From 284627e0d206eb0838321c15a4188555d7810458 Mon Sep 17 00:00:00 2001
From: sfja <sfja2004@gmail.com>
Date: Fri, 13 Mar 2026 00:23:33 +0100
Subject: [PATCH] add array initializer syntax

---
 src/middle.ts                           |  9 +++++++++
 src/mir_interpreter.ts                  | 19 ++++++++++++++++++-
 tests/{_array.ethlang => array.ethlang} |  0
 3 files changed, 27 insertions(+), 1 deletion(-)
 rename tests/{_array.ethlang => array.ethlang} (100%)

diff --git a/src/middle.ts b/src/middle.ts
index 4aa10e6..1152fa2 100644
--- a/src/middle.ts
+++ b/src/middle.ts
@@ -166,6 +166,12 @@ class FnLowerer {
         if (expr.is("IntExpr")) {
             return this.pushInst(Ty.Int, "Int", { value: expr.kind.value });
         }
+        if (expr.is("ArrayExpr")) {
+            const ty = this.checker.check(expr);
+            const values = expr.kind.values
+                .map((value) => this.lowerExpr(value));
+            return this.pushInst(ty, "Array", { values });
+        }
         if (expr.is("CallExpr")) {
             const ty = this.checker.check(expr);
             const args = expr.kind.args
@@ -407,6 +413,8 @@ export class Inst {
                     case "Int":
                     case "Bool":
                         return ` ${k.value}`;
+                    case "Array":
+                        return ` [${k.values.map(r).join(", ")}]`;
                     case "Fn":
                         return ` ${k.fn.stmt.kind.ident}`;
                     case "Param":
@@ -461,6 +469,7 @@ export type InstKind =
     | { tag: "Void" }
     | { tag: "Int"; value: number }
     | { tag: "Bool"; value: boolean }
+    | { tag: "Array"; values: Inst[] }
     | { tag: "Fn"; fn: Fn }
     | { tag: "Param"; idx: number }
     | { tag: "Call"; callee: Inst; args: Inst[] }
diff --git a/src/mir_interpreter.ts b/src/mir_interpreter.ts
index f5369c4..bb74c4a 100644
--- a/src/mir_interpreter.ts
+++ b/src/mir_interpreter.ts
@@ -24,6 +24,19 @@ export class FnInterpreter {
                 case "Void":
                 case "Int":
                 case "Bool":
+                    this.regs.set(inst, new Val(k));
+                    break;
+                case "Array":
+                    this.regs.set(
+                        inst,
+                        new Val({
+                            tag: "Array",
+                            values: k.values.map((inst) =>
+                                this.regs.get(inst)!
+                            ),
+                        }),
+                    );
+                    break;
                 case "Fn":
                     this.regs.set(inst, new Val(k));
                     break;
@@ -201,7 +214,7 @@ class Val {
 
     static Void = new Val({ tag: "Void" });
 
-    pretty() {
+    pretty(): string {
         const k = this.kind;
         switch (k.tag) {
             case "Null":
@@ -213,11 +226,14 @@ class Val {
                 return `${k.value}`;
             case "Ptr":
                 return `<pointer>`;
+            case "Array":
+                return `[${k.values.map((v) => v.pretty()).join(", ")}]`;
             case "Fn":
                 return `<${k.fn.ty.pretty()}>`;
             default:
                 k satisfies never;
         }
+        throw new Error();
     }
 }
 
@@ -227,4 +243,5 @@ type ValKind =
     | { tag: "Int"; value: number }
     | { tag: "Bool"; value: boolean }
     | { tag: "Ptr"; mutable: boolean; value: Val }
+    | { tag: "Array"; values: Val[] }
     | { tag: "Fn"; fn: mir.Fn };
diff --git a/tests/_array.ethlang b/tests/array.ethlang
similarity index 100%
rename from tests/_array.ethlang
rename to tests/array.ethlang