993 B
Explanation model
The community provider converts regexpp nodes into a stable application AST inside the syntax worker. Nodes carry deterministic IDs, UTF-16 ranges, raw source, capture metadata, quantifier bounds, assertion kind, support status, provider identity and provenance.
Explanations are original deterministic text selected by node type. Nullable and minimum/maximum consumed-length properties are derived recursively where the normalized node semantics support them. Backreference lengths and exact bounds for Unicode properties of strings remain unknown rather than being guessed.
regexpp 4.12.2 does not expose tolerant recovery. A malformed pattern therefore gets the provider's exact diagnostic plus an application-owned error node. No partial regexpp AST is claimed.
The explanation tree is structural. It is never called an actual execution trace. Selecting a node selects and scrolls its exact editor range; selecting pattern text chooses the smallest enclosing node.