Summary
The initial real-code survey found a frontend gap around reverse-subscript patterns used inside parameter expansion.
Observed example
zsh-plugins/zsh-fancy-completions/lib/completion.zsh
${${${_comps[(I)-value-*]#*,}%%,*}:#-*-}
Official docs context
The Zsh manual documents subscript flags such as i / I and explains that reverse subscripting interprets the completed subscript expression as a pattern. The failure reproduces at the smaller form ${_comps[(I)-value-*]}, so the relevant gap is reverse-subscript pattern parsing rather than nested parameter expansion itself.
Suggested project triage
- Type: Parser gap
- Priority: High
- Effort: Medium
- Status: Ready
Acceptance criteria
- A minimized reverse-subscript-pattern fixture is added.
- The issue links the observed production form to the documented subscript grammar.
- The case remains distinct from generic nested expansion and from filename-generation syntax.
Summary
The initial real-code survey found a frontend gap around reverse-subscript patterns used inside parameter expansion.
Observed example
zsh-plugins/zsh-fancy-completions/lib/completion.zsh${${${_comps[(I)-value-*]#*,}%%,*}:#-*-}Official docs context
The Zsh manual documents subscript flags such as
i/Iand explains that reverse subscripting interprets the completed subscript expression as a pattern. The failure reproduces at the smaller form${_comps[(I)-value-*]}, so the relevant gap is reverse-subscript pattern parsing rather than nested parameter expansion itself.Suggested project triage
Acceptance criteria