From 66e274e971349e1b3adb2b961e58c6f08c144c5a Mon Sep 17 00:00:00 2001
From: guregu <greg@toki.waseda.jp>
Date: Thu, 14 Nov 2024 23:04:35 +0900
Subject: [PATCH] get_error if we need it later

---
 trealla/prolog.go     | 10 +++++-----
 trealla/query.go      | 30 ++++++++++++++++++++++++++++++
 trealla/query_test.go | 18 ++++++++++++++++++
 3 files changed, 53 insertions(+), 5 deletions(-)

diff --git a/trealla/prolog.go b/trealla/prolog.go
index 8fce3ed..70f031e 100644
--- a/trealla/prolog.go
+++ b/trealla/prolog.go
@@ -65,7 +65,7 @@ type prolog struct {
 	pl_query         wasmFunc
 	pl_redo          wasmFunc
 	pl_done          wasmFunc
-	pl_error         wasmFunc
+	// get_error        wasmFunc
 
 	procs map[string]Predicate
 	coros map[int64]coroutine
@@ -194,10 +194,10 @@ func (pl *prolog) init(parent *prolog) error {
 		return err
 	}
 
-	pl.pl_error, err = pl.function("pl_error")
-	if err != nil {
-		return err
-	}
+	// pl.get_error, err = pl.function("get_error")
+	// if err != nil {
+	// 	return err
+	// }
 
 	pl.pl_consult, err = pl.function("pl_consult")
 	if err != nil {
diff --git a/trealla/query.go b/trealla/query.go
index c24b0be..ecea5ec 100644
--- a/trealla/query.go
+++ b/trealla/query.go
@@ -321,6 +321,18 @@ func (q *query) redo(ctx context.Context) bool {
 			return false
 		}
 
+		// var erroring bool
+		// var errcode uint64
+		// {
+		// 	retv, err2 := pl.get_error.Call(ctx, uint64(pl.ptr))
+		// 	if err2 != nil {
+		// 		q.setError(fmt.Errorf("trealla: get_error internal error: %w", err))
+		// 		return false
+		// 	}
+		// 	errcode = retv[0]
+		// 	erroring = errcode != 0
+		// }
+
 		if q.done {
 			delete(pl.running, q.subquery)
 			// defer q.close()
@@ -339,6 +351,24 @@ func (q *query) redo(ctx context.Context) bool {
 		stderr := q.stderr.String()
 		q.resetOutput()
 
+		// if erroring {
+		// 	var msg string
+		// 	if either := cmp.Or(stdout, stderr); either != "" {
+		// 		either = strings.TrimPrefix(either, "\x02")
+		// 		if strings.HasPrefix(either, "Error:") || strings.HasPrefix(either, "Warning:") {
+		// 			nl := strings.IndexByte(either, '\n')
+		// 			if nl > 0 {
+		// 				msg = either[:nl]
+		// 			}
+		// 		}
+		// 	}
+		// 	if msg == "" {
+		// 		msg = fmt.Sprintf("interpreter returned error code %d", errcode)
+		// 	}
+		// 	q.setError(fmt.Errorf("%s", msg))
+		// 	return false
+		// }
+
 		ans, err := pl.parse(q.goal, stdout, stderr)
 		switch {
 		case IsFailure(err):
diff --git a/trealla/query_test.go b/trealla/query_test.go
index 2d4f624..3dd8d6a 100644
--- a/trealla/query_test.go
+++ b/trealla/query_test.go
@@ -311,6 +311,24 @@ func TestThrow(t *testing.T) {
 	}
 }
 
+// func TestInterpError(t *testing.T) {
+// 	pl, err := trealla.New()
+// 	if err != nil {
+// 		t.Fatal(err)
+// 	}
+
+// 	ctx := context.Background()
+// 	q := pl.Query(ctx, `abort.`)
+// 	if q.Next(ctx) {
+// 		t.Error("unexpected result", q.Current())
+// 	}
+// 	err = q.Err()
+// 	t.Fatal(err)
+// 	if err == nil {
+// 		t.Fatal("expected error")
+// 	}
+// }
+
 func TestPreopen(t *testing.T) {
 	if runtime.GOOS == "windows" {
 		t.Skip("skipping unixy test")