Merge pull request #110 from getty-zig/untagged-representation

Add support for the untagged representation of unions

src/attributes.zig

@@ -2,7 +2,7 @@ const std = @import("std");
 const comptimePrint = std.fmt.comptimePrint;
 const Type = std.builtin.Type;
 
-/// Case conventions for the `rename_all` attribute.
+/// Case conventions.
 pub const Case = enum {
     // foobar
     lower,
@@ -29,6 +29,13 @@ pub const Case = enum {
     screaming_kebab,
 };
 
+/// Tag representations for union variants.
+pub const Tag = enum {
+    external,
+    internal,
+    untagged,
+};
+
 /// Returns an attribute map type.
 pub fn Attributes(comptime T: type, comptime attributes: anytype) type {
     const type_name = @typeName(T);
@@ -171,9 +178,8 @@ const ContainerAttributes = struct {
     // convention.
     //rename_all: ?Case = null,
 
-    // Use the internally tagged enum representation for this enum, with
-    // the given tag.
-    //tag: ?[]const u8 = null,
+    // Use the specified representation for this union.
+    tag: Tag = .external,
 
     // Deserialize this type by deserializing into the given type, then
     // converting fallibly.

src/de/blocks/struct.zig

@@ -91,7 +91,7 @@ test "deserialize - struct" {
 
     inline for (tests) |t| {
         const Want = @TypeOf(t.want);
-        const got = try testing.deserialize(null, t.name, Self, Want, t.tokens);
+        const got = try testing.deserialize(std.testing.allocator, t.name, Self, Want, t.tokens);
         try testing.expectEqual(t.name, t.want, got);
     }
 }
@@ -252,12 +252,12 @@ test "deserialize - struct, attributes" {
             try testing.expectError(
                 t.name,
                 t.want_err,
-                testing.deserializeErr(null, Self, Want, t.tokens),
+                testing.deserializeErr(std.testing.allocator, Self, Want, t.tokens),
             );
         } else {
             const Want = @TypeOf(t.want);
 
-            const got = try testing.deserialize(null, t.name, Self, Want, t.tokens);
+            const got = try testing.deserialize(std.testing.allocator, t.name, Self, Want, t.tokens);
             try testing.expectEqual(t.name, t.want, got);
         }
     }