goose-lang · upamanyus · Feb 24, 2026 · Feb 23, 2026 · Feb 23, 2026 · Feb 23, 2026
diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
@@ -11,7 +11,7 @@ jobs:
   test:
     strategy:
       matrix:
-        go-version: ["1.25.x"]
+        go-version: ["1.26.x"]
         os: ["ubuntu-latest"]
     runs-on: ${{ matrix.os }}
     steps:

diff --git a/go.mod b/go.mod
@@ -1,6 +1,6 @@
 module github.com/goose-lang/goose
 
-go 1.25
+go 1.26
 
 require (
 	github.com/fatih/color v1.18.0

diff --git a/go.work b/go.work
@@ -1,4 +1,4 @@
-go 1.25.4
+go 1.26
 
 use (
 	.

diff --git a/goose.go b/goose.go
@@ -968,7 +968,8 @@ func (ctx *Ctx) indexExpr(e *ast.IndexExpr, multipleBindings bool) glang.Expr {
 
 	return glang.NewCallExpr(glang.VerbatimExpr("Index"),
 		ctx.glangType(e, ctx.typeOf(e.X)),
-		glang.TupleExpr{ctx.expr(e.X), ctx.expr(e.Index)})
+		glang.TupleExpr{ctx.expr(e.X),
+			ctx.exprIntoType(e.Index, types.Typ[types.Int])})
 }
 
 func (ctx *Ctx) indexListExpr(e *ast.IndexListExpr) glang.Expr {

diff --git a/testdata/examples/append_log/append_log.gold.v b/testdata/examples/append_log/append_log.gold.v
@@ -13,6 +13,8 @@ Module append_log.
 
 Definition Log {ext : ffi_syntax} {go_gctx : GoGlobalContext} : go.type := go.Named "github.com/goose-lang/goose/testdata/examples/append_log.Log"%go [].
 
+#[global] Opaque Log.
+
 Definition Init {ext : ffi_syntax} {go_gctx : GoGlobalContext} : go_string := "github.com/goose-lang/goose/testdata/examples/append_log.Init"%go.
 
 Definition Open {ext : ffi_syntax} {go_gctx : GoGlobalContext} : go_string := "github.com/goose-lang/goose/testdata/examples/append_log.Open"%go.

diff --git a/testdata/examples/channel/channel.gold.v b/testdata/examples/channel/channel.gold.v
@@ -12,14 +12,24 @@ Module chan_spec_raw_examples.
 
 Definition LockedStack {ext : ffi_syntax} {go_gctx : GoGlobalContext} : go.type := go.Named "github.com/goose-lang/goose/testdata/examples/channel.LockedStack"%go [].
 
+#[global] Opaque LockedStack.
+
 Definition EliminationStack {ext : ffi_syntax} {go_gctx : GoGlobalContext} : go.type := go.Named "github.com/goose-lang/goose/testdata/examples/channel.EliminationStack"%go [].
 
+#[global] Opaque EliminationStack.
+
 Definition request {ext : ffi_syntax} {go_gctx : GoGlobalContext} : go.type := go.Named "github.com/goose-lang/goose/testdata/examples/channel.request"%go [].
 
+#[global] Opaque request.
+
 Definition stream {ext : ffi_syntax} {go_gctx : GoGlobalContext} : go.type := go.Named "github.com/goose-lang/goose/testdata/examples/channel.stream"%go [].
 
+#[global] Opaque stream.
+
 Definition streamold {ext : ffi_syntax} {go_gctx : GoGlobalContext} : go.type := go.Named "github.com/goose-lang/goose/testdata/examples/channel.streamold"%go [].
 
+#[global] Opaque streamold.
+
 Definition timeout {ext : ffi_syntax} {go_gctx : GoGlobalContext} : val := #(W64 10000).
 
 Definition NewLockedStack {ext : ffi_syntax} {go_gctx : GoGlobalContext} : go_string := "github.com/goose-lang/goose/testdata/examples/channel.NewLockedStack"%go.

diff --git a/testdata/examples/comments/comments.gold.v b/testdata/examples/comments/comments.gold.v
@@ -9,6 +9,8 @@ Module comments.
 
 Definition Foo {ext : ffi_syntax} {go_gctx : GoGlobalContext} : go.type := go.Named "github.com/goose-lang/goose/testdata/examples/comments.Foo"%go [].
 
