The values of these symbols have a predefined meaning.
while others are simply flags whose value the user can change to affect
the operation of lisp system.
In all cases, only the value cell of the symbol is important, the function
The value of some of the symbols (like \fBER%misc\fP)
are functions - what this means is that the value cell of those symbols
either contains a lambda expression,
or symbol with a function binding.
The values of the special symbols are:
The number of garbage collections which have occurred.
If bound to a non nil value, then after each garbage collection and
subsequent storage allocation a summary of storage allocation will
If bound to a non nil value, then during each
a diagnostic message will be printed.
The function which is the error handler for all errors (see \(sc10)
The function which is the handler for the
error signal generated by the evaluation of the
The function which is the handler for the error
signal generated by the evaluation of the
The function which is the handler of the error
signal generated by one of the unclassified errors (see \(sc10).
Most errors are unclassified at this point.
The function which is the handler to be called
when an error has occurred which
has not been handled (see \(sc10).
The function which is the handler for the
error signal generated when a call to an undefined function
When bound to a non nil value this will prevent output to the standard
output port (poport) from reaching the standard output (usually a terminal).
Note that ^w is a two character symbol and should not be confused
with ^W which is how we would denote control-w.
The value of ^w is checked when the standard output buffer is flushed
or when the buffer overflows.
This is most useful in conjunction with ptport described below.
System error handlers rebind ^w to nil when they are invoked to assure
that error messages are not lost.
(This was introduced for Maclisp compatibility).
.Sa defmacro-for-compiling
The has an effect during compilation.
If non-nil it causes macros defined by defmacro to be
compiled and included in the
The UNIX environment in assoc list form.
is done, the value of errlist is saved away and control is thrown to
is then mapped over the saved away
This port is initially bound to the standard error file.
The value of this symbol, if bound, is the name of a function to handle
evalhook traps (see \(sc14.4)
The value of this symbol is a string which is the format to be used
by print to print flonums.
See the documentation on the UNIX function printf for a list
The value of this symbol, if bound, is the name of a function to handle
funcallhook traps (see \(sc14.4).
If non nil, then garbage collections will not be done automatically when
a collectable data type runs out.
This is the input radix used by the lisp reader.
It may be either eight or ten.
Numbers followed by a decimal point are assumed to be decimal regardless
The line length used by the pretty printer, pp.
but it is not at this time.
This symbol represents the null list and thus can be written ().
Any attempt to change the value will result in an error.
Initially bound to the standard input (usually the keyboard).
A read with no arguments reads from piport.
Initially bound to the standard output (usually the terminal console).
A print with no second argument writes to poport.
If this is a positive fixnum, then the \fIprint\fP function will print
no more than prinlength elements of a list or hunk and further elements
The initial value of prinlength is nil.
If this is a positive fixnum, then the \fIprint\fP function will print
only prinlevel levels of nested lists or hunks.
Lists below this level will be abbreviated by `&' and hunks below this
level will be abbreviated by a `%'.
The initial value of prinlevel is nil.
If bound to a port, then all output sent to the standard output will
also be sent to this port as long as this port is not also
the standard output (as this would cause a loop).
Note that ptport will not get a copy of whatever is sent to poport
if poport is not bound to the standard output.
The value of this is the current readtable.
It is an array but you should NOT try to change the value of the elements
of the array using the array functions.
This is because the readtable is an array of bytes and the smallest
unit the array functions work with is a full word (4 bytes).
This symbol always has the value t.
It is possible to change the value of this symbol for short
periods of time but you are strongly advised against it.
In a lisp system without /usr/lib/lisp/toplevel.l loaded, after a
is done, the lisp system will
the value of top-level if it is
This provides a way for the user to introduce his own top level interpreter.
When /usr/lib/lisp/toplevel.l is loaded, it sets top-level to franz-top-level
function so that once franz-top-level starts, it cannot
be replaced by changing top-level.
Franz-top-level does provide a way of changing
the top level however, and that is
If this is bound then after a
the top level function will
the value of this symbol rather than go through a read eval print