Statifier.Validator.Checks.Cancel (Statifier v2.0.0)

Spec 6.3.1's single constraint on <cancel>: "A conformant SCXML document MUST specify exactly one of sendid or sendidexpr." Reports {:cancel_sendid_and_sendidexpr} when both are present and {:cancel_no_sendid} when neither is, both at the <cancel> element's own location.

lib/statifier/document/cancel.ex makes both sendid and sendidexpr simultaneously representable, and both absent representable too, precisely so this check can report the shape rather than lowering refusing to build it - the same division of labour Checks.Send has for its own mutually exclusive pairs. <cancel> gets its own file per the house pattern (Checks.Invoke, Checks.Assign, Checks.Param): one constraint is enough to justify one file at this repo's granularity.

The walk reaches every block a <cancel> can appear in: a state's onentry/onexit, its own (and its <initial> element's) transitions, <if>/<foreach> bodies nested in any of those, and every <invoke>'s <finalize> block - the same reach Checks.Send needs, since both elements are executable content that can occur wherever the other can.

Summary

Functions

check(document, context)

Walks every <cancel> in the document and returns a :cancel_sendid_and_sendidexpr or :cancel_no_sendid error for each one whose sendid/sendidexpr attributes violate 6.3.1's exactly-one rule. Returns [] when every <cancel> in the document specifies exactly one.

Functions

check(document, context)

@spec check(
  document :: Statifier.Document.t(),
  context :: Statifier.Validator.Context.t()
) :: [
  Statifier.Validator.Error.t()
]