1 / 0;;
List.hd [] ;;
exception Our_int_exception of int;;
Our_int_exception 5;;
Failure "hey";;
raise (Failure "hey");;
List.hd;;
let hd = fun l -> match l with \n                        [] -> raise (Failure "our hd failed for []")\n                      | a::ll -> a;;
hd [1;2;3;4];;
hd [];;
let hd = fun l -> match l with \n                        [] -> raise (Our_int_exception 3)\n                      | a::ll -> a;;
hd [];;
try 1 / 0 with\n                 Division_by_zero -> 0\n               | Our_int_exception n -> n\n               | Failure s -> -1;;
1/0;;
try hd [] with Division_by_zero -> 0 | Failure s -> 1;;
try hd [] with Division_by_zero -> 0 | Failure s -> 1 | Our_int_exception n -> n;;
();;
5;;
print_string("a\\n");;
print_string("a\\n"); 5;;
5;;
6; 5;;
[|0;1;2;3|];;
[|0;1;2;3|].(2);;
[|0;10;20;30|].(2);;
[|0;1;2;3|].(2) <- 200;;
let a = [|0;1;2;3|].(2) <- 200;;
a;;
let a = [|0;1;2;3|];;
let a.(2) <- 200;;
a.(2) <- 200;;
let a = [|0;1;2;3|];;
a.(2) <- 200;;
a;;
let f v i j = let temp = v.(i); v.(i) <- v.(j); v.(j) <- temp;;
let f v i j = (let temp = v.(i); v.(i) <- v.(j); v.(j) <- temp);;
let f v i j = let temp = v.(i) in (v.(i) <- v.(j); v.(j) <- temp);;
let swap v i j = let temp = v.(i) in (v.(i) <- v.(j); v.(j) <- temp);;
swap [|0;1;2;3|] 2 3;;
let a = [|0;1;2;3|];;
swap a 2 3;;
a;;
type mpoint = {mutable x:float; mutable y: float};;
let move = fun ((dx, dy), p) -> p.x <- p.x +. dx; p.y <- p.y +. dy;;
let p = {x=1.; y=2.};;
move ((1., 1.), p);;
p;;
let mp1 = {x = 1.; y=2.};;
let mp2 = {x = 1.; y=2.};;
mp1=mp2;;
mp1==mp2;;
mp1;;
mp2;;
let mp3 = mp1;;
move ((10., 10.) mp1);;
move ((10., 10.), mp1);;
mp1;;
mp3;;
mp2;;
let mp2 = {x = 1.; y=2.};;
let x=5;;
let y=5;;
x==y;;
mp3=mp1;;
mp1=mp2;;
let mp1 = {x = 1.; y=2.};;
let mp2 = {x = 1.; y=2.};;
mp1;;
mp2;;
mp1=mp2;;
mp1==mp2;;
ref;;
let c = ref 0;;
c;;
!c;;
let l = [ref 1; ref 2; ref 3];;
List.hd(1);;
List.hd(l);;
!List.hd(l);;
!(List.hd(l));;
c;;
c:=5;;
c;;
!c;;
let c = ref 0;;
c := 5;;
c;;
let gensym = let counter = ref 0 in (fun () -> counter := !counter + 1; "sym"^(string_of_int !counter));;
let gensym = let counter = ref 0 in fun () -> (counter := !counter + 1; "sym"^(string_of_int !counter));;
gensym();;
let gensym = let counter = ref 0 in fun () -> (counter := !counter + 1; "sym"^(string_of_int !counter));;
gensym();;
let gensym = let counter = ref 0 in fun () -> (counter := !counter + 1; "sym"^(string_of_int !counter));;
module type LIST_STACK = sig\n  (** [Empty] is raised when an operation cannot be applied\n      to an empty stack. *)\n  exception Empty\n\n  (** [empty] is the empty stack. *)\n  val empty : 'a list\n\n  (** [is_empty s] is whether [s] is empty. *)\n  val is_empty : 'a list -> bool\n\n  (** [push x s] pushes [x] onto the top of [s]. *)\n  val push : 'a -> 'a list -> 'a list\n\n  (** [peek s] is the top element of [s].\n      Raises [Empty] if [s] is empty. *)\n  val peek : 'a list -> 'a\n\n  (** [pop s] is all but the top element of [s].\n      Raises [Empty] if [s] is empty. *)\n  val pop : 'a list -> 'a list\nend;;
module ListStack : LIST_STACK = struct\n  let empty = []\n\n  let is_empty = function [] -> true | _ -> false\n\n  let push x s = x :: s\n\n  exception Empty\n\n  let peek = function\n    | [] -> raise Empty\n    | x :: _ -> x\n\n  let pop = function\n    | [] -> raise Empty\n    | _ :: s -> s\nend;;
ListStack.push 2 (ListStack.push 1 ListStack.empty);;
ListStack.(push 2 (push 1 empty));;
module type LIST_STACK = sig\n  (** [Empty] is raised when an operation cannot be applied\n      to an empty stack. *)\n  exception Empty\n\n  (** [empty] is the empty stack. *)\n  val empty : 'a list\n\n  (** [is_empty s] is whether [s] is empty. *)\n  val is_empty : 'a list -> bool\n\n  (** [push x s] pushes [x] onto the top of [s]. *)\n  val push : 'a -> 'a list -> 'a list\n\n  (** [peek s] is the top element of [s].\n      Raises [Empty] if [s] is empty. *)\n  val peek : 'a list -> 'a\n\n  (** [pop s] is all but the top element of [s].\n      Raises [Empty] if [s] is empty. *)\n  val pop : 'a list -> 'a list\nend;;
