[VOI-33] Unions

package.json

@@ -27,7 +27,7 @@
     "@vitest/ui": "^2.0.5",
     "eslint": "^7.10.0",
     "ts-node": "^10.9.2",
-    "typescript": "^4.9.3",
+    "typescript": "^5.6.2",
     "vitest": "^2.0.5"
   },
   "dependencies": {

src/__tests__/compiler.test.ts

@@ -55,6 +55,7 @@ describe("E2E Compiler Pipeline", () => {
       17,
       82,
       3,
+      42,
     ]);
   });
 

src/__tests__/fixtures/e2e-file.ts

@@ -186,6 +186,29 @@ fn get_z_for_gen_str_ta(v: GenericStructuralTypeAlias<i32>) -> i32
 
 pub fn test16() -> i32
   get_z_for_gen_str_ta({ x: 1, y: 2, z: 3 })
+
+obj None {}
+obj Some<T> { value: T }
+
+type Optional<T> = Some<T> | None
+
+fn optional_match_chain()
+  let some: Optional<i32> = Some<i32> { value: 39 }
+
+  some
+    .match(x)
+      Some<i32>: Some<i32> { value: x.value + 1 }
+      None: None {}
+    .match(val)
+      Some<i32>: Some<i32> { value: val.value + 2 }
+      None: None {}
+
+pub fn test17()
+  let x = optional_match_chain()
+
+  match(x)
+    Some<i32>: x.value
+    None: -1
 `;
 
 export const tcoText = `

src/assembler.ts

@@ -10,6 +10,7 @@ import {
   ObjectType,
   DsArrayType,
   voidBaseObject,
+  UnionType,
 } from "./syntax-objects/types.js";
 import { Variable } from "./syntax-objects/variable.js";
 import { Block } from "./syntax-objects/block.js";
@@ -162,9 +163,22 @@ const compileMatch = (opts: CompileExprOpts<Match>) => {
     );
   };
 
-  return constructIfChain(
+  const ifChain = constructIfChain(
     expr.defaultCase ? [...expr.cases, expr.defaultCase] : expr.cases
   );
+
+  if (expr.bindVariable) {
+    return opts.mod.block(null, [
+      compileVariable({
+        ...opts,
+        isReturnExpr: false,
+        expr: expr.bindVariable,
+      }),
+      ifChain,
+    ]);
+  }
+
+  return ifChain;
 };
 
 const compileIdentifier = (opts: CompileExprOpts<Identifier>) => {
@@ -345,7 +359,7 @@ const compileFunction = (opts: CompileExprOpts<Fn>): number => {
     isReturnExpr: true,
   });
 
-  const variableTypes = getFunctionVarTypes(opts, fn); // TODO: Vars should probably be registered with the function type rather than body (for consistency).
+  const variableTypes = getFunctionVarTypes(opts, fn);
 
   mod.addFunction(fn.id, parameterTypes, returnType, variableTypes, body);
 
@@ -446,6 +460,7 @@ export const mapBinaryenType = (
   if (isPrimitiveId(type, "f64")) return binaryen.f64;
   if (isPrimitiveId(type, "void")) return binaryen.none;
   if (type.isObjectType()) return buildObjectType(opts, type);
+  if (type.isUnionType()) return buildUnionType(opts, type);
   if (type.isDsArrayType()) return buildDsArrayType(opts, type);
   throw new Error(`Unsupported type ${type}`);
 };
@@ -461,6 +476,18 @@ const buildDsArrayType = (opts: CompileExprOpts, type: DsArrayType) => {
   return type.binaryenType;
 };
 
+const buildUnionType = (opts: MapBinTypeOpts, union: UnionType): TypeRef => {
+  if (union.hasAttribute("binaryenType")) {
+    return union.getAttribute("binaryenType") as TypeRef;
+  }
+
+  union.types.forEach((type) => mapBinaryenType(opts, type));
+
+  const typeRef = mapBinaryenType(opts, voidBaseObject);
+  union.setAttribute("binaryenType", typeRef);
+  return typeRef;
+};
+
 // Marks the start of the fields in an object after RTT info fields
 const OBJECT_FIELDS_OFFSET = 2;
 

src/parser/__tests__/__snapshots__/parser.test.ts.snap

@@ -403,6 +403,52 @@ exports[`parser can parse a file into a syntax expanded ast 1`] = `
       ],
     ],
   ],
+  [
+    "match",
+    "x",
+    [
+      ":",
+      [
+        "Some",
+        [
+          "generics",
+          "i32",
+        ],
+      ],
+      [
+        "Some",
+        [
+          "generics",
+          "i32",
+        ],
+        [
+          "object",
+          [
+            ":",
+            "value",
+            [
+              "+",
+              [
+                "value",
+                "x",
+              ],
+              1,
+            ],
+          ],
+        ],
+      ],
+    ],
+    [
+      ":",
+      "None",
+      [
+        "None",
+        [
+          "object",
+        ],
+      ],
+    ],
+  ],
   [
     "fn",
     [

src/parser/__tests__/fixtures/void-file.ts

@@ -66,6 +66,10 @@ obj Test<T> {
   c: i32
 }
 
+match(x)
+  Some<i32>: Some<i32> { value: x.value + 1 }
+  None: None {}
+
 fn test<T>(a: 1) -> i32
 
 fn main()

src/parser/lexer.ts

@@ -67,7 +67,10 @@ export const lexer = (chars: CharStream): Token => {
 
 const consumeOperator = (chars: CharStream, token: Token) => {
   while (isOpChar(chars.next)) {
-    if (token.value === ">" && chars.next === ">") break; // Ugly hack to support generics, means >> is not a valid operator
+    if (token.value === ">" && (chars.next === ">" || chars.next === ":")) {
+      break; // Ugly hack to support generics, means >> is not a valid operator
+    }
+
     token.addChar(chars.consumeChar());
   }
 };