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, 67 insertions, 21 deletions

diff --git a/src/look.zig b/src/look.zig
index 020aacb8..6cf01dd2 100644
--- a/src/look.zig
+++ b/src/look.zig
@@ -1142,14 +1142,49 @@ pub fn followPdfLink(p: *Pardes, id: usize, probe: *const panes.Pdf.WordProbe) v
     }
 }
 
+/// A look that found nothing: said on the message row, logged as an `err`
+/// record, and marked so that /look reads back nothing (ninep/ctl.zig run).
+fn missed(p: *Pardes, id: usize, comptime fmt: []const u8, args: anytype) void {
+    p.look_missed = true;
+    var said: [160]u8 = undefined;
+    const why = std.fmt.bufPrint(&said, fmt, args) catch "no match";
+    var msg: [176]u8 = undefined;
+    p.setMessage(id, std.fmt.bufPrint(&msg, "Look: {s}", .{why}) catch "Look: no match");
+    const serial = if (p.panes[id]) |pane| pane.serial else 0;
+    var rec: [200]u8 = undefined;
+    pardes.ctlfs.events.notePath(p, "err", std.fmt.bufPrint(&rec, "{d} look: {s}", .{ serial, why }) catch return);
+}
+
+/// After a look at `path:N` focused its pane: a line past the end focuses
+/// nothing, leaves no pane it opened, and is a miss; a bare line number
+/// selects the line, its newline included, as acme's does.
+fn settleLine(p: *Pardes, id: usize, path: []const u8, at: Spot, before: usize, opened: ?usize) void {
+    const shown = p.panes[p.active] orelse return;
+    const f = if (shown.file) |*file| file else return;
+    if (at.line > panes.File.nlines(p.gpa, f)) {
+        if (opened) |free| p.removePane(free, null) catch {};
+        if (p.panes[before] != null) p.active = before;
+        return missed(p, id, "{s} has no line {d}", .{ path, at.line });
+    }
+    if (at.line > 0 and at.col == 0 and at.end_line == 0) {
+        const start = modal.lineStartOffset(f.content, at.line - 1);
+        const next = std.mem.indexOfScalarPos(u8, f.content, start, '\n');
+        const end = if (next) |i| i + 1 else f.content.len;
+        @import("ninep/pane.zig").setDot(shown, .{ .q0 = @intCast(start), .q1 = @intCast(end) });
+    }
+}
+
 /// `file:addr` or `:addr`, acme's look.c:450-543: a colon followed by an
 /// address character (addr.c:28, isaddrc) that is not a line spot this
 /// parser already reads (`file:12`, `file:12:5`). Not a URL.
 fn addressed(tok: []const u8) ?struct { path: []const u8, expr: []const u8 } {
     if (std.mem.indexOf(u8, tok, "://") != null) return null;
-    if (std.mem.indexOfAny(u8, tok, " \t") != null) return null;
     const colon = std.mem.indexOfScalar(u8, tok, ':') orelse return null;
     const expr = tok[colon + 1 ..];
+    // A written look is a whole line: the path has no blanks, but a
+    // pattern in the address may (`calc.py:/return a/`).
+    if (std.mem.indexOfAny(u8, tok[0..colon], " \t") != null) return null;
+    if (std.mem.indexOfAny(u8, expr, " \t") != null and std.mem.indexOfAny(u8, expr, "/?") == null) return null;
     if (expr.len == 0 or std.mem.indexOfScalar(u8, "0123456789+-/$.#,;", expr[0]) == null) return null;
     if (std.ascii.isDigit(expr[0])) {
         const pl = parsePathLine(tok);
@@ -1177,12 +1212,10 @@ fn lookAddress(p: *Pardes, id: usize, path: []const u8, expr: []const u8) void {
     if (path.len > 0 and (f.output != null or !std.mem.endsWith(u8, f.path, std.fs.path.basename(path)))) return;
     var a: Addr = .{ .text = f.content, .lim = null, .expr = expr };
     const r = a.address(ninep_pane.dotOf(pane)) orelse {
-        var said: [128]u8 = undefined;
-        return p.setMessage(id, std.fmt.bufPrint(&said, "Look: {s}", .{a.err}) catch "Look: bad address");
+        return missed(p, id, "{s}", .{a.err});
     };
     if (a.i < expr.len or r.q0 > r.q1) {
-        var said: [128]u8 = undefined;
-        return p.setMessage(id, std.fmt.bufPrint(&said, "Look: {s}", .{if (r.q0 > r.q1) "addresses out of order" else "bad address syntax"}) catch "Look: bad address");
+        return missed(p, id, "{s}", .{if (r.q0 > r.q1) "addresses out of order" else "bad address syntax"});
     }
     clearNavigationSelection(p, pane);
     ninep_pane.setDot(pane, r);
@@ -1209,6 +1242,10 @@ pub fn lookAt(p: *Pardes, id: usize, operand: []const u8) void {
     if (comptime pdf_enabled) if (panes.Pdf.lookSection(p, id, pl.path, pl.at)) return;
     var realbuf: [4096]u8 = undefined;
     const found = resolveLookTarget(p, id, txt, &realbuf);
+    // A line past the end of an open pane is a miss (the target's line is
+    // already clamped, so the one written is asked).
