6. Slab Allocation for Nodes, Child Lists and Frames (5D03bf2)

• Nodes, child slices and capture frames come from per-parser chunks, in the spirit of an arena: a chunk stays alive while any of its nodes is referenced (the lifetime of the parse result). Repetition children are gathered on a shared stack and copied out once. Memo entries were packed into 128 bytes.
• Effect: allocations per parse dropped by about three quarters (JSON 940 k → 250 k); time −5 to −10%.