+#[global] Opaque Foo.
+
 Definition ONE {ext : ffi_syntax} {go_gctx : GoGlobalContext} : val := #(W64 1).
 
 Definition TWO {ext : ffi_syntax} {go_gctx : GoGlobalContext} : val := #(W64 2).

diff --git a/testdata/examples/go.mod b/testdata/examples/go.mod
@@ -1,6 +1,6 @@
 module github.com/goose-lang/goose/testdata/examples
 
-go 1.25
+go 1.26
 
 require (
 	github.com/goose-lang/primitive v0.2.2-0.20260212023729-cb7f52217e65

diff --git a/testdata/examples/interfacerecursion/interfacerecursion.gold.v b/testdata/examples/interfacerecursion/interfacerecursion.gold.v
@@ -9,10 +9,16 @@ Module interfacerecursion.
 
 Definition A {ext : ffi_syntax} {go_gctx : GoGlobalContext} : go.type := go.Named "github.com/goose-lang/goose/testdata/examples/interfacerecursion.A"%go [].
 
+#[global] Opaque A.
+
 Definition B {ext : ffi_syntax} {go_gctx : GoGlobalContext} : go.type := go.Named "github.com/goose-lang/goose/testdata/examples/interfacerecursion.B"%go [].
 
+#[global] Opaque B.
+
 Definition c {ext : ffi_syntax} {go_gctx : GoGlobalContext} : go.type := go.Named "github.com/goose-lang/goose/testdata/examples/interfacerecursion.c"%go [].
 
+#[global] Opaque c.
+
 (* go: x.go:14:13 *)
 Definition c__Fooⁱᵐᵖˡ {ext : ffi_syntax} {go_gctx : GoGlobalContext} : val :=
   λ: "c" <>,

diff --git a/testdata/examples/logging2/logging2.gold.v b/testdata/examples/logging2/logging2.gold.v
@@ -13,8 +13,12 @@ Module logging2.
 
 Definition Log {ext : ffi_syntax} {go_gctx : GoGlobalContext} : go.type := go.Named "github.com/goose-lang/goose/testdata/examples/logging2.Log"%go [].
 
+#[global] Opaque Log.
+
 Definition Txn {ext : ffi_syntax} {go_gctx : GoGlobalContext} : go.type := go.Named "github.com/goose-lang/goose/testdata/examples/logging2.Txn"%go [].
 
+#[global] Opaque Txn.
+
 Definition LOGCOMMIT {ext : ffi_syntax} {go_gctx : GoGlobalContext} : val := #(W64 0).
 
 Definition LOGSTART {ext : ffi_syntax} {go_gctx : GoGlobalContext} : val := #(W64 1).

diff --git a/testdata/examples/mapliteral/mapliteral.gold.v b/testdata/examples/mapliteral/mapliteral.gold.v
@@ -9,6 +9,8 @@ Module example.
 
 Definition Nested {ext : ffi_syntax} {go_gctx : GoGlobalContext} : go.type := go.Named "github.com/goose-lang/goose/testdata/examples/mapliteral.Nested"%go [].
 
+#[global] Opaque Nested.
+
 Definition f {ext : ffi_syntax} {go_gctx : GoGlobalContext} : go_string := "github.com/goose-lang/goose/testdata/examples/mapliteral.f"%go.
 
 Definition mapliteral {ext : ffi_syntax} {go_gctx : GoGlobalContext} : go_string := "github.com/goose-lang/goose/testdata/examples/mapliteral.mapliteral"%go.

diff --git a/testdata/examples/semantics/semantics.gold.v b/testdata/examples/semantics/semantics.gold.v
@@ -14,76 +14,148 @@ Module semantics.
 
 Definition unit {ext : ffi_syntax} {go_gctx : GoGlobalContext} : go.type := go.Named "github.com/goose-lang/goose/testdata/examples/semantics.unit"%go [].
 
+#[global] Opaque unit.
+
 Definition Editor {ext : ffi_syntax} {go_gctx : GoGlobalContext} : go.type := go.Named "github.com/goose-lang/goose/testdata/examples/semantics.Editor"%go [].
 
+#[global] Opaque Editor.
+
 Definition Pair {ext : ffi_syntax} {go_gctx : GoGlobalContext} : go.type := go.Named "github.com/goose-lang/goose/testdata/examples/semantics.Pair"%go [].
 
