sml
galaxy-gfisher[1]: Standard ML of New Jersey, Version 0.93, February 15, 1993
val it = () : unit
-
- (* CHAPTERS 1 AND 5: SIMPLE EXPRESSIOS AND FUNCTIONS *)
-
- 2+2;
val it = 4 : int
- fun TwoPlusTwo() = 2+2;
val TwoPlusTwo = fn : unit -> int
- TwoPlusTwo();
val it = 4 : int
- TwoPlusTwo;
val it = fn : unit -> int
- fun XPlusTwo(x) = x+2;
val XPlusTwo = fn : int -> int
- XPlusTwo(2);
val it = 4 : int
- fun XPlusY(x,y) = x+y;
std_in:8.20 Error: overloaded variable cannot be resolved: +
- fun XPlusY(x,y: int) = x+y;
val XPlusY = fn : int * int -> int
- XPlusY(2,2);
val it = 4 : int
- fun XPlusY(x: int, y) = x+y;
val XPlusY = fn : int * int -> int
- XPlusY(2,2);
val it = 4 : int
- val XPlusY = fn(x,y: int) => x+y;
val XPlusY = fn : int * int -> int
- XPlusY(2,2);
val it = 4 : int
- val s = "xyz";
val s = "xyz" : string
- val r = 2.5;
val r = 2.5 : real
- "Hello " ^ "world.";
val it = "Hello world." : string
- "xyz" < "abc";
val it = false : bool
- (1<2) or (2<1);
std_in:23.7-23.8 Error: unbound variable or constructor: or
std_in:23.1-23.14 Error: operator is not a function
operator: bool
in expression:
(< : overloaded (1,2)) bogus
- (1<2) orelse (2<1);
val it = true : bool
- (1<2) andalso (2<1);
val it = false : bool
- if (1<2) then "yes" else "no";
val it = "yes" : string
- if (1<2) then "yes";
= ;
std_in:32.20 Error: syntax error found at SEMICOLON
-
- (* CHAPTER 2: TYPE CONSISTENCY *)
-
- 2.5/2;
std_in:0.0-0.0 Error: operator and operand don't agree (tycon mismatch)
operator domain: real * real
operand: real * int
in expression:
/ (2.5,2)
- truncate(2.5)/2;
std_in:0.0-0.0 Error: operator and operand don't agree (tycon mismatch)
operator domain: real * real
operand: int * int
in expression:
/ (truncate (2.5),2)
- 2 div 2;
val it = 1 : int
- 2.5 / real(2);
val it = 1.25 : real
- if 1=1 then 1 else 2.5;
std_in:35.1-35.22 Error: rules don't agree (tycon mismatch)
expected: bool -> int
found: bool -> real
rule:
false => 2.5
- if 1 then 2 else 3;
std_in:0.0-0.0 Error: case object and rules don't agree (tycon mismatch)
rule domain: bool
object: int
in expression:
(case 1
of true => 2
| false => 3)
-
- (* CHAPTER 3: VARIABLES AND ENVIRONMENTS *)
-
- val var1 = 10;
val var1 = 10 : int
- var2 = 20;
std_in:0.0-0.0 Error: unbound variable or constructor: var2;
- val Var1 = 10;
val Var1 = 10 : int
- val Var' = 10;
val Var' = 10 : int
- val x = 10;
val x = 10 : int
- fun f() = x;
val f = fn : unit -> int
- f();
val it = 10 : int
- val x = 20;
val x = 20 : int
- f();
val it = 10 : int
-
- (* CHAPTER 4: TUPLES AND LISTS *)
-
- val t = (1, 2.5, "three");
val t = (1,2.5,"three") : int * real * string
- val tn = (1, 2.5, ("three", true));
val tn = (1,2.5,("three",true)) : int * real * (string * bool)
- val t1 = (1);
val t1 = 1 : int
- #1(t);
val it = 1 : int
- #2(t);
val it = 2.5 : real
- #4(t);
std_in:62.1-62.5 Error: operator and operand don't agree (record labels)
operator domain: {4:'Y, '...Z}
operand: int * real * string
in expression:
(fn {4=4,...} => 4) (t)
- val l = [1,2,3,4];
val l = [1,2,3,4] : int list
- hd(l);
val it = 1 : int
- tl(l);
val it = [2,3,4] : int list
- 0::l;
val it = [0,1,2,3,4] : int list
- l;
val it = [1,2,3,4] : int list
- l@[5,6];
val it = [1,2,3,4,5,6] : int list
- l;
val it = [1,2,3,4] : int list
- 1::nil;
val it = [1] : int list
- 1::2::3::nil;
val it = [1,2,3] : int list
- ["1",2,3];
std_in:73.1-73.9 Error: operator and operand don't agree (tycon mismatch)
operator domain: string * string list
operand: string * int list
in expression:
"1" :: 2 :: 3 :: nil
-
- explode("abc");
val it = ["a","b","c"] : string list
- implode(explode("abc"));
val it = "abc" : string
-
- val nl = [1,2,3,[4,5],6];
std_in:77.10-77.24 Error: operator and operand don't agree (tycon mismatch)
operator domain: int list * int list list
operand: int list * int list
in expression:
(4 :: 5 :: nil) :: 6 :: nil
-
- (* CHAPTER 5: MORE ON FUNCTIONS *)
-
- fun reverse(L) =
= if L = nil then nil
= else reverse(tl(L)) @ [hd(L)];
