|  | ANSI Common Lisp  25 Environment  25.2 Dictionary of Environment 
 
 Syntax:
step
form
   {result}* 
Arguments and Values:
form - a form; evaluated as described below.
results - the values returned by the form.
 
Description:
step implements a debugging paradigm wherein the programmer
is allowed to step through the evaluation of a form.
The specific nature of the interaction,
including which I/O streams are used and
whether the stepping has lexical or dynamic scope,
is implementation-defined.
step evaluates form in the current environment.
A call to step can be compiled, but it is acceptable for an
implementation to interactively step through only those parts of the computation
that are interpreted.
 
It is technically permissible for a conforming implementation 
to take no action at all other than normal execution of the form.
In such a situation, 
(step form)
is equivalent to, for example,
(let () form). 
In implementations where this is the case, the associated documentation
should mention that fact.
 
?
 
See Also:
trace
 
Notes:
Implementations are encouraged to respond to the typing of ? 
or the pressing of a "help key" by providing help including a list of
commands.
 
Allegro CL Implementation Details:
See 
The 
original stepper and the subsequent sections
in 
debugging.htm 
for information on the Allegro CL implementation of the step macro. 
See also the top-level command  
:step. 
Note
the links are to the documentation for the current Allegro CL
version. Replace /current/ in the URL with the Allegro CL version
number to see similar documentation in earlier releases. |