Chunking strategies

text = ("Our warranty lasts two years. It covers hardware faults. "
        "It does not cover water damage. To claim, email support with your order number. "
        "Claims are answered within five days.")
 
def fixed_chunks(text, size=60, overlap=15):
    """Cut every `size` characters; repeat `overlap` characters so ideas aren't cut in half."""
    step = size - overlap
    return [text[i:i + size] for i in range(0, len(text), step) if text[i:i + size].strip()]
 
def sentence_chunks(text, max_chars=90):
    """Pack whole sentences into chunks up to max_chars: never cuts a sentence."""
    chunks, cur = [], ""
    for s in [s.strip() + "." for s in text.split(".") if s.strip()]:
        if cur and len(cur) + len(s) + 1 > max_chars:
            chunks.append(cur); cur = s
        else:
            cur = f"{cur} {s}".strip()
    return chunks + [cur]
 
print("fixed-size with overlap:")
for c in fixed_chunks(text): print("  |", c)
print("sentence-aware:")
for c in sentence_chunks(text): print("  |", c)
 
# Parent-child: search small chunks, but hand the LLM the bigger parent around the match.
parents = sentence_chunks(text, max_chars=200)
children = [(pi, s) for pi, p in enumerate(parents) for s in sentence_chunks(p, max_chars=40)]
hit = next(pi for pi, s in children if "water" in s)      # pretend vector search matched this child
print("matched child ->", [s for pi, s in children if "water" in s][0])
print("parent sent  ->", parents[hit])

fixed-size with overlap:
  | Our warranty lasts two years. It covers hardware faults. It 
  | are faults. It does not cover water damage. To claim, email 
  | o claim, email support with your order number. Claims are an
  | . Claims are answered within five days.
sentence-aware:
  | Our warranty lasts two years. It covers hardware faults. It does not cover water damage.
  | To claim, email support with your order number. Claims are answered within five days.
matched child -> It does not cover water damage.
parent sent  -> Our warranty lasts two years. It covers hardware faults. It does not cover water damage. To claim, email support with your order number. Claims are answered within five days.