Standard ML of New Jersey (SML/NJ)
SML/NJ is a popular implementation of the Standard ML programming language that was co-developed jointly by Bell Laboratories and Princeton University. It is released under a BSD like license.
References:
Questions tagged [smlnj]
866 questions
4
votes
1 answer
Convert a Haskell function to SML
I'm trying to convert a Haskell function, which displays a boolean formula, to a SML function.
The function:
data Formula
= Atom String
| Neg Formula
| Conj Formula Formula
| Disj Formula Formula
precedence :: Formula ->…
TheAptKid
- 1,559
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4
votes
1 answer
How to flatten a list non-recursively in sml/nj?
fun flat [] = []
| flat (l::ls) = l @ flat ls;
This will flatten a list.
Is there a way to non recursively do the same operation? Perhaps with HOFs?
Dickson
- 43
- 1
- 3
4
votes
1 answer
How do I change a single char to an int in sml/nj
I am just trying to change the char to int and return the int.
Graeme
- 41
- 2
4
votes
5 answers
BigInt for Standard ML/NJ
Is there a Java BigInt equivalent for Standard ML? The normal int type throws an exception when it overflows.
rezusr
- 63
- 1
- 5
4
votes
3 answers
Running Standard ML on Windows
I have been looking for some good documentation on how to get Standard ML running on windows. Does anyone have a good guide on this?
I have tried compiling sml/nj in cygwin, using this guide: http://www.smlnj.org/install/index.html
$…
user833970
- 2,729
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- 41
3
votes
1 answer
Foldl return a Tuple in SML?
The problem I'm working on needs to take in a list of integers and return the average of those numbers. It needs to fit a specific format that looks like this...
fun average (n::ns) =
let
val (a,b) = fold? (?) ? ?
in
real(a) / real(b)
end;
I'm…
MCR
- 1,633
- 3
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- 36
3
votes
1 answer
SML - collecting words in a trie using continuations
I have a
datatype trie = Node of char * (trie ref) list | Empty
And I want to collect all the words in the trie, using these two mutually recursive functions:
words_in_trie: trie -> (char list list -> 'a) -> 'a
all_words: trie ref list -> (char…
Lanaru
- 9,421
- 7
- 38
- 64
3
votes
1 answer
SMLNJ want to remove "val it = () : unit" from every print statement execution
I am writing sml programs which run on SML/NJ and MLton (not interactive). When I use print statements in the the sml file, SML/NJ always adds
val it = () : unit
to the output, which clutters up the output. MLton does not do this.
Is there a…
DougT
- 231
- 1
- 10
3
votes
2 answers
find whether a string is substring of other string in SML NJ
In SML NJ, I want to find whether a string is substring of another string and find its index. Can any one help me with this?
Harish
- 7,589
- 10
- 36
- 47
3
votes
2 answers
How to coerce a type in SML (like casting)
I'm creating a structure of Rationals (int * int) and one of my functions is:
fun diff ((n, d), (n', d')) =
let
val (top, bot) = sum ((n, d), (~n', d'))
in
(top / gcd(top, bot), bot / gcd(top, bot))
end
gcd gives me the greatest…
Kai
- 3,997
- 4
- 30
- 36
3
votes
2 answers
How can I customize the SML/NJ interactive loop?
I'm new to Standard ML and I'm trying to get my head around the SML/NJ runtime environment. I want to adapt it to my needs. Specifically, I want to:
Use IntInf by default
Prevent it from truncating strings and IntInf to 70 characters.
Here's what…
Barry Brown
- 20,233
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3
votes
1 answer
Defined functions in structures in SML results in "value type in structure does not match signature spec"
It has been quite a while since I've been programming in SML and now I'm stuck on what looks to me a very simple issue.
I'm defining a datatype like
datatype 'a Something = Something of 'a
then I'm defining a signature as follows
signature A = sig
…
elTomato
- 333
- 3
- 11
3
votes
0 answers
Printing constructor name in SML
I would like to know whether there would be a way to print the name of the constructor of a datatype from a function in SML. I could find ways to do this in Haskell by deriving the datatype from libraries like show but not in SML.
I need this…
blueconch
- 31
- 2
3
votes
1 answer
SML: Exception while reading a line of integers
fun parse file =
let
(* A function to read an integer from specified input. *)
fun readInt input =
Option.valOf (TextIO.scanStream (Int.scan StringCvt.DEC) input)
in
(Array.update(acc,readInt inStream, f+1);…
tonythestark
- 519
- 4
- 15
3
votes
2 answers
Return a list of even numbers from a list of integer pairs in sml
I have the following question "Given a list of integer pairs, write a function to return a list of even numbers in that list in sml".
this is what I've achieved so far
val x = [(6, 2), (3, 4), (5, 6), (7, 8), (9, 10)];
fun isEven(num : int) =
…
John Smith
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