Added bindable invokables

ucl/userbuiltin.go

@@ -4,6 +4,8 @@ import (
 	"context"
 	"errors"
 	"reflect"
+
+	"github.com/lmika/gopkgs/fp/slices"
 )
 
 type BuiltinHandler func(ctx context.Context, args CallArgs) (any, error)
@@ -24,7 +26,7 @@ func (ca *CallArgs) Bind(vars ...interface{}) error {
 	}
 
 	for i, v := range vars {
-		if err := bindArg(v, ca.args.args[i]); err != nil {
+		if err := ca.bindArg(v, ca.args.args[i]); err != nil {
 			return err
 		}
 	}
@@ -72,7 +74,7 @@ func (ca CallArgs) BindSwitch(name string, val interface{}) error {
 		return nil
 	}
 
-	return bindArg(val, (*vars)[0])
+	return ca.bindArg(val, (*vars)[0])
 }
 
 func (inst *Inst) SetBuiltin(name string, fn BuiltinHandler) {
@@ -92,10 +94,22 @@ func (u userBuiltin) invoke(ctx context.Context, args invocationArgs) (object, e
 	return fromGoValue(v)
 }
 
-func bindArg(v interface{}, arg object) error {
+func (ca CallArgs) bindArg(v interface{}, arg object) error {
 	switch t := v.(type) {
 	case *interface{}:
 		*t, _ = toGoValue(arg)
+	case *Invokable:
+		i, ok := arg.(invokable)
+		if !ok {
+			return errors.New("exepected invokable")
+		}
+		*t = Invokable{
+			inv:  i,
+			eval: ca.args.eval,
+			inst: ca.args.inst,
+			ec:   ca.args.ec,
+		}
+		return nil
 	case *string:
 		*t = arg.String()
 	case *int:
@@ -194,3 +208,37 @@ func (m missingHandlerInvokable) invoke(ctx context.Context, args invocationArgs
 
 	return fromGoValue(v)
 }
+
+type Invokable struct {
+	inv  invokable
+	eval evaluator
+	inst *Inst
+	ec   *evalCtx
+}
+
+func (i Invokable) Invoke(ctx context.Context, args ...any) (any, error) {
+	var err error
+	invArgs := invocationArgs{
+		eval: i.eval,
+		ec:   i.ec,
+		inst: i.inst,
+	}
+
+	invArgs.args, err = slices.MapWithError(args, func(a any) (object, error) {
+		return fromGoValue(a)
+	})
+	if err != nil {
+		return nil, err
+	}
+
+	res, err := i.inv.invoke(ctx, invArgs)
+	if err != nil {
+		return nil, err
+	}
+
+	goRes, ok := toGoValue(res)
+	if !ok {
+		return nil, errors.New("cannot convert result to Go Value")
+	}
+	return goRes, err
+}

ucl/userbuiltin_test.go

@@ -6,6 +6,7 @@ import (
 	"fmt"
 	"strings"
 	"testing"
+
 	"ucl.lmika.dev/ucl"
 
 	"github.com/stretchr/testify/assert"
@@ -265,6 +266,30 @@ func TestCallArgs_CanBind(t *testing.T) {
 			assert.Equal(t, tt.want, res)
 		})
 	}
+
+	t.Run("can bind invokable", func(t *testing.T) {
+		inst := ucl.New()
+		inst.SetBuiltin("wrap", func(ctx context.Context, args ucl.CallArgs) (any, error) {
+			var inv ucl.Invokable
+
+			if err := args.Bind(&inv); err != nil {
+				return nil, err
+			}
+
+			res, err := inv.Invoke(ctx, "hello")
+			if err != nil {
+				return nil, err
+			}
+
+			return fmt.Sprintf("[[%v]]", res), nil
+		})
+
+		ctx := context.Background()
+
+		res, err := inst.Eval(ctx, `wrap { |x| toUpper $x }`)
+		assert.NoError(t, err)
+		assert.Equal(t, "[[HELLO]]", res)
+	})
 }
 
 func TestCallArgs_MissingCommandHandler(t *testing.T) {