A look with a blank in its pattern addresses, file:N selects the line, and a miss is said, logged and reads back empty

Round 6: look calc.py:/return a/ was a word search, since a blank ended the address; calc.py:99 past the end focused the file and said nothing; and /look still read back the pane before a miss. A pattern after the colon may now hold blanks; file:N selects the line, newline included, as acme's does; a line past the end opens and focuses nothing; and every miss (no match, a bad address, a line past the end) says so, logs err <serial> look: why, keeps the selection, and leaves look reading back empty. Documented, with file:0/re/ for the first match, since acme evaluates the address from the file's dot. Five goldens change: a look at file:N now selects the line.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

1 files changed, 12 insertions, 6 deletions

diff --git a/docs/fs.md b/docs/fs.md
index f6516ea1..a489e1ea 100644
--- a/docs/fs.md
+++ b/docs/fs.md
@@ -309,12 +309,18 @@ not the hits buffer it opened.
 
 A look takes acme's addresses after a colon (editors/acme/look.c:450): a
 line written to `look` as `file:/re/`, `file:#n`, `file:$` or any address
-opens (or finds) the file and selects what the address names, evaluated
-from its dot; `:addr` does the same in the pane itself. `file:12` and
-`file:12:5` stay line and column. A bare `/re/` is a path, as in acme, and
-failing that a search for its text. A look that finds nothing, or an
-address that does not evaluate, says so on the message row and changes
-nothing: no buffer opens and the selection stays.
+opens (or finds) the file and selects what the address names. **The
+address is evaluated from the file's dot**, as acme's is: `file:/re/`
+finds the next match after the current selection, not the first in the
+file. For the first, start at the top: `file:0/re/` (or `file:#0/re/`).
+`:addr` does the same in the pane itself, and a pattern may hold blanks
+(`calc.py:/return a/`). `file:12` selects line 12, its newline included,
+as acme's does; `file:12:5` puts the caret at line 12, column 5. A bare
+`/re/` is a path, as in acme, and failing that a search for its text. A
+look that finds nothing, an address that does not evaluate, or a line past
+the file's end (`calc.py:99`) says so on the message row and in the log
+(`err <serial> look: ...`), focuses and opens nothing, keeps the
+selection, and leaves `look` reading back empty.
 
 `/pane/<n>/name` reads the pane's file name (a terminal's directory) and
 writing it renames the buffer; a relative name resolves against the pane's