Implement sequence splitting: split-at, split-with, partition-by, dedupe, keep-indexed

[andreasronge]

Context

Part of the Clojure core candidate implementation effort (Phase 2c). Natural companions to already-supported partition, partition-all, keep.

Functions to implement

Function	Description
split-at	Splits seq at index
split-with	Splits seq by predicate
partition-by	Partitions by change in function value
dedupe	Removes consecutive duplicates
keep-indexed	Keeps non-nil results with index

Notes

• These extend the existing partitioning/filtering capabilities
• All are pure sequence transformations

🤖 Generated with Claude Code

[andreasronge]

Implemented in 89d8fa9: split-at, split-with, partition-by, dedupe, keep-indexed with full normalization support and 26 integration tests.