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, 15 insertions, 0 deletions

diff --git a/src/ninep/ctl.zig b/src/ninep/ctl.zig
index b11692e0..edf81cd9 100644
--- a/src/ninep/ctl.zig
+++ b/src/ninep/ctl.zig
@@ -69,10 +69,13 @@ fn run(p: *Pardes, id: usize, exec: bool, text: []const u8) void {
     const before = Serials.snapshot(p);
     // An exec answers the pane it went to: a command pane it reused, or
     // the terminal it typed into.
+    p.look_missed = false;
     const went: ?usize = if (exec) pardes.exec.execute(p, id, text) else blk: {
         look.lookAt(p, id, text);
         break :blk null;
     };
+    // A look that found nothing answers nothing, not the pane before it.
+    if (!exec and p.look_missed) return;
     const after = Serials.snapshot(p);
     var created = false;
     for (after.list[0..after.len]) |serial| if (std.mem.indexOfScalar(u32, before.list[0..before.len], serial) == null) {
@@ -892,6 +895,18 @@ test "a look takes acme's :addr and file:addr, and a miss changes nothing" {
     try testing.expectEqual(Status.ok, wr(p, look_node, "foo\n").reply.status);
     var own: [16]u8 = undefined;
     try testing.expectEqualStrings(try std.fmt.bufPrint(&own, "{d}\n", .{serial}), rd(p, look_node, 0, 64).bytes);
+    // A pattern with a blank in it; 0/re/ searches from the top, whatever dot is.
+    try testing.expectEqual(Status.ok, wr(p, look_node, ":/foo y/\n").reply.status);
+    try testing.expectEqualStrings("          6          11 ", rd(p, dot, 0, 64).bytes);
+    try testing.expectEqual(Status.ok, wr(p, look_node, try std.fmt.bufPrint(&line, "{s}:0/foo/\n", .{path})).reply.status);
+    try testing.expectEqualStrings("          0           3 ", rd(p, dot, 0, 64).bytes);
+    // file:N selects the line; a line past the end moves nothing and reads back empty.
+    try testing.expectEqual(Status.ok, wr(p, look_node, try std.fmt.bufPrint(&line, "{s}:2\n", .{path})).reply.status);
+    try testing.expectEqualStrings("         12          16 ", rd(p, dot, 0, 64).bytes);
+    try testing.expectEqual(Status.ok, wr(p, look_node, try std.fmt.bufPrint(&line, "{s}:99\n", .{path})).reply.status);
+    try testing.expectEqualStrings("         12          16 ", rd(p, dot, 0, 64).bytes);
+    try testing.expectEqualStrings("", rd(p, look_node, 0, 64).bytes);
+    try testing.expectStringStartsWith(p.panes[0].?.msg[0..p.panes[0].?.msg_len], "Look: ");
 }
 
 test "exec runs a builtin at the pane and records the pane it acted on" {