lang: funcs: facts: Add CallableFunc implementation for fact

Add an initial implementation for this wrapper function.
purpleidea · purpleidea · Oct 3, 2023 · Dec 6, 2023 · Dec 6, 2023 · Dec 6, 2023
commit 299ec4acddabfce4418ef7314be62ef1db8cb530
diff --git a/lang/funcs/facts/facts.go b/lang/funcs/facts/facts.go
@@ -86,3 +86,16 @@ type Fact interface {
  Init(*Init) error
  Stream(context.Context) error
 }
+
+// CallableFunc is a function that can be called statically if we want to do it
+// speculatively or from a resource.
+type CallableFact interface {
+ Fact // implement everything in Fact but add the additional requirements
+
+ // Call this function with the input args and return the value if it is
+ // possible to do so at this time. To transform from the single value,
+ // graph representation of the callable values into a linear, standard
+ // args list for use here, you can use the StructToCallableArgs
+ // function.
+ Call() (types.Value, error)
+}
diff --git a/lang/funcs/facts/func.go b/lang/funcs/facts/func.go
@@ -79,3 +79,15 @@ func (obj *FactFunc) Init(init *interfaces.Init) error {
 func (obj *FactFunc) Stream(ctx context.Context) error {
  return obj.Fact.Stream(ctx)
 }
+
+// Call means this function implements the CallableFunc interface and can be
+// called statically if we want to do it speculatively or from a resource.
+func (obj *FactFunc) Call() (types.Value, error) {
+
+ callableFact, ok := obj.Fact.(CallableFact)
+ if !ok {
+ return nil, fmt.Errorf("fact is not a CallableFact")
+ }
+
+ return callableFact.Call()
+}