StringPattern {
+                kind: "foo",
+                value: "glob*[chars]?".to_owned()
+            })
+        );
         assert_eq!(
             parse_into_kind(r#" foo:"bar" "#),
             Ok(ExpressionKind::StringPattern {
@@ -645,6 +656,13 @@ mod tests {
                 value: " bar baz".to_owned()
             })
         );
+        assert_eq!(
+            parse_maybe_bare_into_kind("foo:glob * [chars]?"),
+            Ok(ExpressionKind::StringPattern {
+                kind: "foo",
+                value: "glob * [chars]?".to_owned()
+            })
+        );
         assert_eq!(
             parse_maybe_bare_into_kind("foo:bar:baz"),
             Err(FilesetParseErrorKind::SyntaxError)