WIP: Formatter

src/Class.zig

@@ -1,11 +1,9 @@
 const std = @import("std");
 
 const EnumFlags = @import("EnumFlags.zig").EnumFlags;
+const Formatter = @import("Formatter.zig");
 
-pub const FieldInfo = @import("Class/FieldInfo.zig");
-pub const MethodInfo = @import("Class/MethodInfo.zig");
-pub const AttributeInfo = @import("Class/AttributeInfo.zig").AttributeInfo;
-pub const ConstantPool = @import("Class/ConstantPool.zig");
+allocator: std.mem.Allocator,
 
 magic: u32,
 minor_version: u16,
@@ -21,6 +19,11 @@ attributes: []AttributeInfo,
 
 const Self = @This();
 
+pub const FieldInfo = @import("Class/FieldInfo.zig");
+pub const MethodInfo = @import("Class/MethodInfo.zig");
+pub const AttributeInfo = @import("Class/AttributeInfo.zig").AttributeInfo;
+pub const ConstantPool = @import("Class/ConstantPool.zig");
+
 pub const ClassAccessFlags = EnumFlags(enum(u16) {
     public = 0x0001,
     final = 0x0010,
@@ -55,7 +58,7 @@ pub fn parse(input: *std.Io.Reader, allocator: std.mem.Allocator) (ParseError ||
     var constant_pool: ConstantPool = try .parse(input, allocator);
     errdefer constant_pool.deinit(allocator);
 
-    const access_flags: ClassAccessFlags = .from(try input.takeInt(u16, .big));
+    const access_flags: ClassAccessFlags = .{ .mask = try input.takeInt(u16, .big) };
 
     const this_class = try input.takeInt(u16, .big);
     const super_class = try input.takeInt(u16, .big);
@@ -88,6 +91,7 @@ pub fn parse(input: *std.Io.Reader, allocator: std.mem.Allocator) (ParseError ||
     }
 
     return .{
+        .allocator = allocator,
         .magic = magic,
         .minor_version = minor_version,
         .major_version = major_version,
@@ -150,37 +154,37 @@ pub fn parseAttributes(input: *std.Io.Reader, constant_pool: ConstantPool, alloc
     return attributes;
 }
 
-pub fn deinit(self: *Self, allocator: std.mem.Allocator) void {
-    self.constant_pool.deinit(allocator);
-    self.freeInterfaces(allocator);
-    self.freeFields(allocator);
-    self.freeMethods(allocator);
-    self.freeAttributes(allocator);
+pub fn deinit(self: *Self) void {
+    self.constant_pool.deinit(self.allocator);
+    self.freeInterfaces();
+    self.freeFields();
+    self.freeMethods();
+    self.freeAttributes();
 }
 
-fn freeInterfaces(self: *Self, allocator: std.mem.Allocator) void {
-    allocator.free(self.interfaces);
+fn freeInterfaces(self: *Self) void {
+    self.allocator.free(self.interfaces);
 }
 
-fn freeFields(self: *Self, allocator: std.mem.Allocator) void {
+fn freeFields(self: *Self) void {
     for (self.fields) |*field_info| {
-        field_info.deinit(allocator);
+        field_info.deinit(self.allocator);
     }
-    allocator.free(self.fields);
+    self.allocator.free(self.fields);
 }
 
-fn freeMethods(self: *Self, allocator: std.mem.Allocator) void {
+fn freeMethods(self: *Self) void {
     for (self.methods) |*method_info| {
-        method_info.deinit(allocator);
+        method_info.deinit(self.allocator);
     }
-    allocator.free(self.methods);
+    self.allocator.free(self.methods);
 }
 
-fn freeAttributes(self: *Self, allocator: std.mem.Allocator) void {
+fn freeAttributes(self: *Self) void {
     for (self.attributes) |*attr| {
-        attr.deinit(allocator);
+        attr.deinit(self.allocator);
     }
-    allocator.free(self.attributes);
+    self.allocator.free(self.attributes);
 }
 
 pub fn jsonStringify(self: *const Self, jws: *std.json.Stringify) !void {
@@ -195,6 +199,10 @@ pub fn jsonStringify(self: *const Self, jws: *std.json.Stringify) !void {
     try jws.endObject();
 }
 