module type LIST_STACK = sig\n  (** [Empty] is raised when an operation cannot be applied\n      to an empty stack. *)\n\n  (** [empty] is the empty stack. *)\n  val empty : 'a list\n\n  (** [is_empty s] is whether [s] is empty. *)\n  val is_empty : 'a list -> bool\n\n  (** [push x s] pushes [x] onto the top of [s]. *)\n  val push : 'a -> 'a list -> 'a list\n\n  (** [peek s] is the top element of [s].\n      Raises [Empty] if [s] is empty. *)\n  val peek : 'a list -> 'a\n\n  (** [pop s] is all but the top element of [s].\n      Raises [Empty] if [s] is empty. *)\n  val pop : 'a list -> 'a list\nend;;
module ListStack : LIST_STACK = struct\n  let empty = []\n\n  let is_empty = function [] -> true | _ -> false\n\n  let push x s = x :: s\n\n  exception Empty\n\n  let peek = function\n    | [] -> raise Empty\n    | x :: _ -> x\n\n  let pop = function\n    | [] -> raise Empty\n    | _ :: s -> s\nend;;
ListStack.pop [];;
try ListStack.pop [] with ListStack.Empty -> [];;
module type LIST_STACK = sig\n  (** [Empty] is raised when an operation cannot be applied\n      to an empty stack. *)\n  exception Empty\n\n  (** [empty] is the empty stack. *)\n  val empty : 'a list\n\n  (** [is_empty s] is whether [s] is empty. *)\n  val is_empty : 'a list -> bool\n\n  (** [push x s] pushes [x] onto the top of [s]. *)\n  val push : 'a -> 'a list -> 'a list\n\n  (** [peek s] is the top element of [s].\n      Raises [Empty] if [s] is empty. *)\n  val peek : 'a list -> 'a\n\n  (** [pop s] is all but the top element of [s].\n      Raises [Empty] if [s] is empty. *)\n  val pop : 'a list -> 'a list\nend;;
module ListStack : LIST_STACK = struct\n  let empty = []\n\n  let is_empty = function [] -> true | _ -> false\n\n  let push x s = x :: s\n\n  exception Empty\n\n  let peek = function\n    | [] -> raise Empty\n    | x :: _ -> x\n\n  let pop = function\n    | [] -> raise Empty\n    | _ :: s -> s\nend;;
try ListStack.pop [] with ListStack.Empty -> [];;
module type LIST_STACK = sig\n  (** [Empty] is raised when an operation cannot be applied\n      to an empty stack. *)\n  exception Empty\n\n  (** [empty] is the empty stack. *)\n  val empty : 'a list\n\n  (** [is_empty s] is whether [s] is empty. *)\n  val is_empty : 'a list -> bool\n\n  (** [push x s] pushes [x] onto the top of [s]. *)\n  val push : 'a -> 'a list -> 'a list\n\n  (** [peek s] is the top element of [s].\n      Raises [Empty] if [s] is empty. *)\n  val peek : 'a list -> 'a\nend;;
module type LIST_STACK = sig\n  (** [Empty] is raised when an operation cannot be applied\n      to an empty stack. *)\n  exception Empty\n\n  (** [empty] is the empty stack. *)\n  val empty : 'a list\n\n  (** [is_empty s] is whether [s] is empty. *)\n  val is_empty : 'a list -> bool\n\n  (** [push x s] pushes [x] onto the top of [s]. *)\n  val push : 'a -> 'a list -> 'a list\n\n  (** [peek s] is the top element of [s].\n      Raises [Empty] if [s] is empty. *)\n  val peek : 'a list -> 'a\n\n  (** [pop s] is all but the top element of [s].\n      Raises [Empty] if [s] is empty. *)\n  val pop : 'a list -> 'a list\nend;;
module ListStack : LIST_STACK = struct\n  let empty = []\n\n  let is_empty = function [] -> true | _ -> false\n\n  let push x s = x :: s\n\n  exception Empty\n\n  let peek = function\n    | [] -> raise Empty\n    | x :: _ -> x\nend;;
module type LIST_STACK = sig\n  (** [Empty] is raised when an operation cannot be applied\n      to an empty stack. *)\n  exception Empty\n\n  (** [empty] is the empty stack. *)\n  val empty : 'a list\n\n  (** [is_empty s] is whether [s] is empty. *)\n  val is_empty : 'a list -> bool\n\n  (** [push x s] pushes [x] onto the top of [s]. *)\n  val push : 'a -> 'a list -> 'a list\n\n  (** [peek s] is the top element of [s].\n      Raises [Empty] if [s] is empty. *)\n  val peek : 'a list -> 'a\n\n  (** [pop s] is all but the top element of [s].\n      Raises [Empty] if [s] is empty. *)\n  val pop : 'a list -> 'a list\nend;;
module ListStack : LIST_STACK = struct\n  let empty = []\n\n  let is_empty = function [] -> true | _ -> false\n\n  let push x s = x :: s\n\n  exception Empty\n\n  let peek = function\n    | [] -> raise Empty\n    | x :: _ -> x\n\n  let pop = function\n    | [] -> raise Empty\n    | _ :: s -> s\n\n  let internal = function | [] -> [] | _ -> [];;\nend;;
ListStack.internal;;
ListStack.pop;;