eval =: 1 : ' a: 1 : m'
u2m =: 1 : (':';'x m eval y')
v2n =: 2 : (':';'x (u v eval) y')
v2nS =: 2 : (':';'x (v eval u) y')
u2m is limited to monadic result verbs, but because you can build the
parameters, you can also create bound verbs:
'+' (] (' eval' u2m)~ '3&' ,[) 2
5
the parameter to u2m is a string that is an adverb, and where that adverb takes
a noun as a parameter.
(' eval' u2m) is a verb, that can be set to passive (~). The above can also be
called as
('3&+' (' eval' u2m) ]) 2
5
but the point of the previous example was to show that the string could be
built as a verb, even though the adverb can only accept nouns.
can also be used to build adverbs such as amend. example where 3 is a constant
replacement value, but the index to update is passed through x.
1 (('13&(' , '})' ,~ ":@:[)(' eval'u2m) ])i.5
0 13 2 3 4
0 ([ (+:`+ v2n ' @.') ]) 2
4
(1: (+/ v2n ' "') ]) i. 2 3
3 12
For v2n, a conjunction is first bound to its u argument (v2nS binds v first
instead) The first bound argument does not need to be a noun. The result is a
verb that will take x to complete the conjunction the "normal way" that it
would be when first bound into an adverb. The n parameter though, can now be a
verb.
the above 2 examples do:
+:`+@.0 ] 2
+/"1 i. 2 3
though I haven't found a way to make the v2n result a dyad, you might use u2m
and eval instead:
1 2 ((":@:[ , ' &(+"' , ')' (,~ ":) 0 , 1:) ('eval' u2m) ]) i.3
1 2 3
2 3 4
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