Dmn.Compiler.Box (dmn v0.1.0)

The boxed expression that a part of a unit came from: what the source map (Dmn.Compiler.Source) knows of a range of the virtual source besides the element and the place in it.

Every node of the tree of a unit has a span, and the span is in a part of the source, so every node, whether it was parsed from a text or built from the syntax of a box, can be asked for its box (Dmn.Compiler.Source.box/2). A part that is in no box (the declaration of a variable, the wrapper of a unit) has none.

Field	Is
`kind`	`:literal_expression`, `:decision_table`, `:context`, `:function`, `:invocation`, `:relation`, `:list`, `:conditional`, `:filter`, `:for`, `:some` or `:every`
`id`, `label`, `line`	those of the box in the model (`nil` where the model has none)
`type_ref`	the type the box declares for its value
`boolean_part`	the part of the box that DMN 1.6 says MUST resolve to a boolean (10.2.1.8 to 10.2.1.10): `:if` of a conditional, `:match` of a filter, `:satisfies` of `some` and `every`, and `nil` for the others

boolean_part is what the specification asks of the box, and the compiler holds the box to it: the node a box makes is marked boxed: true (Dmn.Compiler.Tree.boxed/1), and a condition that is a value other than a boolean and null is null with an error for the whole node (D-212 of feel, as the TCK has it: 1150 #003, 1151 #004 and #005, 1153 #006). The source map says which box a part is in, and the flag in the node is what the passes of feel, which cannot ask the map, read.

Summary

Types

kind()

t()

Functions

of(expression)

The box of a boxed expression of the model, or nil for nil.

Types

kind()

@type kind() ::
  :literal_expression
  | :decision_table
  | :context
  | :function
  | :invocation
  | :relation
  | :list
  | :conditional
  | :filter
  | :for
  | :some
  | :every

t()

@type t() :: %Dmn.Compiler.Box{
  boolean_part: :if | :match | :satisfies | nil,
  id: String.t() | nil,
  kind: kind(),
  label: String.t() | nil,
  line: pos_integer() | nil,
  type_ref: String.t() | nil
}

Functions

of(expression)

@spec of(Dmn.Model.Expressions.t() | nil) :: t() | nil

The box of a boxed expression of the model, or nil for nil.

iex> box = Dmn.Compiler.Box.of(%Dmn.Model.Expressions.Iterator{kind: :some, id: "q1"})
iex> {box.kind, box.id, box.boolean_part}
{:some, "q1", :satisfies}