I am attempting to learn J and the book I am using says this is the proper way to define a monadic function
function =: 3:0 function statements
so I followed this format and wrote the folding code. Can you tell me why this is throwing a syntax error when I try to call it with input but if I just call p it returns 3
h=:>:@i.@<.@-: :[: NB. gets all integers less than half of the input :[: forces error if used dyadicly
d=:(0&=|)~ h :[: NB. gets list where if one is set that index from h was a factor of the input y :[: forces error if used dyadicly
p=: 3:0 NB. tells us p is a monadic function
t =: d y
a =: i. 1
while. 1<#t
if. t~:0
a =: a, #t
end.
t=: _1 }. t NB. found first mistake wrong bracket but fixing that doesn't fix it
end.
a*1
)
NB. p gets a list of all integers that are factors of y
p 4
| syntax error
| p 4
p
3
NB. h and d run fine
h 4
1 2
h 7
1 2 3
d 7
1 0 0
d 4
1 1