Add fallback length-based splitting option for RecursiveCharacterTextSplitter when no separators found

[SandyKidYao]

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Feature request

Add a new parameter to the RecursiveCharacterTextSplitter class that ensures text splitting at the specified chunk size even when no separators are found in the input text. This would serve as a fallback mechanism when the regular separator-based splitting cannot be applied.

Motivation

Current Behavior:

• When the input text doesn't contain any characters specified in the separators parameter, the splitter returns the original text without performing any splitting.
• Attempting to use an empty string as a separator leads to undesired behavior: even when preferred separators are present in the text, the splitting still occurs at every character.

Limitations:

The current implementation works well for most common use cases but fails to handle edge cases where:

• Text lacks conventional separators but still needs to be split into smaller chunks
• Strict length limits need to be enforced regardless of separator presence

Use Case Benefits:

• This enhancement would provide more precise control over text chunk sizes
• It would ensure consistent behavior in edge cases where text structure differs from expectations
• Users would have more flexibility in handling various text formats and requirements
• The feature would maintain backward compatibility while adding more robust splitting capabilities
• This improvement would make the RecursiveCharacterTextSplitter more versatile and reliable across a broader range of use cases, particularly in scenarios where strict length control is crucial.

Proposal (If applicable)

No response