Major Section: OTHER
ACL2 users often find its careful syntax checking to be helpful during code
development. Sometimes it is even useful to do code development in
logic mode, where ACL2 can be used to check termination of
(mutually) recursive functions, verify guards, or even prove properties of
However, loading code using
include-book is much slower than using
load in raw Lisp, and in this sense ACL2 can get in the way
of efficient execution. Unfortunately, it is error-prone to use ACL2 sources
(or their compilations) in raw Lisp, primarily because a number of ACL2
primitives will not let you do so. Perhaps you have seen this error message
when trying to do so:
HARD ACL2 ERROR in ACL2-UNWIND-PROTECT: Apparently you have tried to execute a form in raw Lisp that is only intended to be executed inside the ACL2 loop.Even without this problem it is important to enter the ACL2 loop (see lp), for example in order to set the
cbdand (to get more technical) the readtable.
ACL2 provides a ``raw mode'' for execution of raw Lisp forms. In this mode,
include-book reduces essentially to a Common Lisp
generally, the ACL2 logical
world is not routinely extended in raw mode
(some sneaky tricks are probably required to make that happen). To turn raw
mode off or on:
:set-raw-mode t ; turn raw mode on :set-raw-mode nil ; turn raw mode off
P'' (suggesting something like program mode, but more so).
Typical benefits of raw mode are fast loading of source and compiled files
and the capability to hack arbitrary Common Lisp code in an environment with
the ACL2 sources loaded (and hence with ACL2 primitives available). In
addition, ACL2 hard errors will put you into the Lisp debugger, rather than
returning you to the ACL2 loop, and this may be helpful for debugging;
see hard-error and see illegal, but also see break-on-error. However, it
probably is generally best to avoid raw mode unless these advantages seem
important. We expect the main benefit of raw mode to be in deployment of
applications, where load time is much faster than the time required for a
include-book, although in certain cases the fast loading of
books and treatment of hard errors discussed above may be useful during
Raw mode is also useful for those who want to build extensions of ACL2. For example, the following form can be put into a certifiable book to load an arbitrary Common Lisp source or compiled file.
(progn! (defttag my-application) (set-raw-mode t) (load "some-file"))Also see
books/misc/hacker.lisp, see defttag, and see progn!.
Below are several disadvantages to raw mode. These should discourage users
from using it for general code development, as
program mode is
-- Forms are in essence executed in raw Lisp. Hence: -- Syntax checking is turned off; and -- Guard checking is completely disabled. -- Table events, including
logic, are ignored, as are many other
comp. -- Soundness claims are weakened for any ACL2 session in which raw mode was ever entered; see defttag. -- The normal undoing mechanism (see ubt) is not supported.
We conclude with some details.
Printing results. The rules for printing results are unchanged for raw
mode, with one exception. If the value to be printed would contain any Lisp
object that is not a legal ACL2 object, then the
[Note'' occurs one space over in the
second example, and no result is printed in the third example.
ACL2 P>(find-package "ACL2") [Note: Printing non-ACL2 result.] #<The ACL2 package> ACL2 P>(mv nil (find-package "ACL2") state) [Note: Printing non-ACL2 result.] #<The ACL2 package> ACL2 P>(mv t (find-package "ACL2") state) ACL2 P>(mv 3 (find-package "ACL2")) [Note: Printing non-ACL2 result.] (3 #<The ACL2 package>) ACL2 P>If you have trouble with large structures being printed out, you might want to execute appropriate Common Lisp forms in raw mode, for example,
(setq *print-length* 5)and
(setq *print-level* 5).
Packages. Raw mode disallows the use of
defpkg. If you want to
create a new package, first exit raw mode with
you can subsequently re-enter raw mode with
:set-raw-mode t if you