+#[global] Opaque Pair.
+
 Definition Uint32 {ext : ffi_syntax} {go_gctx : GoGlobalContext} : go.type := go.Named "github.com/goose-lang/goose/testdata/examples/semantics.Uint32"%go [].
 
+#[global] Opaque Uint32.
+
 Definition geometryInterface {ext : ffi_syntax} {go_gctx : GoGlobalContext} : go.type := go.Named "github.com/goose-lang/goose/testdata/examples/semantics.geometryInterface"%go [].
 
+#[global] Opaque geometryInterface.
+
 Definition SquareStruct {ext : ffi_syntax} {go_gctx : GoGlobalContext} : go.type := go.Named "github.com/goose-lang/goose/testdata/examples/semantics.SquareStruct"%go [].
 
+#[global] Opaque SquareStruct.
+
 Definition NumStruct {ext : ffi_syntax} {go_gctx : GoGlobalContext} : go.type := go.Named "github.com/goose-lang/goose/testdata/examples/semantics.NumStruct"%go [].
 
+#[global] Opaque NumStruct.
+
 Definition shapeInterface {ext : ffi_syntax} {go_gctx : GoGlobalContext} : go.type := go.Named "github.com/goose-lang/goose/testdata/examples/semantics.shapeInterface"%go [].
 
+#[global] Opaque shapeInterface.
+
 Definition polygonInterface {ext : ffi_syntax} {go_gctx : GoGlobalContext} : go.type := go.Named "github.com/goose-lang/goose/testdata/examples/semantics.polygonInterface"%go [].
 
+#[global] Opaque polygonInterface.
+
 Definition shapeStruct {ext : ffi_syntax} {go_gctx : GoGlobalContext} : go.type := go.Named "github.com/goose-lang/goose/testdata/examples/semantics.shapeStruct"%go [].
 
+#[global] Opaque shapeStruct.
+
 Definition polygonStruct {ext : ffi_syntax} {go_gctx : GoGlobalContext} : go.type := go.Named "github.com/goose-lang/goose/testdata/examples/semantics.polygonStruct"%go [].
 
+#[global] Opaque polygonStruct.
+
 Definition dogInterface {ext : ffi_syntax} {go_gctx : GoGlobalContext} : go.type := go.Named "github.com/goose-lang/goose/testdata/examples/semantics.dogInterface"%go [].
 
+#[global] Opaque dogInterface.
+
 Definition catInterface {ext : ffi_syntax} {go_gctx : GoGlobalContext} : go.type := go.Named "github.com/goose-lang/goose/testdata/examples/semantics.catInterface"%go [].
 
+#[global] Opaque catInterface.
+
 Definition Puppy {ext : ffi_syntax} {go_gctx : GoGlobalContext} : go.type := go.Named "github.com/goose-lang/goose/testdata/examples/semantics.Puppy"%go [].
 
+#[global] Opaque Puppy.
+
 Definition Kitten {ext : ffi_syntax} {go_gctx : GoGlobalContext} : go.type := go.Named "github.com/goose-lang/goose/testdata/examples/semantics.Kitten"%go [].
 
+#[global] Opaque Kitten.
+
 Definition printInterface {ext : ffi_syntax} {go_gctx : GoGlobalContext} : go.type := go.Named "github.com/goose-lang/goose/testdata/examples/semantics.printInterface"%go [].
 
+#[global] Opaque printInterface.
+
 Definition PaperStruct {ext : ffi_syntax} {go_gctx : GoGlobalContext} : go.type := go.Named "github.com/goose-lang/goose/testdata/examples/semantics.PaperStruct"%go [].
 
+#[global] Opaque PaperStruct.
+
 Definition Flower {ext : ffi_syntax} {go_gctx : GoGlobalContext} : go.type := go.Named "github.com/goose-lang/goose/testdata/examples/semantics.Flower"%go [].
 
+#[global] Opaque Flower.
+
 Definition Flora {ext : ffi_syntax} {go_gctx : GoGlobalContext} : go.type := go.Named "github.com/goose-lang/goose/testdata/examples/semantics.Flora"%go [].
 
+#[global] Opaque Flora.
+
 Definition Lily {ext : ffi_syntax} {go_gctx : GoGlobalContext} : go.type := go.Named "github.com/goose-lang/goose/testdata/examples/semantics.Lily"%go [].
 
