expr: Refactor caret options into one pattern

Author: frendsick

src/uu/expr/src/syntax_tree.rs

@@ -173,13 +173,13 @@ impl StringOp {
                     match curr {
                         '^' => match (prev, prev_is_escaped) {
                             // Start of a capturing group
-                            ('(', true) => re_string.push(curr),
+                            ('(', true)
                             // Start of an alternative pattern
-                            ('|', true) => re_string.push(curr),
+                            | ('|', true)
                             // Character class negation "[^a]"
-                            ('[', false) => re_string.push(curr),
+                            | ('[', false)
                             // Explicitly escaped caret
-                            ('\\', false) => re_string.push(curr),
+                            | ('\\', false) => re_string.push(curr),
                             _ => re_string.push_str(r"\^"),
                         },
                         '$' => {