Function ProtoAsDeclaration

cel/decls.go:387–428

ProtoAsDeclaration converts a canonical celpb.Decl value describing a variable or function into an EnvOption.

(d *celpb.Decl)

// ProtoAsDeclaration converts a canonical celpb.Decl value describing a variable or function into an EnvOption.
func ProtoAsDeclaration(d *celpb.Decl) (EnvOption, error) {
	switch d.GetDeclKind().(type) {
	case *celpb.Decl_Function:
		overloads := d.GetFunction().GetOverloads()
		opts := make([]FunctionOpt, len(overloads))
		for i, o := range overloads {
			args := make([]*Type, len(o.GetParams()))
			for j, p := range o.GetParams() {
				a, err := types.ProtoAsType(p)
				if err != nil {
					return nil, err
				}
				args[j] = a
			}
			res, err := types.ProtoAsType(o.GetResultType())
			if err != nil {
				return nil, err
			}
			if o.IsInstanceFunction {
				opts[i] = decls.MemberOverload(o.GetOverloadId(), args, res)
			} else {
				opts[i] = decls.Overload(o.GetOverloadId(), args, res)
			}
		}
		return Function(d.GetName(), opts...), nil
	case *celpb.Decl_Ident:
		t, err := types.ProtoAsType(d.GetIdent().GetType())
		if err != nil {
			return nil, err
		}
		if d.GetIdent().GetValue() == nil {
			return Variable(d.GetName(), t), nil
		}
		val, err := ast.ProtoConstantAsVal(d.GetIdent().GetValue())
		if err != nil {
			return nil, err
		}
		return Constant(d.GetName(), t, val), nil
	default:
		return nil, fmt.Errorf("unsupported decl: %v", d)
	}
}