enlist

Make a list

enlist x    enlist[x]    enlist[x;y;z;…]

Returns a list with its argument/s as items.

The most common use is to make a 1-item list. An atom is not a one-item list: enlist and first convert between the two.

q)a:10
q)b:enlist a
q)c:enlist b
q)type each (a;b;c)
-7 7 0h
q)a~b
0b
q)a~first b
1b
q)b~c
0b
q)b~first c
1b

The result has as many items as the keyword is applied to.

q)show a:enlist[til 5;`ibm`goog;"hello"]
0 1 2 3 4
`ibm`goog
"hello"
q)count a
3

Unlike user-defined functions, enlist is not limited to 8 arguments.

q)count b:enlist[0;`1;"two";3;`four;5;`6;"seven";8;`nine]
10

Where x is a dictionary, the result is a 1-item table.

q)enlist `a`b`c!(1;2 3; 4)
a b   c
-------
1 2 3 4

Atoms to lists

To ensure all items in a list are themselves lists and not atoms, use (),, which leaves lists unchanged.

For example, {(),x} each foo converts any atoms in list foo into singleton lists.

Assign a 1-item list

While enlist returns a 1-item list, if all you need to do is assign it to a name not presently defined, you can exploit the fact that foo,: does not require foo to be defined.

q)a:enlist[3]
q)b,:3
q)a~b
1b