Find index of nth occurrence of a character. Returns -1 if not found.

Find all indices where a character appears. Returns empty list if not found.

Find starting index of nth occurrence of a substring. Returns -1 if not found.

Find all starting indices where a substring appears (includes overlaps).

Split text at exact index positions. Indices auto-sorted and deduplicated.

Insert text at index position without replacing. Supports negative indices.

Delete characters in range [start, end).

Replace characters in range [start, end) with new text.

Find all regex matches with positions. Returns list of {start, end, match} dicts.

Extract content between markers with positions. Returns dict with content and position info.

Count character statistics. Returns dict with total, without_spaces, letters, digits, spaces, special.

Extract substrings by index ranges. Supports negative indices and omitting end. Returns list of {start, end, substring, length} dicts.