config: ability to format all field types except tagged unions

src/config/Config.zig

@@ -2178,6 +2178,19 @@ pub const Color = packed struct(u24) {
         return std.meta.eql(self, other);
     }
 
+    /// Used by Formatter
+    pub fn formatEntry(self: Color, formatter: anytype) !void {
+        var buf: [128]u8 = undefined;
+        try formatter.formatEntry(
+            []const u8,
+            std.fmt.bufPrint(
+                &buf,
+                "#{x:0>2}{x:0>2}{x:0>2}",
+                .{ self.r, self.g, self.b },
+            ) catch return error.OutOfMemory,
+        );
+    }
+
     /// fromHex parses a color from a hex value such as #RRGGBB. The "#"
     /// is optional.
     pub fn fromHex(input: []const u8) !Color {
@@ -2251,6 +2264,21 @@ pub const Palette = struct {
         return std.meta.eql(self, other);
     }
 
+    /// Used by Formatter
+    pub fn formatEntry(self: Self, formatter: anytype) !void {
+        var buf: [128]u8 = undefined;
+        for (0.., self.value) |k, v| {
+            try formatter.formatEntry(
+                []const u8,
+                std.fmt.bufPrint(
+                    &buf,
+                    "{d}=#{x:0>2}{x:0>2}{x:0>2}",
+                    .{ k, v.r, v.g, v.b },
+                ) catch return error.OutOfMemory,
+            );
+        }
+    }
+
     test "parseCLI" {
         const testing = std.testing;
 
@@ -2314,6 +2342,19 @@ pub const RepeatableString = struct {
         } else return true;
     }
 
+    /// Used by Formatter
+    pub fn formatEntry(self: Self, formatter: anytype) !void {
+        // If no items, we want to render an empty field.
+        if (self.list.items.len == 0) {
+            try formatter.formatEntry(void, {});
+            return;
+        }
+
+        for (self.list.items) |value| {
+            try formatter.formatEntry([]const u8, value);
+        }
+    }
+
     test "parseCLI" {
         const testing = std.testing;
         var arena = ArenaAllocator.init(testing.allocator);
@@ -2355,6 +2396,11 @@ pub const RepeatablePath = struct {
         return self.value.equal(other.value);
     }
 
+    /// Used by Formatter
+    pub fn formatEntry(self: Self, formatter: anytype) !void {
+        try self.value.formatEntry(formatter);
+    }
+
     /// Expand all the paths relative to the base directory.
     pub fn expand(
         self: *Self,
@@ -2442,6 +2488,26 @@ pub const RepeatableFontVariation = struct {
         } else return true;
     }
 
+    /// Used by Formatter
+    pub fn formatEntry(
+        self: Self,
+        formatter: anytype,
+    ) !void {
+        if (self.list.items.len == 0) {
+            try formatter.formatEntry(void, {});
+            return;
+        }
+
+        var buf: [128]u8 = undefined;
+        for (self.list.items) |value| {
+            const str = std.fmt.bufPrint(&buf, "{s}={d}", .{
+                value.id.str(),
+                value.value,
+            }) catch return error.OutOfMemory;
+            try formatter.formatEntry([]const u8, str);
+        }
+    }
+
     test "parseCLI" {
         const testing = std.testing;
         var arena = ArenaAllocator.init(testing.allocator);
@@ -2561,6 +2627,29 @@ pub const Keybinds = struct {
         return true;
     }
 
+    /// Used by Formatter
+    pub fn formatEntry(self: Keybinds, formatter: anytype) !void {
+        if (self.set.bindings.size == 0) {
+            try formatter.formatEntry(void, {});
+            return;
+        }
+
+        var buf: [1024]u8 = undefined;
+        var iter = self.set.bindings.iterator();
+        while (iter.next()) |next| {
+            const k = next.key_ptr.*;
+            const v = next.value_ptr.*;
+            try formatter.formatEntry(
+                []const u8,
+                std.fmt.bufPrint(
+                    &buf,
+                    "{}={}",
+                    .{ k, v },
+                ) catch return error.OutOfMemory,
+            );
+        }
+    }
+
     test "parseCLI" {
         const testing = std.testing;
         var arena = ArenaAllocator.init(testing.allocator);
@@ -2618,6 +2707,49 @@ pub const RepeatableCodepointMap = struct {
         } else return true;
     }
 
