[Jprogramming] FizzBuzz

[Dan Bron]

Others have posted solutions, so I'll provide:

  (A) A different fundamental strategem
  (B) A generalizing extension

The final generalized extension is a bit cryptic (as a result of my "session programming" m.o.) so a bit of exegesis:

First, we will use monadic amend as the fundamental strategem:
 
	   fb   =:  verb define
	 
	       z =.  ":&.> y
	       z =.  (#. |: 0 = 3 5 |/ y) } z , |: (#z) $ ,: ;: 'Fizz Buzz FizzBuzz'

	       ;:^:_1 z
	   )
	      
	   fb i. 5
	FizzBuzz 1 2 Buzz 4
	   
Translating that to tacit:

	   fbT   =:  [: ;:^:_1 ([: #.@:|: 0 = 3 5 |/ ])`(":&.> , [: |: # $ (,:<;._1 ' Fizz Buzz FizzBuzz')"_)}
	   
	   fbT i. 5
	FizzBuzz 1 2 Buzz 4
	   
Now we can write an adverb that will generalize the solution, and use it to generate our specific FizzBuzz:

	   Fb =: adverb define

	       'fac rplc' =. 2 ([: (,&<~ ;)/@:|:@:}. ] (; */)~&:;/@|:@#~ [ #.^:_1: i.@:(^ #)) m
		
	       [: ;:^:_1 ((1 + #fac) | 1 + 1 i:"1~ 0 = fac |~/~ ])`(":&.> , [: |: # $ (,: rplc)"_) } 
	   )


	   (3 5 ;"_1 ;: 'Fizz Buzz')        NB.  Adverb's argument structure
	+-+----+
	|3|Fizz|
	+-+----+
	|5|Buzz|
	+-+----+


	   (3 5 ;"_1 ;: 'Fizz Buzz') Fb     NB.  Output of adverb
	[: ;:^:_1 (4 | 1 + 1 i:"1~ 0 = 5 3 15 |~/~ ])`(":&.> , [: |: # $ (,:<;._1 ' Buzz Fizz FizzBuzz')"_)}

	   
	   (3 5 ;"_1 ;: 'Fizz Buzz') Fb i. 5
	FizzBuzz 1 2 Fizz 4

And extend the adverb to make the the interface more convenient:
	   
	   FB =: adverb define
	
	       if.  (# *.&:(=&2) {:) $ m do.

	           'fac rplc' =. 2 ([: (,&<~ ;)/@:|:@:}. ] (; */)~&:;/@|:@#~ [ #.^:_1: i.@:(^ #)) m
		
	           [: ;:^:_1 ((1 + #fac) | 1 + 1 i:"1~ 0 = fac |~/~ ])`(":&.> , [: |: # $ (,: rplc)"_) } 
	       else.
	
	           m 2 : '(n ;"_1 ;:^:(0 = L.) m)' FB 
	       end.
	
	   )
	   
	   3 5 'Fizz Buzz' FB i. 5
	FizzBuzz 1 2 Fizz 4

I wonder if  f~/~  or   |:@:(f/~)  could be optimized.

-Dan