+pub fn acceptFormatter(self: *const Self, formatter: *Formatter) Formatter.Error!void {
+    try formatter.printField("magic", "0x{X}", .{ self.magic });
+}
+
 pub fn format(self: *const Self, w: *std.Io.Writer) std.Io.Writer.Error!void {
     const depth = 2;
     var indent: u8 = 0;

src/Class/AttributeInfo.zig

@@ -625,7 +625,7 @@ pub const AttributeInfo = union(enum) {
 
                             try w.splatByteAll(' ', depth * component_indent);
                             try w.print("{d}:\n", .{ i });
-                            try component.indentedFormat(w, depth, component_indent + 1, constant_pool);
+                            try component.indentedFormat(w, depth, component_indent, constant_pool);
                         }
                     },
                     .permitted_subclasses => |attr| {
@@ -1200,7 +1200,7 @@ pub const InnerClasses = struct {
                 .inner_class_info_index = try input.takeInt(u16, .big),
                 .outer_class_info_index = try input.takeInt(u16, .big),
                 .inner_name_index = try input.takeInt(u16, .big),
-                .inner_class_access_flags = .from(try input.takeInt(u16, .big)),
+                .inner_class_access_flags = .{ .mask = try input.takeInt(u16, .big) },
             };
         }
 
@@ -2491,7 +2491,7 @@ pub const MethodParameters = struct {
         for (parameters) |*parameter| {
             parameter.* = .{
                 .name_index = try input.takeInt(u16, .big),
-                .access_flags = .from(try input.takeInt(u16, .big)),
+                .access_flags = .{ .mask = try input.takeInt(u16, .big) },
             };
         }
 
@@ -2695,7 +2695,7 @@ pub const Module = struct {
 
     pub fn parse(input: *std.Io.Reader, allocator: std.mem.Allocator) ParseError!Self {
         const module_name_index = try input.takeInt(u16, .big);
-        const module_flags: ModuleFlags = .from(try input.takeInt(u16, .big));
+        const module_flags: ModuleFlags = .{ .mask = try input.takeInt(u16, .big) };
         const module_version_index = try input.takeInt(u16, .big);
 
         const requires_count = try input.takeInt(u16, .big);
@@ -2703,7 +2703,7 @@ pub const Module = struct {
         errdefer allocator.free(requires);
         for (requires) |*r| {
             const requires_index = try input.takeInt(u16, .big);
-            const requires_flags: Requires.RequiresFlags = .from(try input.takeInt(u16, .big));
+            const requires_flags: Requires.RequiresFlags = .{ .mask = try input.takeInt(u16, .big) };
             const requires_version_index = try input.takeInt(u16, .big);
             r.* = .{
                 .requires_index = requires_index,
@@ -2717,7 +2717,7 @@ pub const Module = struct {
         errdefer allocator.free(exports);
         for (exports) |*e| {
             const exports_index = try input.takeInt(u16, .big);
-            const exports_flags: Exports.ExportsFlags = .from(try input.takeInt(u16, .big));
+            const exports_flags: Exports.ExportsFlags = .{ .mask = try input.takeInt(u16, .big) };
             const exports_to_count = try input.takeInt(u16, .big);
             const exports_to_indeces = try allocator.alloc(u16, exports_to_count);
             errdefer allocator.free(exports_to_indeces);
@@ -2736,7 +2736,7 @@ pub const Module = struct {
         errdefer allocator.free(opens);
         for (opens) |*o| {
             const opens_index = try input.takeInt(u16, .big);
-            const opens_flags: Opens.OpensFlags = .from(try input.takeInt(u16, .big));
+            const opens_flags: Opens.OpensFlags = .{ .mask = try input.takeInt(u16, .big) };
             const opens_to_count = try input.takeInt(u16, .big);
             const opens_to_indeces = try allocator.alloc(u16, opens_to_count);
             errdefer allocator.free(opens_to_indeces);

