Fixes (part 3) (#152)

Following on from #148 and #149, this PR contains various minor fixes:
* slices can now be used with generics
* struct tags are now supported
* lint warnings have been fixed

compiler/coroutine_test.go

@@ -294,6 +294,18 @@ func TestCoroutineYield(t *testing.T) {
 			coro:   func() { GenericStructClosure(3) },
 			yields: []int{3, 5, 7},
 		},
+
+		{
+			name:   "JSON roundtrip",
+			coro:   func() { JSONRoundTrip(3) },
+			yields: []int{3, 3},
+		},
+
+		{
+			name:   "generics with slices",
+			coro:   func() { GenericSlice(3) },
+			yields: []int{0, 1, 2, 0, 1, 2},
+		},
 	}
 
 	// This emulates the installation of function type information by the

compiler/function.go

@@ -558,6 +558,10 @@ func (g *genericInstance) gcshapePath() string {
 func writeGoShape(b *strings.Builder, tt types.Type) {
 	b.WriteString("go.shape.")
 
+	writeGoShapeType(b, tt)
+}
+
+func writeGoShapeType(b *strings.Builder, tt types.Type) {
 	switch t := tt.Underlying().(type) {
 	case *types.Basic:
 		b.WriteString(t.Name())
@@ -588,6 +592,9 @@ func writeGoShape(b *strings.Builder, tt types.Type) {
 			b.WriteString(f.Type().String())
 		}
 		b.WriteString(" }")
+	case *types.Slice:
+		b.WriteString("[]")
+		writeGoShapeType(b, t.Elem())
 	default:
 		panic(fmt.Sprintf("not implemented: %#v (%T)", tt, t))
 	}

compiler/testdata/coroutine.go

@@ -3,6 +3,8 @@
 package testdata
 
 import (
+	"encoding/json"
+	"fmt"
 	"math"
 	"reflect"
 	"time"
@@ -777,3 +779,54 @@ type GenericAdder[A adder] struct{ adder A }
 func (b *GenericAdder[A]) Add(n int) int {
 	return b.adder.Add(n)
 }
+
+func JSONRoundTrip(n int) {
+	b, err := json.Marshal(struct {
+		N int `json:"n"`
+	}{n})
+	if err != nil {
+		panic(err)
+	}
+	if string(b) != fmt.Sprintf(`{"n":%d}`, n) {
+		panic(fmt.Errorf("unexpected JSON: %v", b))
+	}
+
+	coroutine.Yield[int, any](n)
+
+	var result struct {
+		N int `json:"n"`
+	}
+	if err := json.Unmarshal(b, &result); err != nil {
+		panic(err)
+	}
+	coroutine.Yield[int, any](result.N)
+}
+
+type Cloner[S ~[]E, E any] struct {
+	Slice S
+}
+
+func (c *Cloner[S, E]) Clone() S {
+	s2 := make(S, len(c.Slice))
+	copy(s2, c.Slice)
+	return s2
+}
+
+func GenericSlice(n int) {
+	ints := make([]int, n)
+	for i := range ints {
+		ints[i] = i
+	}
+	for _, x := range ints {
+		coroutine.Yield[int, any](x)
+	}
+
+	cloner := &Cloner[[]int, int]{Slice: ints}
+	ints2 := cloner.Clone()
+
+	clear(ints)
+
+	for _, x := range ints2 {
+		coroutine.Yield[int, any](x)
+	}
+}