package tezos-protocol-alpha

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This module provides an API for extracting tickets of arbitrary types from an OCaml values, given a type-witness.

type Tezos_protocol_environment_alpha.Error_monad.error +=
  1. | Forbidden_zero_ticket_quantity
type ex_ticket =
  1. | Ex_ticket : 'a Script_typed_ir.comparable_ty * 'a Script_typed_ir.ticket -> ex_ticket

A type for representing existentially quantified tickets (tickets with different types of payloads). An ex_ticket value consists of:

  • A type-witness representing the type of the content of the ticket.
  • A ticket value of the particular content type.
type 'a has_tickets

A type-witness that contains information about which branches of a type 'a include tickets. This value is used for traversing only the relevant branches of values when scanning for tickets.

type_has_tickets ctxt ty returns a has_tickets witness of the given shape ty.

val tickets_of_value : Alpha_context.context -> include_lazy:bool -> allow_zero_amount_tickets:bool -> 'a has_tickets -> 'a -> (ex_ticket list * Alpha_context.context) Tezos_protocol_environment_alpha.Error_monad.tzresult Tezos_protocol_environment_alpha.Lwt.t

tickets_of_value ctxt ~include_lazy ht value extracts all tickets from the given value, using the type-witness ht. The include_lazy flag determines whether or not to traverse lazy structures (values from the context). In case the include_lazy flag is true, any big-map contained in the value must have an empty overlay or else an error of type Unsupported_non_empty_overlay is returned. The reason for this restriction is that we assume that all lazy big-map diffs should be applied before calling this function. Dealing with non-empty overlays would be possible in theory, but practically difficult. The challenge is to distinguish between overlapping keys between the context and the overlay.

tickets_of_node ctxt ~include_lazy ht node extracts all tickets from the given node, using the type-witness ht.If ht indicates that values of the corresponding type may not contain tickets, the node value is not parsed. The include_lazy flag determines whether or not to traverse lazy structures (values from the context). In case the include_lazy flag is true, any big-map contained in the value must have an empty overlay or else an error of type Unsupported_non_empty_overlay is returned. The reason for this restriction is that we assume that all lazy big-map diffs should be applied before calling this function. Dealing with non-empty overlays would be possible in theory, but practically difficult. The challenge is to distinguish between overlapping keys between the context and the overlay.

val has_tickets : 'a has_tickets -> bool

has_tickets ht returns whether or not the type of the given has_tickets witness ht has tickets.