For me the flavor of J is functions (verbs), operators (adverbs and
conjunctions), and arrays: the J programmer thinks at this level of abstraction
to solve his problems, and the extended example below intends to give visitors
a
taste of this flavor.
However, this omits the use of J for windows programming. How would you
describe the J flavor of that, and what taste would you give visitors?
Here is my extended taste of "functions, operators, arrays" for a visitor.
]L =: i. 4 NB. assign (=:) and display (]) a "line" (vector) of 4 integers
0 1 2 3
]P =: i. 2 4 NB. a two-line "page" (matrix)
0 1 2 3
4 5 6 7
]B =: i. 3 2 4 NB. a three page "book" (array)
0 1 2 3
4 5 6 7
8 9 10 11
12 13 14 15
16 17 18 19
20 21 22 23
L NB. show L
0 1 2 3
+/ L NB. operator / inserts function + between items, we see sum
6
P
0 1 2 3
4 5 6 7
+/ P NB. items of a page are its lines, we see the sum of two lines
4 6 8 10
B
0 1 2 3
4 5 6 7
8 9 10 11
12 13 14 15
16 17 18 19
20 21 22 23
+/ B NB. items of a book are its pages, we see sum of three pages
24 27 30 33
36 39 42 45
L NB. show L
0 1 2 3
+/\ L NB. operator \ applies +/ to "prefixes", gives cumulative sums
0 1 3 6
P
0 1 2 3
4 5 6 7
+/\ P
0 1 2 3
4 6 8 10
B
0 1 2 3
4 5 6 7
8 9 10 11
12 13 14 15
16 17 18 19
20 21 22 23
+/\ B
0 1 2 3
4 5 6 7
8 10 12 14
16 18 20 22
24 27 30 33
36 39 42 45
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