Structured representation of intended RDF graph changes.

A changeset declares changes through four actions:

• :add - insert new statements (no effect if already present)
• :update - add statements while removing existing values for the same subject/predicate combinations (property-level overwrite)
• :replace - add statements while removing all existing statements about the same subjects (subject-level overwrite)
• :remove - delete statements (no effect if not present)

Creating Changesets

Changesets can be created from keyword lists, maps, or RDF.Diff structs:

# From keyword list
Gno.Changeset.new(add: EX.S |> EX.p(EX.O))

# Multiple actions
Gno.Changeset.new(
  add: EX.S |> EX.p(EX.O1),
  replace: EX.S2 |> EX.p(EX.O2),
  remove: EX.S3 |> EX.p(EX.O3)
)

Before applying, a changeset is typically converted to a Gno.EffectiveChangeset that contains only the minimal changes needed against the current repository state. This happens automatically during Gno.commit/2.