1 files changed, 44 insertions, 4 deletions
diff --git a/src/Messages.zig b/src/Messages.zig
index a316377a..366445c7 100644
--- a/src/Messages.zig
+++ b/src/Messages.zig
@@ -486,13 +486,53 @@ pub fn reportError(p: *Pardes, id: usize, operation: []const u8, err: anyerror)
         p.fs.no_pane_slot_len = @intCast(w.buffered().len);
         return reportFailure(p, id, w.buffered());
     }
-    for (@errorName(err), 0..) |c, i| {
-        if (std.ascii.isUpper(c) and i > 0) w.writeByte(' ') catch break;
-        w.writeByte(std.ascii.toLower(c)) catch break;
-    }
+    var words: [128]u8 = undefined;
+    w.writeAll(errorWords(err, &words)) catch {};
     reportFailure(p, id, w.buffered());
 }
 
+/// An error in a person's words, never its Zig name: the few that read
+/// badly spaced out said plainly, the rest spaced and lower case
+/// (`FileNotFound`, "file not found").
+pub fn errorWords(err: anyerror, buf: []u8) []const u8 {
+    return switch (err) {
+        error.FileTooLarge => "too large",
+        error.NotAFile => "not a regular file",
+        error.ReadFailed => "could not be read",
+        error.ParseZon => "not valid ZON",
+        error.ThemeFileTooLarge => "too large: a theme file is at most 1 MiB",
+        error.InvalidThemeName => "its name is empty or over 255 bytes",
+        else => {
+            var w = std.Io.Writer.fixed(buf);
+            for (@errorName(err), 0..) |c, i| {
+                if (std.ascii.isUpper(c) and i > 0) w.writeByte(' ') catch break;
+                w.writeByte(std.ascii.toLower(c)) catch break;
+            }
+            return w.buffered();
+        },
+    };
+}
+
+/// A ZON parse failure in a person's words: the first error the parser
+/// found and its line, `line 3: expected ','`.
+pub fn zonWhy(diag: *const std.zon.parse.Diagnostics, buf: []u8) []const u8 {
+    var errors = diag.iterateErrors();
+    const first = errors.next() orelse return "not valid ZON";
+    const loc = first.getLocation(diag);
+    return std.fmt.bufPrint(buf, "line {d}: {f}", .{ loc.line + 1, first.fmtMessage(diag) }) catch "not valid ZON";
+}
+
+test "errors are said in words, and a ZON failure names its line" {
+    var buf: [128]u8 = undefined;
+    try std.testing.expectEqualStrings("file not found", errorWords(error.FileNotFound, &buf));
+    try std.testing.expectEqualStrings("too large", errorWords(error.FileTooLarge, &buf));
+    var diag: std.zon.parse.Diagnostics = .{};
+    defer diag.deinit(std.testing.allocator);
+    const T = struct { a: u8 };
+    try std.testing.expectError(error.ParseZon, std.zon.parse.fromSliceAlloc(T, std.testing.allocator, ".{\n .a = 1,\n .b = 2 }", &diag, .{}));
+    try std.testing.expect(std.mem.startsWith(u8, zonWhy(&diag, &buf), "line 3: "));
+}
+
 /// The longest start of `text` that fits `max` bytes and ends between
 /// words (or, with no space to cut at, between characters).
 pub fn clip(text: []const u8, max: usize) []const u8 {