+#[global] Opaque Lily.
+
 Definition Rose {ext : ffi_syntax} {go_gctx : GoGlobalContext} : go.type := go.Named "github.com/goose-lang/goose/testdata/examples/semantics.Rose"%go [].
 
+#[global] Opaque Rose.
+
 Definition Daisy {ext : ffi_syntax} {go_gctx : GoGlobalContext} : go.type := go.Named "github.com/goose-lang/goose/testdata/examples/semantics.Daisy"%go [].
 
+#[global] Opaque Daisy.
+
 Definition LoopStruct {ext : ffi_syntax} {go_gctx : GoGlobalContext} : go.type := go.Named "github.com/goose-lang/goose/testdata/examples/semantics.LoopStruct"%go [].
 
+#[global] Opaque LoopStruct.
+
 Definition BoolTest {ext : ffi_syntax} {go_gctx : GoGlobalContext} : go.type := go.Named "github.com/goose-lang/goose/testdata/examples/semantics.BoolTest"%go [].
 
+#[global] Opaque BoolTest.
+
 Definition ArrayEditor {ext : ffi_syntax} {go_gctx : GoGlobalContext} : go.type := go.Named "github.com/goose-lang/goose/testdata/examples/semantics.ArrayEditor"%go [].
 
+#[global] Opaque ArrayEditor.
+
 Definition Bar {ext : ffi_syntax} {go_gctx : GoGlobalContext} : go.type := go.Named "github.com/goose-lang/goose/testdata/examples/semantics.Bar"%go [].
 
+#[global] Opaque Bar.
+
 Definition Foo {ext : ffi_syntax} {go_gctx : GoGlobalContext} : go.type := go.Named "github.com/goose-lang/goose/testdata/examples/semantics.Foo"%go [].
 
+#[global] Opaque Foo.
+
 Definition TwoInts {ext : ffi_syntax} {go_gctx : GoGlobalContext} : go.type := go.Named "github.com/goose-lang/goose/testdata/examples/semantics.TwoInts"%go [].
 
+#[global] Opaque TwoInts.
+
 Definition S {ext : ffi_syntax} {go_gctx : GoGlobalContext} : go.type := go.Named "github.com/goose-lang/goose/testdata/examples/semantics.S"%go [].
 
+#[global] Opaque S.
+
 Definition StructWrap {ext : ffi_syntax} {go_gctx : GoGlobalContext} : go.type := go.Named "github.com/goose-lang/goose/testdata/examples/semantics.StructWrap"%go [].
 
+#[global] Opaque StructWrap.
+
 Definition StructWithFunc {ext : ffi_syntax} {go_gctx : GoGlobalContext} : go.type := go.Named "github.com/goose-lang/goose/testdata/examples/semantics.StructWithFunc"%go [].
 
+#[global] Opaque StructWithFunc.
+
 Definition switchConcrete {ext : ffi_syntax} {go_gctx : GoGlobalContext} : go.type := go.Named "github.com/goose-lang/goose/testdata/examples/semantics.switchConcrete"%go [].
 
+#[global] Opaque switchConcrete.
+
 Definition switchInterface {ext : ffi_syntax} {go_gctx : GoGlobalContext} : go.type := go.Named "github.com/goose-lang/goose/testdata/examples/semantics.switchInterface"%go [].
 
+#[global] Opaque switchInterface.
+
 Definition DefinedStr {ext : ffi_syntax} {go_gctx : GoGlobalContext} : go.type := go.Named "github.com/goose-lang/goose/testdata/examples/semantics.DefinedStr"%go [].
 
+#[global] Opaque DefinedStr.
+
 Definition List {ext : ffi_syntax} {go_gctx : GoGlobalContext} (T : go.type) : go.type := go.Named "github.com/goose-lang/goose/testdata/examples/semantics.List"%go [T].
 
+#[global] Opaque List.
+
 Definition Log {ext : ffi_syntax} {go_gctx : GoGlobalContext} : go.type := go.Named "github.com/goose-lang/goose/testdata/examples/semantics.Log"%go [].
 
+#[global] Opaque Log.
+
 Definition AdderType {ext : ffi_syntax} {go_gctx : GoGlobalContext} : go.type := go.FunctionType (go.Signature [go.uint64] false [go.uint64]).
 
