Intro15

15. Defined Adverbs


Names may be assigned to adverbs, as they are to nouns and verbs:

   a=:1 2 3 4 5
   prefix=: 
   < prefix 'abcdefg'
+-+--+---+----+-----+------+-------+
|a|ab|abc|abcd|abcde|abcdef|abcdefg|
+-+--+---+----+-----+------+-------+
   +/ prefix a
1 3 6 10 15

Moreover, new adverbs result from a string of adverbs
(such as /) and from a conjunction
together with one of its arguments.
Such adverbs can be defined by assigning names. Thus:

   IP=: /                     NB. Insert Prefix
   + IP a
1 3 6 10 15
   with3=: &3
   % with3 a
0.333333 0.666667 1 1.33333 1.66667
   ^ with3 a
1 8 27 64 125
   I=: ^: _1                   NB. Inverse adverb
   *: I a
1 1.41421 1.73205 2 2.23607
   + IP I 1 3 6 10 15
1 2 3 4 5
   ten=: 10&
   ^. ten 5 10 20 100
0.69897 1 1.30103 2
   #. ten 3 6 5
365
   from=: -~ 
   into=: %~
   10 into 17 18 19
1.7 1.8 1.9
   10 from 17 18 19
7 8 9
   i=: "_1                NB. Apply to items
   {. i i. 3 4
0 4 8

Exercises