implement generic code lens interface

decoder/code_lens.go

@@ -0,0 +1,25 @@
+package decoder
+
+import (
+	"context"
+
+	"github.com/hashicorp/hcl-lang/lang"
+)
+
+func (d *PathDecoder) CodeLensesForFile(ctx context.Context, file string) ([]lang.CodeLens, error) {
+	lenses := make([]lang.CodeLens, 0)
+
+	// TODO: multierror
+
+	for _, clFunc := range d.decoderCtx.CodeLenses {
+		ctx = withPathContext(ctx, d.pathCtx)
+
+		cls, err := clFunc(ctx, d.path, file)
+		if err != nil {
+			return lenses, err
+		}
+		lenses = append(lenses, cls...)
+	}
+
+	return lenses, nil
+}

decoder/context.go

@@ -1,5 +1,7 @@
 package decoder
 
+import "github.com/hashicorp/hcl-lang/lang"
+
 type DecoderContext struct {
 	// UTM parameters for docs URLs
 	// utm_source parameter, typically language server identification
@@ -8,6 +10,8 @@ type DecoderContext struct {
 	UtmMedium string
 	// utm_content parameter, e.g. documentHover or documentLink
 	UseUtmContent bool
+
+	CodeLenses []lang.CodeLensFunc
 }
 
 func (d *Decoder) SetContext(ctx DecoderContext) {

decoder/path_context.go

@@ -1,6 +1,9 @@
 package decoder
 
 import (
+	"context"
+	"fmt"
+
 	"github.com/hashicorp/hcl-lang/reference"
 	"github.com/hashicorp/hcl-lang/schema"
 	"github.com/hashicorp/hcl/v2"
@@ -12,3 +15,17 @@ type PathContext struct {
 	ReferenceTargets reference.Targets
 	Files            map[string]*hcl.File
 }
+
+type pathCtxKey struct{}
+
+func withPathContext(ctx context.Context, pathCtx *PathContext) context.Context {
+	return context.WithValue(ctx, pathCtxKey{}, pathCtx)
+}
+
+func PathCtx(ctx context.Context) (*PathContext, error) {
+	pathCtx, ok := ctx.Value(pathCtxKey{}).(*PathContext)
+	if !ok {
+		return nil, fmt.Errorf("path context not found")
+	}
+	return pathCtx, nil
+}

lang/code_lens.go

@@ -0,0 +1,24 @@
+package lang
+
+import (
+	"context"
+
+	"github.com/hashicorp/hcl/v2"
+)
+
+type CodeLensFunc func(ctx context.Context, path Path, file string) ([]CodeLens, error)
+
+type CodeLens struct {
+	Range   hcl.Range
+	Command Command
+}
+
+type Command struct {
+	Title     string
+	ID        string
+	Arguments []CommandArgument
+}
+
+type CommandArgument interface {
+	MarshalJSON() ([]byte, error)
+}