MTS 8: LISP and SLIP in MTS
Page Revised January 1983 June 1976
27 ARG was called where there is no outstanding no-spread
function, or ARG was called with two arguments, where the
second argument is not the name of any outstanding no-spread
dummy argument.
28 ARG was called with a number which is nonpositive or greater
than the number of arguments passed to the no-spread
function.
29 An attempt to define an external SUBR with an illegal type
specification.
30 LISP could not find or could not load an external routine
which was defined. The error expression is the file name or
entry point name which was given.
31 A subscript in an array specification was nonpositive or
exceeded the limits of that subscript position.
32 GETWORLD was called with an argument which is not a valid
ticket.
33 A call to RES was attempted when there was no outstanding
attention, timer, or STEP error, or the attention error at
that level was an immediate (double) attention.
| 34 A call to CHECKPOINT or RESTORE which did not specify a line
file, or a call to RESTORE which specified a file which was
not produced by the current CHECKPOINT.
35 The number of steps specified in a STEP call have been
completed.
36 A call to RETURN, UNEVAL, DISPLAY, or MODIFY tried to
reference an EVAL block which did not exist.
37 A call to DISPLAY or MODIFY, which specified F mode,
identified an EVAL block which was not an executing PROG,
COND, SELECT, or function with a LAMBDA definition.
38 Unbalanced angle brackets were encountered.
SPECIAL FEATURES ________________
The STATUS Function ___________________
The STATUS function is used for two purposes--to get and to set the
values of system switches and parameters. There are two types of status
calls. The first interrogates the system and returns the value of a
66 LISP

MTS 8: LISP and SLIP in MTS
June 1976
system parameter, and the second supplies a value which is to replace
the system parameter.
The various system parameters are identified by status codes. Type I
status codes are used to get and set parameters associated with buffers,
files, arrays, and atoms. To get one of these parameter values, the
argument to STATUS will be of the form:
(STATUS-CODE NAME)
where NAME is the appropriate I/O destination atom, array, or atom.
To set one of these parameters, the argument to STATUS will be of the
form:
(STATUS-CODE NAME VALUE)
where VALUE is the new value for the parameter.
Type II status codes are used for general system switches and
parameters. To get and set these parameters, the argument to STATUS
will be of the form:
STATUS-CODE Gets parameter values.
(STATUS-CODE VALUE) Sets parameter values.
Whether getting or setting a system parameter value, the previous
value will be returned from STATUS. If more than one argument to STATUS
is given, a list of the previous values of all the parameters used in
the call will be returned.
Note: In a call to STATUS, the status code parameter may be any
atom, and its value (which must be a legal status code) will be used as
the actual status code. This allows mnemonic definitions to be given to
status codes, e.g.,
(STATUS (SETPFX ABUF NIL))
where the VALUE of SETPFX is 10.
In addition, where a status code is set to some numeric value, the
VALUE it is set to may also be any atom, and the VALUE of the atom will
be used. For example,
(STATUS (SETGC GCBIG))
where the VALUE of SETGC is 45, and the VALUE of GCBIG is a numeric
atom.
LISP 67