sml

问题 In an Isabelle theory file, I can write simple one-line tactics such as the following: apply (clarsimp simp: split_def split: prod.splits) I find, however, when I start writing ML code to automate proofs, to produce an ML tactic object, these one-liners become rather verbose: clarsimp_tac (Context.proof_map ( Simplifier.map_ss (fold Splitter.add_split @{thms prod.splits}) #> Simplifier.map_ss (fn ss => ss addsimps [@{thm split_def}])) @{context}) 1 Is there an easier way to write the simple

问题 I have to write some code in ML and it is my first time I`m going to use the language. Is there any Development Environment for Standard ML? (preferably under Windows). I tried googling (and stackOverFlowing ! ) but all I found was plain compilers for Linux (at most with an interactive console), but no IDE nor Eclipse/NetBeans plugin. Any suggestions ? 回答1: How to Configure SML with Sublime Text 2 For those who prefer Sublime Text instead of Emacs as the editor of choice to program SML, the

问题 (* Write a function number_in_month that takes a list of dates and a month (i.e., an int) and returns how many dates in the list are in the given month.*) fun number_in_month(datelist : (int*int*int) list, month : int) = if null(tl (datelist)) then if #2(hd (datelist)) = month then 1 else 0 else if #2(hd (datelist)) = month then 1 + number_in_month(tl datelist, month) else number_in_month(tl datelist, month) (* Write a function number_in_months that takes a list of dates and a list of months

问题 I have a pretty simple code that's supposed to transform a list of tuples (int * string), into two lists, one list of ints and one list of strings - basically a list of tuples into a tuple of lists. fun unzip_single_int[] : int list = [] | unzip_single_int(x::xs) : int list = x :: unzip_single_int(xs) fun unzip_single_string[] : string list = [] | unzip_single_string(x::xs) : string list = x :: unzip_single_string(xs) fun unzip[] : (int list * string list) = ([], []) | unzip([twopls]) : (int

问题 I have a pretty simple code that's supposed to transform a list of tuples (int * string), into two lists, one list of ints and one list of strings - basically a list of tuples into a tuple of lists. fun unzip_single_int[] : int list = [] | unzip_single_int(x::xs) : int list = x :: unzip_single_int(xs) fun unzip_single_string[] : string list = [] | unzip_single_string(x::xs) : string list = x :: unzip_single_string(xs) fun unzip[] : (int list * string list) = ([], []) | unzip([twopls]) : (int

问题 Update: What I want to do with this code is to get a list of dates, year/month/day and a given number as a month, and check to see how many of the dates in the given list are in the same month as that given month. What I meant of x = x + 1 was x++ such as in java or C or C#. As the output I want x. if there is no match, 0 and for any match x = x + 1 So this is my code, fun number_in_month (Dlist : (int * int * int) list, Month : int, x : int) = if null Dlist then x else if #2 (hd Dlist) =

问题 I'm completely new to SML and I have no idea how to work with anything related to it. I am supposed to use the SMLNJ compiler and I'm currently coding using Notepad++. But how do I compile the program exactly? Do I copy and paste the code in the SMLNJ command line thing? Or is there an environment for SMLNJ I can actually code in and compile my code? PLEASE HELP! 回答1: If by "compile" you mean "compile to a stand-alone executable" -- don't worry about that when first learning the language as a

问题 I found this code on another SO post: fun number_in_month ([], _) = 0 | number_in_month ((_,x2,_) :: xs, m) = if x2 = m then 1 + number_in_month(xs, m) else number_in_month(xs, m) and to my surprise it works. - number_in_month ([(2018,1,1),(2018,2,2),(2018,2,3),(2018,3,4),(2018,2,30)],2); val it = 3 : int My confusion is first unfamiliarity with this form of classic mathematical recursive function (I'm a beginner), then how it actually steps through the list. My intuition would have the

问题 this is homework from the ProgLang course at Coursera but the due date has passed and I'm only auditing this. This is a really cheap problem but it looks like I can't do this in SML. Given a list of date 3-tuples of int and an int, return how often that int matches #2 of the tuple (the month). At first I had a lot of [tycon mismatch] and then played around with the function header. I have no idea how to denote a list of tuples, prolly all down to that. fun number_in_month (date : [int*int*int

问题 How can you generate a random number from a specific range, for example the integer 34 in the range [1, 100]? I looked at the Random structure but it doesn't give me what I want, at least from what I can understand. 回答1: I think you have to use the Random structure in the given link like this ... - val nextInt = Random.randRange (1,100); - val r = Random.rand (1,1); - val x1 = nextInt r; - val x2 = nextInt r; 回答2: To get 34 integers between 1 and 100, you could use: let val seed = Random.rand