diff options
Diffstat (limited to 'docs')
| -rw-r--r-- | docs/fs.md | 20 |
1 files changed, 14 insertions, 6 deletions
@@ -151,9 +151,9 @@ and `not a session control message "X"` or `not a window control message "X"` for a word of the other ctl. 9ns maps them all to EINVAL, and a write refused here has done nothing. A line that then fails as it runs fails the write with the error the editor reports for it and the line, e.g. `Mount: -AlreadyMounted "Mount peer /tmp/s"` (EIO); so does `control message needs -its argument "Save"`, for a builtin that would have asked at a prompt (a -`Save` on a scratch) rather than open one nobody is there to answer. The +AlreadyMounted "Mount peer /tmp/s"` (EIO), and `control message needs its +argument "Save"` (EINVAL), for a builtin that would have asked at a prompt +(a `Save` on a scratch) rather than open one nobody is there to answer. The lines before a failing one have taken effect and those after it never run, which is what acme's ctl loop does (editors/acme/xfid.c:600-790). An error that only happens as the editor performs what a line asked for -- a `Save` @@ -314,7 +314,8 @@ pattern that spans lines, `^`, `$` and `[^...]` keep mvzr's own meaning. mvzr backtracks without bound of its own (`a?` twenty times then twenty `a`s is 2^20 steps from each place it tries), and a search holds the editor, so pardes patches a step budget into mvzr's matcher (build.zig): a search that spends it, -about 300 ms, fails with `regular expression search took too long` rather +about 300 ms, fails with `regular expression search gave up, backtracking +past its step budget` rather than answer a match it is not sure of. Ordinary patterns spend a few thousand steps; what runs out is exponential backtracking, and a quadratic pattern over a very long line (`\s*(\w+)\s*=` over 20 KB of letters). @@ -324,7 +325,7 @@ is the one place both call), so `^` there also means a line's start. An address that does not evaluate fails the write with why: `bad address syntax`, `no match for regexp`, `address out of range`, `bad regular -expression`, `regular expression search took too long`, or sam's +expression`, `regular expression search gave up, ...`, or sam's `addresses out of order` for a range that ends before it starts (`#100,#50`), which acme lets through. A failed write to `addr` leaves no address at all, where acme @@ -370,7 +371,14 @@ reply to, usually `Invalid argument`, and this is the reason (`err 3 addr: no match for regexp`). The same err again, before any follower has read the first, is that record counted (`err 3 addr: no match for regexp (x4)`), so a client retrying a failing write does not push the rest out of the -ring; a follower that read it gets each repeat. There is no per-pane error file to read instead: +ring; a follower that read it gets each repeat. Through a kernel mount a client sees only an errno, which 9ns reads from the +error's words (cloud9's 9ns/src/nine.zig, `enameToErrno`): a malformed write +-- an unknown or ill-formed control message, `bad address syntax`, `bad +regular expression` -- is EINVAL; a lock another open holds, EBUSY; a pane +gone, ENOENT; a well-formed write that fails -- `no match for regexp`, +`address out of range`, `addresses out of order`, a search that gave up, +`<name>: Modified (Exit again to discard)` -- EIO. The err record has the +words. There is no per-pane error file to read instead: acme's `errors` only takes text, and one record stream is simpler to watch than a file per pane. A `msg` said while a pane is being made can precede that pane's `new`; panes present at boot are |