1 files changed, 88 insertions, 0 deletions
diff --git a/R2R/r2r/vecs/adapter/markdown.py b/R2R/r2r/vecs/adapter/markdown.py
new file mode 100755
index 00000000..149573f4
--- /dev/null
+++ b/R2R/r2r/vecs/adapter/markdown.py
@@ -0,0 +1,88 @@
+import re
+from typing import Any, Dict, Generator, Iterable, Optional, Tuple
+
+from flupy import flu
+
+from .base import AdapterContext, AdapterStep
+
+
+class MarkdownChunker(AdapterStep):
+    """
+    MarkdownChunker is an AdapterStep that splits a markdown string into chunks where a heading signifies the start of a chunk, and yields each chunk as a separate record.
+    """
+
+    def __init__(self, *, skip_during_query: bool):
+        """
+        Initializes the MarkdownChunker adapter.
+
+        Args:
+            skip_during_query (bool): Whether to skip chunking during querying.
+        """
+        self.skip_during_query = skip_during_query
+
+    @staticmethod
+    def split_by_heading(
+        md: str, max_tokens: int
+    ) -> Generator[str, None, None]:
+        regex_split = r"^(#{1,6}\s+.+)$"
+        headings = [
+            match.span()[0]
+            for match in re.finditer(regex_split, md, flags=re.MULTILINE)
+        ]
+
+        if headings == [] or headings[0] != 0:
+            headings.insert(0, 0)
+
+        sections = [md[i:j] for i, j in zip(headings, headings[1:] + [None])]
+
+        for section in sections:
+            chunks = flu(section.split(" ")).chunk(max_tokens)
+
+            is_not_useless_chunk = lambda i: not i in ["", "\n", []]
+
+            joined_chunks = filter(
+                is_not_useless_chunk, [" ".join(chunk) for chunk in chunks]
+            )
+
+            for joined_chunk in joined_chunks:
+                yield joined_chunk
+
+    def __call__(
+        self,
+        records: Iterable[Tuple[str, Any, Optional[Dict]]],
+        adapter_context: AdapterContext,
+        max_tokens: int = 99999999,
+    ) -> Generator[Tuple[str, Any, Dict], None, None]:
+        """
+        Splits each markdown string in the records into chunks where each heading starts a new chunk, and yields each chunk
+        as a separate record. If the `skip_during_query` attribute is set to True,
+        this step is skipped during querying.
+
+        Args:
+            records (Iterable[Tuple[str, Any, Optional[Dict]]]): Iterable of tuples each containing an id, a markdown string and an optional dict.
+            adapter_context (AdapterContext): Context of the adapter.
+            max_tokens (int): The maximum number of tokens per chunk
+
+        Yields:
+            Tuple[str, Any, Dict]: The id appended with chunk index, the chunk, and the metadata.
+        """
+        if max_tokens and max_tokens < 1:
+            raise ValueError("max_tokens must be a nonzero positive integer")
+
+        if (
+            adapter_context == AdapterContext("query")
+            and self.skip_during_query
+        ):
+            for id, markdown, metadata in records:
+                yield (id, markdown, metadata or {})
+        else:
+            for id, markdown, metadata in records:
+                headings = MarkdownChunker.split_by_heading(
+                    markdown, max_tokens
+                )
+                for heading_ix, heading in enumerate(headings):
+                    yield (
+                        f"{id}_head_{str(heading_ix).zfill(3)}",
+                        heading,
+                        metadata or {},
+                    )