src/Class/FieldInfo.zig

@@ -27,7 +27,7 @@ pub const FieldAccessFlags = EnumFlags(enum(u16) {
 });
 
 pub fn parse(input: *std.Io.Reader, constant_pool: ConstantPool, allocator: std.mem.Allocator) !Self {
-    const access_flags: FieldAccessFlags = .from(try input.takeInt(u16, .big));
+    const access_flags: FieldAccessFlags = .{ .mask = try input.takeInt(u16, .big) };
     const name_index = try input.takeInt(u16, .big);
     const descriptor_index = try input.takeInt(u16, .big);
     const attributes = try Class.parseAttributes(input, constant_pool, allocator);

src/Class/MethodInfo.zig

@@ -30,7 +30,7 @@ pub const MethodAccessFlags = EnumFlags(enum(u16) {
 });
 
 pub fn parse(input: *std.Io.Reader, constant_pool: ConstantPool, allocator: std.mem.Allocator) !Self {
-    const access_flags: MethodAccessFlags = .from(try input.takeInt(u16, .big));
+    const access_flags: MethodAccessFlags = .{ .mask = try input.takeInt(u16, .big) };
     const name_index = try input.takeInt(u16, .big);
     const descriptor_index = try input.takeInt(u16, .big);
     const attributes = try Class.parseAttributes(input, constant_pool, allocator);

src/EnumFlags.zig

@@ -10,12 +10,6 @@ pub fn EnumFlags(comptime E: type) type {
 
         pub const empty: Self = .{ .data = 0 };
 
-        pub fn from(mask: BackingInt) Self {
-            return .{
-                .mask = mask,
-            };
-        }
-
         pub fn contains(self: Self, flag: E) bool {
             return (self.mask & @intFromEnum(flag)) != 0;
         }

src/Formatter.zig

@@ -0,0 +1,57 @@
+const std = @import("std");
+
+pub const Error = error {};
+
+vtable: *const VTable,
+w: *std.Io.Writer,
+
+const Self = @This();
+
+pub const VTable = struct {
+    printField: *const fn (
+        ptr: *Self,
+        comptime field: []const u8,
+        comptime fmt: []const u8,
+        args: anytype,
+    ) Error!void,
+};
+
+pub fn printField(
+    self: *const Self,
+    comptime field: []const u8,
+    value: anytype,
+) Error!void {
+    self.vtable.field(self, field);
+    self.vtable.value(self, value);
+}
+
+pub const IndentedFormatter = struct {
+    indent: u8 = 0,
+    depth: usize = 0,
+
+    interface: Self,
+
+    pub fn init(w: *std.Io.Writer) IndentedFormatter {
+        return .{
+            .interface = .{
+                .vtable = &.{
+                    .printField = IndentedFormatter.printField,
+                },
+                .w = w,
+            },
+        };
+    }
+
+    fn printField(
+        f: *Self,
+        comptime field: []const u8,
+        comptime fmt: []const u8,
+        args: anytype,
+    ) Error!void {
+        const self: *IndentedFormatter = @alignCast(@fieldParentPtr("interface", f));
+
+        _ = try self.interface.w.splatByteAll(' ', self.indent * self.depth);
+        try self.interface.w.print(field ++ ": " ++ fmt ++ "\n", args);
+    }
+};
+

src/main.zig

@@ -2,6 +2,8 @@ const std = @import("std");
 
 const Class = @import("Class.zig");
 
+const Formatter = @import("Formatter.zig");
+
 pub fn main(init: std.process.Init) !void {
     const io = init.io;
     const allocator = init.gpa;
@@ -50,9 +52,11 @@ pub fn main(init: std.process.Init) !void {
         },
         else => return err,
     };
-    defer class.deinit(allocator);
+    defer class.deinit();
 
-    try stdout.print("{f}", .{ class });
+    var indented_formatter: Formatter.IndentedFormatter = .init(stdout);
+    const formatter = &indented_formatter.interface;
+    try class.acceptFormatter(formatter);
 
     try stdout.flush();
 }

testsuite/classes/java/Record.java

@@ -1,2 +0,0 @@
-public record Record(String name, int age) {}
-