chore: import upstream snapshot with attribution

components/document/parser/text_parser.go

@@ -0,0 +1,60 @@
+/*
+ * Copyright 2024 CloudWeGo Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package parser
+
+import (
+	"context"
+	"io"
+
+	"github.com/cloudwego/eino/schema"
+)
+
+const (
+	// MetaKeySource is the metadata key storing the document's source URI.
+	MetaKeySource = "_source"
+)
+
+// TextParser is a simple parser that reads the text from a reader and returns a single document.
+// eg:
+//
+//	docs, err := TextParser.Parse(ctx, strings.NewReader("hello world"))
+//	fmt.Println(docs[0].Content) // "hello world"
+type TextParser struct{}
+
+// Parse reads the text from a reader and returns a single document.
+func (dp TextParser) Parse(ctx context.Context, reader io.Reader, opts ...Option) ([]*schema.Document, error) {
+	data, err := io.ReadAll(reader)
+	if err != nil {
+		return nil, err
+	}
+
+	opt := GetCommonOptions(&Options{}, opts...)
+
+	meta := make(map[string]any)
+	meta[MetaKeySource] = opt.URI
+
+	for k, v := range opt.ExtraMeta {
+		meta[k] = v
+	}
+
+	doc := &schema.Document{
+		Content:  string(data),
+		MetaData: meta,
+	}
+
+	return []*schema.Document{doc}, nil
+}