anchor.diff: -%% Copyright (c) 2008-2014 Robert Virding
  +%% Copyright (c) 2008-2017 Robert Virding
   %%
   %% Licensed under the Apache License, Version 2.0 (the "License");
   %% you may not use this file except in compliance with the License.
  
positive.code: eval_gexpr([call,?Q(erlang),?Q(Fun)|As], Env) ->
      Ar = length(As),
      case lfe_internal:is_guard_bif(Fun, Ar) of
  	true -> erlang:apply(erlang, Fun, eval_glist(As, Env));
          false -> illegal_guard_error()
      end;
  eval_gexpr([Fun|Es], Env) when is_atom(Fun), Fun =/= call ->
  
negative.code: unbound_symb_error(Sym) ->
      eval_error({unbound_symb,Sym}).
  
  undefined_func_error(Func) ->
      eval_error({undefined_func,Func}).
  
  bad_form_error(Form) ->
      eval_error({bad_form,Form}).
  