Added a log builtin

cmd/cmsh/main.go

@@ -20,6 +20,8 @@ func main() {
 	instRepl := repl.New(
 		ucl.WithModule(builtins.OS()),
 		ucl.WithModule(builtins.FS(nil)),
+		ucl.WithModule(builtins.Log(nil)),
+		ucl.WithModule(builtins.Strs()),
 	)
 	ctx := context.Background()
 

cmd/playwasm/jsiter.go

@@ -8,6 +8,7 @@ import (
 	"github.com/alecthomas/participle/v2"
 	"strings"
 	"syscall/js"
+	"ucl.lmika.dev/repl"
 	"ucl.lmika.dev/ucl"
 )
 
@@ -20,9 +21,12 @@ func invokeUCLCallback(name string, args ...any) {
 func initJS(ctx context.Context) {
 	uclObj := make(map[string]any)
 
-	inst := ucl.New(ucl.WithOut(ucl.LineHandler(func(line string) {
-		invokeUCLCallback("onOutLine", line)
-	})))
+	replInst := repl.New(
+		ucl.WithModule(builtins.Log(nil)),
+		ucl.WithModule(builtins.Strs()),
+		ucl.WithOut(ucl.LineHandler(func(line string) {
+			invokeUCLCallback("onOutLine", line)
+		})))
 
 	uclObj["eval"] = js.FuncOf(func(this js.Value, args []js.Value) any {
 		if len(args) != 2 {
@@ -36,7 +40,7 @@ func initJS(ctx context.Context) {
 		}
 
 		wantContinue := args[1].Bool()
-		if err := ucl.EvalAndDisplay(ctx, inst, cmdLine); err != nil {
+		if err := replInst.EvalAndDisplay(ctx, cmdLine); err != nil {
 			var p participle.Error
 			if errors.As(err, &p) && wantContinue {
 				invokeUCLCallback("onContinue")
@@ -50,21 +54,3 @@ func initJS(ctx context.Context) {
 	})
 	js.Global().Set("ucl", uclObj)
 }
-
-//
-//type uclOut struct {
-//	lineBuffer *bytes.Buffer
-//	writeLine  func(line string)
-//}
-//
-//func (uo *uclOut) Write(p []byte) (n int, err error) {
-//	for _, b := range p {
-//		if b == '\n' {
-//			uo.writeLine(uo.lineBuffer.String())
-//			uo.lineBuffer.Reset()
-//		} else {
-//			uo.lineBuffer.WriteByte(b)
-//		}
-//	}
-//	return len(p), nil
-//}

ucl/builtins/log.go

@@ -0,0 +1,44 @@
+package builtins
+
+import (
+	"context"
+	"log"
+	"strings"
+	"ucl.lmika.dev/ucl"
+)
+
+type LogMessageHandler func(s string) error
+
+func Log(handler LogMessageHandler) ucl.Module {
+	if handler == nil {
+		handler = func(s string) error {
+			log.Println(s)
+			return nil
+		}
+	}
+
+	lh := logHandler{handler: handler}
+
+	return ucl.Module{
+		Name: "log",
+		Builtins: map[string]ucl.BuiltinHandler{
+			"puts": lh.logMessage,
+		},
+	}
+}
+
+type logHandler struct {
+	handler LogMessageHandler
+}
+
+func (lh logHandler) logMessage(ctx context.Context, args ucl.CallArgs) (any, error) {
+	var sb strings.Builder
+	var s ucl.Object
+
+	for args.NArgs() > 0 {
+		if err := args.Bind(&s); err == nil {
+			sb.WriteString(s.String())
+		}
+	}
+	return nil, lh.handler(sb.String())
+}

ucl/builtins/log_test.go

@@ -0,0 +1,47 @@
+package builtins_test
+
+import (
+	"bytes"
+	"context"
+	"github.com/stretchr/testify/assert"
+	"testing"
+	"ucl.lmika.dev/ucl"
+	"ucl.lmika.dev/ucl/builtins"
+)
+
+func TestLog_Puts(t *testing.T) {
+	tests := []struct {
+		desc    string
+		eval    string
+		want    any
+		wantErr bool
+		wantLog string
+	}{
+		{desc: "log 1", eval: `log:puts "bad stuff here"`, wantLog: "bad stuff here\n"},
+		{desc: "log 2", eval: `log:puts "bad " 123 " here " [1 2 3]`, wantLog: "bad 123 here [1 2 3]\n"},
+		{desc: "log 3", eval: `log:puts`, wantLog: "\n"},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.desc, func(t *testing.T) {
+			var logMessage bytes.Buffer
+
+			inst := ucl.New(
+				ucl.WithModule(builtins.Log(func(s string) error {
+					logMessage.WriteString(s)
+					logMessage.WriteByte('\n')
+					return nil
+				})),
+			)
+
+			res, err := inst.Eval(context.Background(), tt.eval)
+			if tt.wantErr {
+				assert.Error(t, err)
+			} else {
+				assert.NoError(t, err)
+				assert.Equal(t, tt.want, res)
+			}
+			assert.Equal(t, tt.wantLog, logMessage.String())
+		})
+	}
+}

ucl/userbuiltin.go

@@ -94,20 +94,44 @@ func (u userBuiltin) invoke(ctx context.Context, args invocationArgs) (object, e
 
 func bindArg(v interface{}, arg object) error {
 	switch t := v.(type) {
+	case *Object:
+		*t = arg
+		return nil
 	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 *Listable:
+		i, ok := arg.(Listable)
+		if !ok {
+			return errors.New("exepected listable")
+		}
+		*t = i
+		return nil
 	case *string:
 		if arg != nil {
 			*t = arg.String()
 		} else {
 			*t = ""
 		}
+		return nil
 	case *int:
 		if iArg, ok := arg.(intObject); ok {
 			*t = int(iArg)
 		} else {
 			return errors.New("invalid arg")
 		}
+		return nil
 	}
 
 	switch t := arg.(type) {
@@ -198,3 +222,45 @@ 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) IsNil() bool {
+	return i.inv == nil
+}
+
+func (i Invokable) Invoke(ctx context.Context, args ...any) (any, error) {
+	if i.inv == nil {
+		return nil, nil
+	}
+
+	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
+}