val reverse = fn : ''a list -> ''a list
- reverse(l);
val it = [4,3,2,1] : int list
-
- (* CHAPTER 6: PATTERNS IN FUNCTION DEFINITIONS *)
-
- fun reverse(nil) = nil
= | reverse(x::xs) = reverse(xs) @ [x];
val reverse = fn : 'a list -> 'a list
- reverse(l);
val it = [4,3,2,1] : int list (* SEE FIGURE 6.1 ON PAGE 51 *)
-
- fun sumLists(nil) = 0
= | sumLists(nil::YS) = sumLists(YS)
= | sumLists((x::xs)::YS) = x + sumLists(xs::YS);
val sumLists = fn : int list list -> int
- fun sumLists2(ll) =
= if ll = nil then 0
= else if hd(ll) = nil then sumLists2(tl(ll))
= else hd(hd(ll)) + sumLists2(tl(hd(ll)) :: tl(ll));
val sumLists2 = fn : int list list -> int
- val ll = [[1,2], nil, [3], [4,5,6]];
val ll = [[1,2],[],[3],[4,5,6]] : int list list
- sumLists(ll);
val it = 21 : int
- sumLists2(ll);
val it = 21 : int
- fun sumLists(nil) = 0
= | sumLists(nil::YS) = sumLists(YS)
= | sumLists(x::xs::YS) = x + sumLists(xs::YS);
std_in:56.27-56.46 Error: operator and operand don't agree (tycon mismatch)
operator domain: 'Z list * 'Z list
operand: 'Z list * int
in expression:
+ : overloaded (x,sumLists (<exp> <exp>))
std_in:56.29 Error: overloaded variable not defined at type
symbol: +
type: 'Z list
-
- (* CHAPTER 7: LET *)
-
- fun hundredthPower(x:real) =
= let
= val four = x*x*x*x;
= val twenty = four*four*four*four*four;
= in
= twenty*twenty*twenty*twenty*twenty
= end;
val hundredthPower = fn : real -> real
- hundredthPower(1.00001);
val it = 1.00100049516174 : real
- fun hundredthPower(x:real) =
= let
= val x = x*x*x*x;
= val x = x*x*x*x*x
= in
= x*x*x*x*x
= end;
val hundredthPower = fn : real -> real
- hundredthPower(1.00001);
val it = 1.00100049516174 : real
-
- fun split(nil) = (nil,nil)
= | split([a]) = ([a],nil)
= | split(a::b::cs) =
= let
= val (M,N) = split(cs)
= in
= (a::M, b::N)
= end;
val split = fn : 'a list -> 'a list * 'a list
- split([1,2,3,4,5]);
val it = ([1,3,5],[2,4]) : int list * int list
- fun merge(nil,M) = M
= | merge(L,nil) = L
= | merge(L as x::xs, M as y::ys) =
= if (x:int)<y then x::merge(xs,M)
= else y::merge(L,ys);
val merge = fn : int list * int list -> int list
- merge([1,2,3],[4,5]);
val it = [1,2,3,4,5] : int list
- fun mergeSort(nil) = nil
= | mergeSort([a]) = [a]
= | mergeSort(L) =
= let
= val (M,N) = split(L);
= val M = mergeSort(M);
= val N = mergeSort(N);
= in
= merge(M,N)
= end;
val mergeSort = fn : int list -> int list
- mergeSort([5,4,3,2,1]);
val it = [1,2,3,4,5] : int list
-
- (* CHAPTER 9: INPUT/OUTPUT *)
-
- fun printList(nil) = ()
= | printList(x::xs) =
= (print(x:int); print("\n"); printList(xs));
val printList = fn : int list -> unit
- printList([1,2,3]);
1
2
3
val it = () : unit
- fun readList(file) =
= if end_of_stream(file) then nil
= else input(file,1) :: readList(file);
val readList = fn : instream -> string list
- readList(open_in("test.dat"));
val it = ["1","2","\n","a","b","\n"] : string list
-
- (* CHAPTER 12: TYPES AND DATATYPES *)
-
- type vector = real list;
type vector = real list
- val v = [1.0, 2.0] : vector;
val v = [1.0,2.0] : vector
- val w = [1.0, 2.0];
val w = [1.0,2.0] : real list
- v=w;
val it = true : bool
-
- datatype fruit = Apple | Pear | Grape;
datatype fruit
con Apple : fruit
con Grape : fruit
con Pear : fruit
- fun isApple(x) = (x=Apple);
val isApple = fn : fruit -> bool
-
- datatype intOrReal =
= IntVal of int |
= RealVal of real;
datatype intOrReal
con IntVal : int -> intOrReal
con RealVal : real -> intOrReal
-
- datatype intOrRealOrStringOrListOfSame =
= I of int |
= R of real |
= S of string |
= L of intOrRealOrStringOrListOfSame list;
datatype intOrRealOrStringOrListOfSame
con I : int -> intOrRealOrStringOrListOfSame
con L : intOrRealOrStringOrListOfSame list -> intOrRealOrStringOrListOfSame
con R : real -> intOrRealOrStringOrListOfSame
con S : string -> intOrRealOrStringOrListOfSame
- val mixedList = L[I(10), R(2.5), S("xyz"), L[I(20), R(5.0)]];
val mixedList = L [I 10,R 2.5,S "xyz",L [I #,R #]]
: intOrRealOrStringOrListOfSame
-