+    if (found == .pane and found.pane.id < MAX_PANES) if (p.panes[found.pane.id]) |shown| if (shown.file) |*f| if (pl.at.line > panes.File.nlines(p.gpa, f))
+        return missed(p, id, "{s} has no line {d}", .{ trimmed, pl.at.line });
     // A miss changes nothing, the selection included; anything else starts
     // from a clean one.
     if (found != .none) clearNavigationSelection(p, pane);
@@ -1219,10 +1256,7 @@ pub fn lookAt(p: *Pardes, id: usize, operand: []const u8) void {
                 p.reportError(id, "search", err);
                 return;
             };
-            if (rows == 0) {
-                var said: [96]u8 = undefined;
-                return p.setMessage(id, std.fmt.bufPrint(&said, "Look: no match for \"{s}\"", .{@import("Messages.zig").clip(trimmed, 48)}) catch "Look: no match");
-            }
+            if (rows == 0) return missed(p, id, "no match for \"{s}\"", .{@import("Messages.zig").clip(trimmed, 48)});
             clearNavigationSelection(p, pane);
             const at = pane.search_row;
             _ = searchStep(p, id, 1);
@@ -1235,8 +1269,10 @@ pub fn lookAt(p: *Pardes, id: usize, operand: []const u8) void {
         .pane => |t| {
             if (t.id >= MAX_PANES) return;
             const target = p.panes[t.id] orelse return;
+            const before = p.active;
             clearNavigationSelection(p, target);
             focusPaneLine(p, t.id, t.at, .center);
+            settleLine(p, id, trimmed, t.at, before, null);
         },
         .url => |u| if (u.len <= 256) p.emit(.{ .open_link = .from(u) }),
         .dir => |dir| {
@@ -1267,20 +1303,30 @@ pub fn lookAt(p: *Pardes, id: usize, operand: []const u8) void {
                 exec.placeDoc(p, id, free, nt);
                 return;
             };
+            // An open pane on this path too short for the line: a miss that
+            // touches nothing.
+            if (openPaneTarget(p, target.path, target.at)) |open| if (p.panes[open.pane.id].?.file) |*f|
+                if (target.at.line > panes.File.nlines(p.gpa, f))
+                    return missed(p, id, "{s} has no line {d}", .{ target.path, target.at.line });
             // focus an existing pane on this path (rescrolled), else open
-            if (focusPaneByPath(p, target.path, target.at)) return;
-            const free = p.freeSlot() orelse return p.reportError(id, "look", error.NoPaneSlots);
-            const nt = panes.File.open(p, free, target.path, target.at.line) catch |err|
-                return p.reportError(id, "look", err);
-            if (target.at.col > 0) nt.body.cur_col = @intCast(target.at.col - 1);
-            exec.placeDoc(p, id, free, nt);
-            layout.compute(p);
-            nt.file.?.scroll -|= @max(1, p.rects[free].h -| BOX_H) / 2;
-            if (target.at.end_line != 0) {
-                const centered = nt.file.?.scroll;
-                selectSpan(p, nt, target.at);
-                nt.file.?.scroll = centered;
+            const before = p.active;
+            var opened: ?usize = null;
+            if (!focusPaneByPath(p, target.path, target.at)) {
+                const free = p.freeSlot() orelse return p.reportError(id, "look", error.NoPaneSlots);
+                const nt = panes.File.open(p, free, target.path, target.at.line) catch |err|
+                    return p.reportError(id, "look", err);
+                if (target.at.col > 0) nt.body.cur_col = @intCast(target.at.col - 1);
+                exec.placeDoc(p, id, free, nt);
+                layout.compute(p);
+                nt.file.?.scroll -|= @max(1, p.rects[free].h -| BOX_H) / 2;
+                if (target.at.end_line != 0) {
+                    const centered = nt.file.?.scroll;
+                    selectSpan(p, nt, target.at);
+                    nt.file.?.scroll = centered;
+                }
+                opened = free;
             }
+            settleLine(p, id, target.path, target.at, before, opened);
         },
         .image => |target| {
             if (focusPaneByPath(p, target.path, .{})) return;