Three review findings, all in builtin/runtime/syntax.lua.
1. [P1] Syntax bypassed extension precedence and grammar availability.
attach_for_active_buffer resolved `language_for_path or shebang`, but
language_for_path knows only grammar-backed extensions — so a `.py`
file opening with `#!/bin/sh` fell through to the shebang and got a
bash parse tree, and an extensionless `#!/usr/bin/env python3` script
dispatched "python" (no grammar) and raised "unknown language". A new
resolve_active_language walks the full precedence chain — grammar
extension -> LSP filetype map -> shebang — consulting the shebang only
when the extension is unrecognized (a recognized non-grammar extension
like .py is authoritative). Dispatch is then gated on
pmacs.parse._has_language(lang), so grammarless languages are skipped
silently. The extension parts stay keyed on buf:name() (unchanged from
before), so path-less buffers that resolve a grammar by name — e.g.
generated markdown buffers — are unaffected.
2. [P2] Editing an open script's shebang left parsing/highlighting stale.
The after-edit path re-sniffed the mutable shebang: sh -> python
raised "unknown language" while leaving the old bash tree, and
sh -> lua swapped the parse tree under a highlight overlay still
holding the original grammar's query. Reparse now uses the language
pinned at first attach (parse_lang_by_buffer), never re-resolving —
a language change needs a close/reopen, as it does for extensions.
3. [P2] `env` options with operands were mistaken for interpreters.
`#!/usr/bin/env -u FOO python3` skipped `-u` but took `FOO`. The env
walk now skips the operand of the operand-consuming GNU-env options
(-u/--unset, -C/--chdir, -a/--argv0) before selecting the interpreter.
-S/--split-string stays excluded (its string carries the interpreter).
Tests (bite-verified against pre-fix syntax.lua — each fails without its
fix; scripts/bite HEAD builtin/runtime/syntax.lua):
- m4_shebang_does_not_override_extension now also asserts _has_view is
false (no bash grammar tree for a `.py` + `#!/bin/sh`), not only the
LSP language.
- m4_shebang_extensionless_grammarless_language_is_silent — extensionless
python resolves for LSP, gets no grammar view, and records no error.
- m4_shebang_edit_keeps_pinned_grammar — rewriting a `#!/bin/sh` script's
shebang to lua keeps the bash tree and reports no error.
- m4_shebang_resolver_maps_interpreters — added the env-operand cases
(`-u FOO`, `-C /tmp`, combined).
Gates: fmt; clippy -D warnings; m4_acceptance --skip basedpyright; GPU;
git diff --check all green. The only sweep failure is the pre-existing
editor::composition_overhead_under_ten_percent render microbenchmark
(ratio hovers at the 1.10 cutoff; flakes ~1/3 even isolated single-
threaded, already asserted-off on macOS) — a pure-Rust render loop this
Lua-only change cannot touch. Change is Lua-only plus the acceptance
tests.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01YJ9FQ832QwftJXCD9LeFan
Levi Neuwirth
f300b77533