Added .packed and .align helpers to struct and @struct

Author: james-pre

src/decorators.ts

@@ -148,6 +148,16 @@ export function struct(name: string, ...options: Options[]) {
 	};
 }
 
+struct.packed = function (name: string, ...options: Options[]) {
+	return struct(name, ...options, { isPacked: true });
+};
+
+struct.align = function (alignment: number) {
+	return function (name: string, ...options: Options[]) {
+		return struct(name, ...options, { alignment });
+	};
+};
+
 /**
  * deprecated Use the new `union` function instead.
  */

src/structs.ts

@@ -143,7 +143,7 @@ export function struct<const T extends Record<string, FieldConfigInit>>(
 	return _struct;
 }
 
-struct.extend = function <const T extends Record<string, FieldConfigInit<Type<unknown>>>, const Base extends {}>(
+struct.extend = function <const T extends Record<string, FieldConfigInit>, const Base extends {}>(
 	base: StructConstructor<Base>,
 	structName: string,
 	fieldDecls: T,
@@ -152,6 +152,24 @@ struct.extend = function <const T extends Record<string, FieldConfigInit<Type<un
 	return struct<typeof base.fields & T>(structName, { ...base.fields, ...fieldDecls }, ...options);
 };
 
+struct.packed = function <const T extends Record<string, FieldConfigInit>>(
+	structName: string,
+	fieldDecls: T,
+	...options: Options[]
+): StructConstructor<StructValue<T>> {
+	return struct(structName, fieldDecls, ...options, { isPacked: true });
+};
+
+struct.align = function (alignment: number) {
+	return function <const T extends Record<string, FieldConfigInit>>(
+		structName: string,
+		fieldDecls: T,
+		...options: Options[]
+	): StructConstructor<StructValue<T>> {
+		return struct(structName, fieldDecls, ...options, { alignment });
+	};
+};
+
 export function union<const T extends Record<string, FieldConfigInit>>(
 	unionName: string,
 	fieldDecls: T,

tests/struct-decorators-dynamic.test.ts

@@ -2,11 +2,10 @@ import assert from 'node:assert';
 import { closeSync, openSync, readSync, writeFileSync } from 'node:fs';
 import { join } from 'node:path';
 import { encodeASCII } from 'utilium/string.js';
-import { sizeof } from '../src/misc.js';
 import { $from, field, struct, types as t } from '../src/decorators.js';
-import { packed } from '../src/attributes.js';
+import { sizeof } from '../src/misc.js';
 
-@struct(packed)
+@struct.packed('Duck')
 class Duck extends $from.typed(Uint8Array) {
 	@t.uint8 public accessor name_length: number = 0;
 	@t.char(64, { countedBy: 'name_length' }) public accessor name!: Uint8Array;
@@ -17,7 +16,7 @@ class Duck extends $from.typed(Uint8Array) {
 
 assert.equal(sizeof(Duck), 77);
 
-@struct(packed)
+@struct.packed('MamaDuck')
 class MamaDuck extends Duck {
 	@t.uint16 public accessor n_ducklings: number = 0;
 

tests/struct-decorators.test.ts

@@ -3,7 +3,6 @@ import assert from 'node:assert';
 import { join } from 'path';
 import { BufferView } from 'utilium/buffer.js';
 import { decodeASCII, encodeASCII } from 'utilium/string.js';
-import { packed } from '../src/attributes.js';
 import { $from, field, struct, types as t } from '../src/decorators.js';
 import { array } from '../src/fields.js';
 import { sizeof } from '../src/misc.js';
@@ -13,7 +12,7 @@ enum Some {
 	one = 2,
 }
 
-@struct(packed)
+@struct.packed('Header')
 class Header extends $from(BufferView) {
 	@t.char(4) public accessor magic_start = encodeASCII('test');
 
@@ -24,7 +23,7 @@ class Header extends $from(BufferView) {
 
 assert.equal(sizeof(Header), 10);
 
-@struct(packed)
+@struct.packed('AnotherHeader')
 class AnotherHeader extends Header {
 	@t.uint64 public accessor _plus: bigint = 0x12345678n;
 
@@ -33,15 +32,15 @@ class AnotherHeader extends Header {
 
 assert.equal(sizeof(AnotherHeader), sizeof(Header) + 10);
 
-@struct(packed)
+@struct.packed('Segment')
 class Segment extends $from(BufferView) {
 	@t.uint64 public accessor id = 0x021;
 	@t.uint32(64) public accessor data: ArrayLike<number> = [];
 }
 
 assert.equal(sizeof(Segment), 264);
 
-@struct(packed)
+@struct.packed('BinObject')
 class BinObject extends $from(Uint8Array) {
 	@field(AnotherHeader) public accessor header = new AnotherHeader();