 Definition MultipleArgsType {ext : ffi_syntax} {go_gctx : GoGlobalContext} : go.type := go.FunctionType (go.Signature [go.uint64; go.bool] false [go.uint64]).

diff --git a/testdata/examples/simpledb/simpledb.gold.v b/testdata/examples/simpledb/simpledb.gold.v
@@ -13,16 +13,28 @@ Module simpledb.
 
 Definition Table {ext : ffi_syntax} {go_gctx : GoGlobalContext} : go.type := go.Named "github.com/goose-lang/goose/testdata/examples/simpledb.Table"%go [].
 
+#[global] Opaque Table.
+
 Definition Entry {ext : ffi_syntax} {go_gctx : GoGlobalContext} : go.type := go.Named "github.com/goose-lang/goose/testdata/examples/simpledb.Entry"%go [].
 
+#[global] Opaque Entry.
+
 Definition lazyFileBuf {ext : ffi_syntax} {go_gctx : GoGlobalContext} : go.type := go.Named "github.com/goose-lang/goose/testdata/examples/simpledb.lazyFileBuf"%go [].
 
+#[global] Opaque lazyFileBuf.
+
 Definition bufFile {ext : ffi_syntax} {go_gctx : GoGlobalContext} : go.type := go.Named "github.com/goose-lang/goose/testdata/examples/simpledb.bufFile"%go [].
 
+#[global] Opaque bufFile.
+
 Definition tableWriter {ext : ffi_syntax} {go_gctx : GoGlobalContext} : go.type := go.Named "github.com/goose-lang/goose/testdata/examples/simpledb.tableWriter"%go [].
 
+#[global] Opaque tableWriter.
+
 Definition Database {ext : ffi_syntax} {go_gctx : GoGlobalContext} : go.type := go.Named "github.com/goose-lang/goose/testdata/examples/simpledb.Database"%go [].
 
+#[global] Opaque Database.
+
 Definition UseMarshal {ext : ffi_syntax} {go_gctx : GoGlobalContext} : go_string := "github.com/goose-lang/goose/testdata/examples/simpledb.UseMarshal"%go.
 
 Definition CreateTable {ext : ffi_syntax} {go_gctx : GoGlobalContext} : go_string := "github.com/goose-lang/goose/testdata/examples/simpledb.CreateTable"%go.

diff --git a/testdata/examples/unittest/generics/generics.gold.v b/testdata/examples/unittest/generics/generics.gold.v
@@ -10,14 +10,24 @@ Module generics.
 
 Definition Box {ext : ffi_syntax} {go_gctx : GoGlobalContext} (T : go.type) : go.type := go.Named "github.com/goose-lang/goose/testdata/examples/unittest/generics.Box"%go [T].
 
+#[global] Opaque Box.
+
 Definition Container {ext : ffi_syntax} {go_gctx : GoGlobalContext} (T : go.type) : go.type := go.Named "github.com/goose-lang/goose/testdata/examples/unittest/generics.Container"%go [T].
 
+#[global] Opaque Container.
+
 Definition UseContainer {ext : ffi_syntax} {go_gctx : GoGlobalContext} : go.type := go.Named "github.com/goose-lang/goose/testdata/examples/unittest/generics.UseContainer"%go [].
 
+#[global] Opaque UseContainer.
+
 Definition OnlyIndirect {ext : ffi_syntax} {go_gctx : GoGlobalContext} (T : go.type) : go.type := go.Named "github.com/goose-lang/goose/testdata/examples/unittest/generics.OnlyIndirect"%go [T].
 
+#[global] Opaque OnlyIndirect.
+
 Definition MultiParam {ext : ffi_syntax} {go_gctx : GoGlobalContext} (A : go.type) (B : go.type) : go.type := go.Named "github.com/goose-lang/goose/testdata/examples/unittest/generics.MultiParam"%go [A; B].
 
+#[global] Opaque MultiParam.
+
 Definition UnderlyingSlice {ext : ffi_syntax} {go_gctx : GoGlobalContext} : go_string := "github.com/goose-lang/goose/testdata/examples/unittest/generics.UnderlyingSlice"%go.
 
 Definition Clone {ext : ffi_syntax} {go_gctx : GoGlobalContext} : go_string := "github.com/goose-lang/goose/testdata/examples/unittest/generics.Clone"%go.
-Original file line number
+Diff line change
@@ -1,4 +1,4 @@
-    go 1.25.4
+    go 1.26
     use (
     	.
@@ Expand Down @@