MTS 8: LISP and SLIP in MTS
June 1976
Type I Status Codes--Buffer, File, Array, and Atom Characteristics __________________________________________________________________
Code Meaning ____ _______
1 This status code is used to get or set the error atom
associated with a particular error number. (See the subsec-
tion "Error Recovery and Debugging Procedures" above for an
explanation of the error atom.) The get form is (STATUS (1
N)), which will return the error atom associated with error
number n. The set form is (STATUS (1 N A)), which will set
A to be the new error atom associated with error number N.
From that time on, a type N error will cause the value of A
to be used as the error form.
2 This status code is used to get or set the READMACRO switch
for an atom. Its argument must be an atom. If the
READMACRO switch is NIL, then the atom will not be recog-
nized as a READMACRO. If the switch is non-NIL, then
whenever the atom appears as part of an S-expression which
is read in, it will be treated as a READMACRO as described
in the subsection "READMACRO and PRINTMACRO Functions." The
initial value of this parameter for all atoms is NIL.
3 (Reserved.)
4 This status code is used to get or set the PRINTMACRO switch
for an atom. It has the same significance as the READMACRO
switches, except that if this switch is enabled, whenever
the atom is printed into a buffer, the atom will be treated
as a PRINTMACRO as described in the subsection "READMACRO
and PRINTMACRO Functions."
5 This status code is used to get or set the disposition of
characters in the READ scan table. It allows the user to
alter LISP syntax. The argument must be a literal atom.
The parameter value given will replace the scan table value
for the first character of that atom. The legal scan table
values, and their significance to READ, are as follows:
0 Insignificant characters (e.g., blanks).
4 Left parenthesis "(".
8 Right parenthesis ")".
12 End-of-line (or semicolon).
16 Period. Signifies dotted-pair or number.
20 Plus sign "+". Signifies beginning of a number.
24 Minus sign "-". Signifies beginning of a number.
28 Single character atom (for READMACRO characters.)
32 Quote character. Special processing.
36 Number starter (0-9).
40 Literal starter (A-Z).
44 Quote character. Special processing.
48 Left angle bracket "".
52 Right angle bracket "".
68 LISP

MTS 8: LISP and SLIP in MTS
June 1976
6 This status code is used to get or set the disposition of
characters in the READ literal break table. The argument
given must be a literal atom. The parameter value given
will replace the break table value for the first character
of that atom. The literal break table values are:
0 May be part of a literal atom’s PNAME.
1 Break character--end of literal PNAME.
7 This status code is used to get or set the disposition of
characters in the READ number break table. The argument
given must be a literal atom. The parameter value given
will replace the break table value for the first character
of that atom. The number break table values are as follows:
0 Numeral (0-9).
1 Normal end of a number (blank, comma, end-of-line,
etc.).
2 Floating-point period.
3 Hexadecimal digit (A-F).
4 Neither a break character nor part of a number. Back
up and process this atom as a literal atom.
Note: Codes 0, 2, and 3 must be used only with the
characters listed after them. Attempts to do numeric
conversion after improper use of these codes will generate
numeric exceptions.
8 This status code is used to get the number of dimensions of
an array. Its argument must be an array name.
9 This status code is used to get or set the size of a buffer
(i.e., the right margin). The buffer size includes the
buffer prefix (if any), and may not exceed 255 characters.
10 This status code is used to get or set the length of the
buffer prefix for a buffer. Evaluating the function (STATUS
(10 IODA T)) freezes the current contents of the buffer
associated with IODA as a prefix, and returns the length of
the previous prefix. Evaluating the function (STATUS (10
IODA NIL)) releases the prefix. At that point, the prefix
will be treated as the contents of the buffer, and will
appear at the beginning of the next output line, unless a
(TAB 1) or (TERPRI) is performed to get rid of it.
11 This status code is used to get or set the current READ
pointer for a buffer. The argument given must be an I/O
destination atom. The value of this parameter is not
computed relative to any prefix which may exist. It is not
affected by doing print operations into the buffer, but it
is reset to zero whenever a TERPRI or a physical write
operation is performed. A TAB or SKIP to a smaller number
will reset the pointer to the smaller number.
LISP 69