Dired arc Stage 0 (docs/dired-framing.md section 10, Q#DR11). Until now
pmacs had no discoverable way to open a file by path: no find-file
command and no C-x C-f binding, so a file entered a session only from
the CLI, an LSP jump, a project-search visit, or C-x C-r, whose prompt
does pass free text through but completes only over the recent list.
The command prompts with completion rooted at the active buffer's
directory, or the process cwd when the buffer has no backing path, and
opens the result through pmacs.window.display_file. A path that does not
exist yet creates a buffer bound to it with the "[new file]" status,
which is Emacs parity and comes from resolve_target_buffer rather than
anything added here. Nothing is written to disk until the user saves.
Two substrate facts shape the design and are documented at the command
rather than left to be rediscovered.
Completion is flat: the files source lists one directory and yields bare
basenames, and a custom function source could not do better, because
sources are called with no arguments and run synchronously outside any
coroutine, so a callback can neither see the input to re-root on nor
await a directory listing. Hierarchical completion is a named Rust
change in the framing.
A selected candidate shadows typed text: recompute_candidates selects
index 0 whenever the candidate list is non-empty, and
resolve_accepted_value returns the candidate over the typed contents. So
typed text reaches the accept handler exactly when the input filters
every candidate away, which for basename candidates under a subsequence
filter means when it contains a separator. That makes the deeper-path
case work verbatim and leaves one hole: a new bare name that is a
subsequence of an existing entry opens the existing file. The acceptance
pins that as a decision rather than an accident; closing it needs a Rust
change to accept semantics that Stage 0 deliberately does not make.
A leading tilde is expanded before the path reaches the core, because
get_or_load_buffer normalizes the path it stores but loads from the raw
one -- so an unexpanded tilde path deduplicates against an already-open
buffer yet fails to load a file that is not open yet.
The prompt field starts empty and names its root in the prompt string
instead: any prefill would contain a separator and silently disable
completion.
Acceptance is dispatch-driven throughout -- a real C-x C-f, real typing,
a real RET -- so a dead binding cannot pass vacuously and the Lua
lifecycle accept(), which bypasses the path interactive input takes, is
not used.
Levi Neuwirth
2a0884b377