test17.txt

*************** Source File ****************

(* In this program the explode is called funlist in the CoCo virtual machine
   while the implode is called concat in the virtual machine. Unlike SML, 
   explode returns a list of strings and implode concatenates a list of strings
   to build a string.
*)

let fun skipH nil = ()
      | skipH ("H"::t) = skipH t
      | skipH (h::t) = 
        (println h;
         skipH t)
    val s = input("Please enter some text: ")
in
  skipH (explode s);
  println (implode (explode s))
end

******************* AST ********************
letdec(
   funmatches([
   funmatch('skipH',[
      match(idpat('nil')      ,tuplecon([])      )      ,      match(infixpat('::',strpat('"H"'),idpat('t'))      ,apply(id('skipH'),id('t'))      )      ,      match(infixpat('::',idpat('h'),idpat('t'))      ,      expsequence([
apply(id('println'),id('h'))         ,apply(id('skipH'),id('t'))      ])
      )   ])
   ])
,
   [
    letdec(
       bindval(idpat('s'),apply(id('input'),str('"Please enter some text: "'))),
       [
apply(id('skipH'),apply(id('explode'),id('s')))        ,apply(id('println'),apply(id('implode'),apply(id('explode'),id('s'))))
       ])

   ])
.
************* Type Checking ****************
Typechecking is commencing...
Here is the AST
letdec(funmatches([funmatch(skipH,[match(idpat(nil),tuplecon([])),match(infixpat(::,strpat("H"),idpat(t)),apply(id(skipH),id(t))),match(infixpat(::,idpat(h),idpat(t)),expsequence([apply(id(println),id(h)),apply(id(skipH),id(t))]))])]),[letdec(bindval(idpat(s),apply(id(input),str("Please enter some text: "))),[apply(id(skipH),apply(id(explode),id(s))),apply(id(println),apply(id(implode),apply(id(explode),id(s))))])])


val skipH = fn : str list -> unit
val s : str


val it : unit

The program passed the typechecker.
********* Target Program Execution *********
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