Evaluation context passed to constraint implementations.
The context carries metadata about the current evaluation environment, including backend capabilities and provenance tracking settings.
Threading
The Constraint.Context is constructed by Engine.Naive from the storage
backend's capabilities and passed through Evaluator → ConstraintEval
→ Constraint.evaluate/3. Constraint implementations receive it as the
third argument, enabling them to inspect storage capabilities if needed
(e.g., a future Z3 backend checking external_execution).
For v0.2.0, no constraint implementation reads from the context, but the plumbing is complete and the context carries real backend capabilities.
Summary
Functions
Creates a new context with default capabilities.
Creates a new context with the given capabilities.
Creates a new context with the given capabilities and provenance flag.
Types
@type t() :: %ExDatalog.Constraint.Context{ capabilities: ExDatalog.Capabilities.t(), provenance: boolean() }
Functions
@spec new() :: t()
Creates a new context with default capabilities.
Examples
iex> ctx = ExDatalog.Constraint.Context.new()
iex> ctx.capabilities.storage_type
:map
iex> ctx.provenance
false@spec new(ExDatalog.Capabilities.t()) :: t()
Creates a new context with the given capabilities.
Examples
iex> caps = %ExDatalog.Capabilities{storage_type: :ets, indexed_lookup: true}
iex> ctx = ExDatalog.Constraint.Context.new(caps)
iex> ctx.capabilities.storage_type
:ets
iex> ctx.provenance
false@spec new(ExDatalog.Capabilities.t(), boolean()) :: t()
Creates a new context with the given capabilities and provenance flag.
Examples
iex> caps = %ExDatalog.Capabilities{storage_type: :ets}
iex> ctx = ExDatalog.Constraint.Context.new(caps, true)
iex> ctx.provenance
true