+    /// Used by Formatter
+    pub fn formatEntry(
+        self: Self,
+        formatter: anytype,
+    ) !void {
+        if (self.map.list.len == 0) {
+            try formatter.formatEntry(void, {});
+            return;
+        }
+
+        var buf: [1024]u8 = undefined;
+        const ranges = self.map.list.items(.range);
+        const descriptors = self.map.list.items(.descriptor);
+        for (ranges, descriptors) |range, descriptor| {
+            if (range[0] == range[1]) {
+                try formatter.formatEntry(
+                    []const u8,
+                    std.fmt.bufPrint(
+                        &buf,
+                        "U+{X:0>4}={s}",
+                        .{
+                            range[0],
+                            descriptor.family orelse "",
+                        },
+                    ) catch return error.OutOfMemory,
+                );
+            } else {
+                try formatter.formatEntry(
+                    []const u8,
+                    std.fmt.bufPrint(
+                        &buf,
+                        "U+{X:0>4}-U{X:0>4}={s}",
+                        .{
+                            range[0],
+                            range[1],
+                            descriptor.family orelse "",
+                        },
+                    ) catch return error.OutOfMemory,
+                );
+            }
+        }
+    }
+
     /// Parses the list of Unicode codepoint ranges. Valid syntax:
     ///
     ///   "" (empty returns null)
@@ -2836,6 +2968,13 @@ pub const RepeatableLink = struct {
         _ = other;
         return true;
     }
+
+    /// Used by Formatter
+    pub fn formatEntry(self: Self, formatter: anytype) !void {
+        // This currently can't be set so we don't format anything.
+        _ = self;
+        _ = formatter;
+    }
 };
 
 /// Options for copy on select behavior.

src/config/formatter.zig

@@ -19,7 +19,7 @@ pub const FileFormatter = struct {
 
         inline for (@typeInfo(Config).Struct.fields) |field| {
             if (field.name[0] == '_') continue;
-            try self.formatField(
+            try self.formatEntry(
                 field.type,
                 field.name,
                 @field(self.config, field.name),
@@ -28,13 +28,32 @@ pub const FileFormatter = struct {
         }
     }
 
-    fn formatField(
+    pub fn formatEntry(
         self: FileFormatter,
         comptime T: type,
         name: []const u8,
         value: T,
         writer: anytype,
     ) !void {
+        const EntryFormatter = struct {
+            parent: *const FileFormatter,
+            name: []const u8,
+            writer: @TypeOf(writer),
+
+            pub fn formatEntry(
+                self_entry: @This(),
+                comptime EntryT: type,
+                value_entry: EntryT,
+            ) !void {
+                return self_entry.parent.formatEntry(
+                    EntryT,
+                    self_entry.name,
+                    value_entry,
+                    self_entry.writer,
+                );
+            }
+        };
+
         switch (@typeInfo(T)) {
             .Bool, .Int => {
                 try writer.print("{s} = {}\n", .{ name, value });
@@ -46,8 +65,19 @@ pub const FileFormatter = struct {
                 return;
             },
 
-            .Optional => |info| if (value) |inner| {
-                try self.formatField(
+            .Enum => {
+                try writer.print("{s} = {s}\n", .{ name, @tagName(value) });
+                return;
+            },
+
+            .Void => {
+                try writer.print("{s} = \n", .{name});
+                return;
+            },
+
+            .Optional => |info| {
+                if (value) |inner| {
+                    try self.formatEntry(
                         info.child,
                         name,
                         inner,
@@ -55,6 +85,9 @@ pub const FileFormatter = struct {
                     );
                 } else {
                     try writer.print("{s} = \n", .{name});
+                }
+
+                return;
             },
 
             .Pointer => switch (T) {
@@ -62,16 +95,51 @@ pub const FileFormatter = struct {
                 [:0]const u8,
                 => {
                     try writer.print("{s} = {s}\n", .{ name, value });
+                    return;
                 },
 
                 else => {},
             },
 
+            // Structs of all types require a "formatEntry" function
+            // to be defined which will be called to format the value.
+            // This is given the formatter in use so that they can
+            // call BACK to our formatEntry to write each primitive
+            // value.
+            .Struct => |info| if (@hasDecl(T, "formatEntry")) {
+                try value.formatEntry(EntryFormatter{
+                    .parent = &self,
+                    .name = name,
+                    .writer = writer,
+                });
+                return;
+            } else switch (info.layout) {
+                // Packed structs we special case.
+                .Packed => {
+                    try writer.print("{s} = ", .{name});
+                    inline for (info.fields, 0..) |field, i| {
+                        if (i > 0) try writer.print(",", .{});
+                        try writer.print("{s}{s}", .{
+                            if (!@field(value, field.name)) "no-" else "",
+                            field.name,
+                        });
+                    }
+                    try writer.print("\n", .{});
+                    return;
+                },
+
+                else => {},
+            },
+
+            // TODO
+            .Union => return,
+
             else => {},
         }
 
-        // TODO: make a compiler error so we can detect when
-        // we don't support a type.
+        // Compile error so that we can catch missing cases.
+        @compileLog(T);
+        @compileError("missing case for type");
     }
 };