# System Function AT

 Z←L ⎕AT R returns the attributes of the objects named in R.
R is a character scalar, vector, or matrix consisting of the names of objects (e.g., variables, functions, or operators).
L is an integer scalar whose value is either 1, 2, 3, or 4.
Z is an integer vector or matrix.

If R is a scalar, it is treated as the name; if R is a vector, it is treated as a vector of names separated from one another by one or more blanks; if R is a matrix, each row is treated as a single name surrounded by zero or more blanks.

If R consists of a single name, Z is a vector; otherwise Z is a matrix with as many rows as there are names in R.

The number of columns in Z depends upon the value of L.

• If L is 1, the result describes the Valences of the objects named in R and has three columns consisting of
[1] Whether or not there is an Explicit result (1 or 0): This value is 1 for variables and for functions/operators that return a result; 0 otherwise.
[2] The Function Valence (0, 1, or 2): This value is 0 for a non-function or for a niladic function, 1 for a monadic function or for a monadic derived function from an operator, and 2 for a dyadic or ambivalent function or for a dyadic or ambivalent derived function from an operator.
[3] The Operator valence (0, 1, or 2): This value is 0 for a non-operator, 1 for a monadic operator, and 2 for a dyadic operator.

• If L is 2, the result describes the Fix Time of the objects named in R and has seven columns consisting of
[1] Year
[2] Month
[3] Day
[4] Hour
[5] Minute
[6] Second
[7] Millisecond

If an object named in R is not a user-defined function/operator, the corresponding row in the result is all 0. All times are in UTC and represent the time the function was last modified.

• If L is 3, the result describes the Execution Properties of the objects named in R and has four columns consisting of
[1] Whether or not the object is Nondisplayable (1 or 0)
[2] Whether or not the object is Nonsuspendable (1 or 0)
[3] Whether or not the object Ignores weak interrupts, i.e. Ctrl-C or Ctrl-Break (1 or 0)
[4] Whether or not the object Converts non-resource errors to DOMAIN ERRORs (this value is always 0)

If an object named in R is a variable, the corresponding row in the result is all 0. If an object named in R is a primitive or system function, the corresponding row in the result is 1 1 1 0. If an object named in R is a function array, train, or magic function, the corresponding row in the result is 0 1 1 0.

• If L is 4, the result describes the Object Size of the objects named in R and has two columns consisting of
[1] The object's size consisting of the object header and data sizes
[2] The object's data size only.

## Examples

⎕AT - Quad AT - Object Summary Attributes - sample dyadic calls (re workspace user-function attributes):

```      2 ⎕AT ⊃'UCase' 'LCase'  ⍝ Request to show 'Date/Time last modified' Attribute for two workspace functions
2015 2 4 0 23 55 926          ⍝ Yr Mo Day Hr Min Sec Milli-Secs format - same format as ⎕TS (quad time stamp)
2015 2 4 0 23 37 839
X←⊃'UCase' 'LCase'
⍴X
2 5
X
UCase
LCase
(1 ⎕AT X),'|',(2 ⎕AT X),'|',(3 ⎕AT X),'|',(4 ⎕AT X)
1 1 0 | 2015 2 4 0 23 55 926 | 0 0 0 0 | 19626 6434
1 1 0 | 2015 2 4 0 23 37 839 | 0 0 0 0 | 18424 6448

⍝  1 1 0 = {Yes Explicit Function Result Z} {Monadic Function Valence} {Non-Operator}  : 1 ⎕AT fcn-names (Results)
⍝  Date/Time last edited                                                               : 2 ⎕AT fcn-names
⍝  0 0 0 0 = {Not yet implemented in NARS}                                             : 3 ⎕AT fcn-names
⍝  19626 6434 = {object header and data sizes, # bytes} {data size only, # bytes}      : 4 ⎕AT fcn-names

```

Note: ⎕AT is a dyadic form system function, you cannot assign a value to it.

System Variables (A value may be assigned to these except for ⎕DM)
ALX CT DM DT ELX FC FEATURE FPC IC IO
LR LX PP PR PW RL SA WSID
Niladic System Functions (a value cannot be assigned to these)
A AV EM ET LC NNAMES NNUMS SI SYSID SYSVER
T TC TCBEL TCBS TCESC TCFF TCHT TCLF TCNL TCNUL
TS WA
Monadic or dyadic system functions (a value cannot be assigned to these)
AT CR DC DFT DL DR EA EC ERROR ES
EX FMT FX MF NAPPEND NC NCREATE NERASE NINFO NL
NLOCK NREAD NRENAME NREPLACE NRESIZE NSIZE NTIE NUNTIE STOP TF
TRACE UCS VR
Note that quad functions and variables (except for the ⎕A family of functions) are case insensitive