v0.0.559 Add .Iterate and .IterateFunc methods to wmo

wmo/queryFind.go

@@ -7,9 +7,10 @@ import (
 	"go.mongodb.org/mongo-driver/mongo/options"
 	"gogs.mikescher.com/BlackForestBytes/goext/exerr"
 	"gogs.mikescher.com/BlackForestBytes/goext/langext"
+	"iter"
 )
 
-func (c *Coll[TData]) Find(ctx context.Context, filter bson.M, opts ...*options.FindOptions) ([]TData, error) {
+func (c *Coll[TData]) createFindQuery(ctx context.Context, filter bson.M, opts ...*options.FindOptions) (*mongo.Cursor, error) {
 
 	pipeline := mongo.Pipeline{}
 	pipeline = append(pipeline, bson.D{{Key: "$match", Value: filter}})
@@ -64,6 +65,16 @@ func (c *Coll[TData]) Find(ctx context.Context, filter bson.M, opts ...*options.
 		return nil, exerr.Wrap(err, "mongo-aggregation failed").Any("pipeline", pipeline).Str("collection", c.Name()).Build()
 	}
 
+	return cursor, nil
+}
+
+func (c *Coll[TData]) Find(ctx context.Context, filter bson.M, opts ...*options.FindOptions) ([]TData, error) {
+
+	cursor, err := c.createFindQuery(ctx, filter, opts...)
+	if err != nil {
+		return nil, exerr.Wrap(err, "").Build()
+	}
+
 	defer func() { _ = cursor.Close(ctx) }()
 
 	res, err := c.decodeAll(ctx, cursor)
@@ -74,6 +85,58 @@ func (c *Coll[TData]) Find(ctx context.Context, filter bson.M, opts ...*options.
 	return res, nil
 }
 
+func (c *Coll[TData]) IterateFunc(ctx context.Context, filter bson.M, fn func(v TData) error, opts ...*options.FindOptions) error {
+
+	cursor, err := c.createFindQuery(ctx, filter, opts...)
+	if err != nil {
+		return exerr.Wrap(err, "").Build()
+	}
+
+	defer func() { _ = cursor.Close(ctx) }()
+
+	for cursor.Next(ctx) {
+
+		v, err := c.decodeSingle(ctx, cursor)
+		if err != nil {
+			return exerr.Wrap(err, "").Build()
+		}
+
+		err = fn(v)
+		if err != nil {
+			return exerr.Wrap(err, "").Build()
+		}
+
+	}
+
+	return nil
+}
+
+func (c *Coll[TData]) Iterate(ctx context.Context, filter bson.M, opts ...*options.FindOptions) iter.Seq2[TData, error] {
+
+	cursor, err := c.createFindQuery(ctx, filter, opts...)
+	if err != nil {
+		return langext.IterSingleValueSeq2[TData, error](nil, exerr.Wrap(err, "").Build())
+	}
+
+	return func(yield func(TData, error) bool) {
+		defer func() { _ = cursor.Close(ctx) }()
+
+		for cursor.Next(ctx) {
+			v, err := c.decodeSingle(ctx, cursor)
+			if err != nil {
+				if !yield(nil, err) {
+					return
+				}
+				continue
+			}
+
+			if !yield(v, nil) {
+				return
+			}
+		}
+	}
+}
+
 // converts FindOptions to AggregateOptions
 func convertFindOpt(v *options.FindOptions) (*options.AggregateOptions, error) {
 	if v == nil {