[CSNOBOL4] Decimal to Binary #2

Many thanks to Gordon Peterson who took my non-idiomatic code and improved it both in size and speed, viz

         DEFINE("BIN(N)")                            :(BIN_END)
BIN      BIN = (GT(N,1) BIN(N / 2), ) REMDR(N,2)     :(RETURN)
BIN_END

This is guru level stuff.

I'm also grateful to Fred Weigel who first responded to my posting in the Snobol Yahoo! Group and made some very useful suggestions. He points out that Gordon's solution is a prime candidate for DEXP, viz:

dexp('bin(n) = (gt(n, 1) bin(n / 2), ) remdr(n, 2)')

That's enough CSNOBOL4 for now, though if you do want to spend some time with it (Windows or Linux), I'd suggest using Rafal M. Sulejman's TkSLIDE.

© Copyright Bruce M. Axtens, 2015

[CSNOBOL4] Decimal to Binary

Okay, I think this is the last of the solutions to Binary Digits. Thie one's in CSNOBOL4. Kudos to Phil Budne for maintaining and expanding this amazing programming language.

The code below, like all the ones before it, is recursive.

        DEFINE('BIN(N,STR)')              :(BIN_END)
BIN     EQ(N,0)                           :S(NZERO)
        BIN = BIN(N / 2, REMDR(N,2) STR)  :S(RETURN)
NZERO   BIN = EQ(SIZE(STR),0) '0'         :S(RETURN)
        BIN = STR                         :(RETURN)
BIN_END

        OUTPUT = BIN(0)
        OUTPUT = BIN(5)
        OUTPUT = BIN(50)
        OUTPUT = BIN(9000)
END

© Copyright Bruce M. Axtens, 2015

[FBSL] Decimal to Binary

Having solved the Binary Digits task in mLite, I thought I'd have a go in FBSL. Kudos to the FBSL team for a very useful and powerful Windows scripting language. Even ABAP users can leverage it!

The code below, expressed in v3.5 RC form, follows the mLite fairly closely.

#AppType Console
function Bin(byval n as integer, byval s as string = "") as string
 if n > 0 then return Bin(n \ 2, (n mod 2) & s)
 if s = "" then return "0"
 return s
end function

print Bin(5)
print Bin(50)
print Bin(9000)

pause

It was during the testing of this code that it dawned on me that the mLite wasn't handling the binary 0; appropriately. Thus those who notice such things will discover a subtle change in the mLite posting.

© Copyright Bruce M. Axtens, 2015

[mLite] Convert to Binary Notation

A short diversion: the Standard ML dialect called mLite is where I go for the intellectual challenge of thinking in a functional programming way. Kudos to Nils M. Holm for developing it. mLite is one of the languages I use to solve RosettaCode tasks, in this case, Binary Digits.

This turned out to be a fairly simple task and only took me a few minutes to solve. Granted, I reused some code from the logarithm calculator of a few postings ago, but that was just for the conversion of a list of numbers to their printable form.

fun binary
   (0, []) = "0"
 | (0, x) = implode ` map (fn x = if int x then chr (x + 48) else x) x
 | (n, b) = binary (n div 2, n mod 2 :: b)
 | n = binary (n, [])
; 

The gist of that is

• pass in a number and recurse with the number and an empty list.
  
• With a number that isn't zero recurse with the number divved by 2 and the list prepended with the number modded by 2.
  
• Keep going until the number is zero. At that point, convert the answer's digits to string representation and implode them into a single string.
  
• If the number is zero and there are no digits, return "0"

Might get back to some VB6 next. Or javascript. © Copyright Bruce M. Axtens, 2015