improvement on parsing accuracy for case patterns

src/expand.rs

@@ -500,6 +500,7 @@ pub fn expand_var(chars: &mut Peekable<Chars<'_>>) -> ShResult<String> {
   let mut idx_brace_depth: i32 = 0;
   let mut idx_raw = String::new();
   let mut idx = None;
+  let mut in_operator = false;
   while let Some(&ch) = chars.peek() {
     match ch {
       markers::SUBSH if var_name.is_empty() => {
@@ -555,7 +556,7 @@ pub fn expand_var(chars: &mut Peekable<Chars<'_>>) -> ShResult<String> {
         };
         return Ok(val);
       }
-      '[' if brace_depth > 0 && bracket_depth == 0 && inner_brace_depth == 0 => {
+      '[' if brace_depth > 0 && bracket_depth == 0 && inner_brace_depth == 0 && !in_operator => {
         chars.next(); // consume the bracket
         bracket_depth += 1;
       }
@@ -590,6 +591,9 @@ pub fn expand_var(chars: &mut Peekable<Chars<'_>>) -> ShResult<String> {
         if ch == '}' {
           inner_brace_depth -= 1;
         }
+        if !in_operator && matches!(ch, '#' | '%' | ':' | '/' | '-' | '+' | '=' | '?' | '!') {
+          in_operator = true;
+        }
         var_name.push(ch);
       }
       ch if var_name.is_empty() && PARAMETERS.contains(&ch) => {

src/parse/lex.rs

@@ -1087,11 +1087,26 @@ pub fn case_pat_lookahead(mut chars: Peekable<Chars>) -> Option<usize> {
   while let Some(ch) = chars.next() {
     pos += ch.len_utf8();
     match ch {
-      _ if is_hard_sep(ch) => return None,
+      _ if qt_state.outside() && is_hard_sep(ch) => return None,
       '\\' => {
         if let Some(esc) = chars.next() {
           pos += esc.len_utf8();
         }
+      }
+      '$' if qt_state.outside() && chars.peek() == Some(&'\'') => {
+        // $'...' ANSI-C quoting — skip through to closing quote
+        chars.next(); // consume opening '
+        pos += 1;
+        while let Some(c) = chars.next() {
+          pos += c.len_utf8();
+          if c == '\\' {
+            if let Some(esc) = chars.next() {
+              pos += esc.len_utf8();
+            }
+          } else if c == '\'' {
+            break;
+          }
+        }
       }
 			'\'' => {
 				qt_state.toggle_single();