Enum

insert-mode

Selects the behavior for an insert when the new key matches an existing key.

enum insert-mode {
  overwrite,
  add,
  append,
  prepend,
}

Cases

CaseDescription
overwriteUpdates the existing key's value by overwriting it with the new value.
addFails, leaving the existing key's value unmodified.
appendUpdates the existing key's value by appending the new value to it.
prependUpdates the existing key's value by prepending the new value to it.