Function newProgram

cel/program.go:173–292

newProgram creates a program instance with an environment, an ast, and an optional list of ProgramOption values. If the program cannot be configured the prog will be nil, with a non-nil error response.

(e *Env, a *ast.AST, opts []ProgramOption)

//
// If the program cannot be configured the prog will be nil, with a non-nil error response.
func newProgram(e *Env, a *ast.AST, opts []ProgramOption) (Program, error) {
	// Build the dispatcher, interpreter, and default program value.
	disp := interpreter.NewDispatcher()

	// Ensure the default attribute factory is set after the adapter and provider are
	// configured.
	p := &prog{
		Env:            e,
		plannerOptions: []interpreter.PlannerOption{},
		dispatcher:     disp,
		costOptions:    []interpreter.CostTrackerOption{},
	}

	// Configure the program via the ProgramOption values.
	var err error
	for _, opt := range opts {
		p, err = opt(p)
		if err != nil {
			return nil, err
		}
	}

	e.funcBindOnce.Do(func() {
		var bindings []*functions.Overload
		e.functionBindings = []*functions.Overload{}
		for _, fn := range e.functions {
			bindings, err = fn.Bindings()
			if err != nil {
				return
			}
			e.functionBindings = append(e.functionBindings, bindings...)
		}
	})
	if err != nil {
		return nil, err
	}

	// Add the function bindings created via Function() options.
	err = disp.Add(e.functionBindings...)
	if err != nil {
		return nil, err
	}

	// Set the attribute factory after the options have been set.
	var attrFactory interpreter.AttributeFactory
	attrFactorOpts := []interpreter.AttrFactoryOption{
		interpreter.EnableErrorOnBadPresenceTest(p.HasFeature(featureEnableErrorOnBadPresenceTest)),
	}
	if a.SourceInfo().HasExtension("json_name", ast.NewExtensionVersion(1, 1)) {
		if !e.HasFeature(featureJSONFieldNames) {
			return nil, errors.New("the AST extension 'json_name' requires the option cel.JSONFieldNames(true)")
		}
	}
	// Configure the type provider, considering whether the AST indicates whether it supports JSON field names
	if p.evalOpts&OptPartialEval == OptPartialEval {
		attrFactory = interpreter.NewPartialAttributeFactory(e.Container, e.adapter, e.provider, attrFactorOpts...)
	} else {
		attrFactory = interpreter.NewAttributeFactory(e.Container, e.adapter, e.provider, attrFactorOpts...)