Commit fa20d474 authored by Pietro Abate's avatar Pietro Abate
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[r2003-07-29 14:33:46 by cvscast] Empty log message

Original author: cvscast
Date: 2003-07-29 14:33:46+00:00
parent 87f9b98a
...@@ -362,23 +362,15 @@ let [x] = bold [doc] in print_xml x;; ...@@ -362,23 +362,15 @@ let [x] = bold [doc] in print_xml x;;
let stack = ref [Int*] [] let stack = ref [Int*] []
let fun push(x : Int) : [] = let fun push(x : Int) : [] =
stack := [x !!stack] stack := [x ; !stack]
let fun pop ([] : []) : Int = let fun pop ([] : []) : Int =
match !stack with [x ;y] -> stack := y; x | _ -> raise \"Empty stack\" match !stack with [x ; y] -> stack := y; x | _ -> raise \"Empty stack\"
(* In a pattern [ ... ; y] the variable y captures the tail of the *)
(* In [ pattern ;y] the variable y captures the rest of the *) (* sequence. It is equivalent to [ ... y::_*]. *)
(* sequence. It is equivalent to [pattern y::_*] *) (* In an expression [ ... ; e ] the expression e denotes the tail *)
(* *) (* of the sequence. It is equivalent to [ ... ] @ e *)
(* Since sequences are encoded by pairs, we could write *)
(* the following [deprecated] equivalent definitions *)
(*
let fun push(x : Int) : [] =
stack := (x, !stack)
let fun pop ([] : []) : Int =
match !stack with (x, y) -> stack := y; x | _ -> raise \"Empty stack\"
*)
;; ;;
......
(* In CDuce the expression "ref T exp" returns a reference *) (* In CDuce the expression "ref T exp" returns a reference *)
(* to the result of "exp" and has type "ref T" provided that *) (* to the result of "exp" and has type "ref T" provided that *)
(* "exp" is of type "T" *) (* "exp" is of type "T". References come equipped with three *)
(* operators: ":=" (assignment), "!" (dereferencing), and ";"*)
(* (sequencing). *)
let stack = ref [Int*] []
(* References come equipped with three operators: ":=" *) let stack = ref [Int*] []
(* (assignment), "!" (dereferencing), ";" (sequencing) *)
let fun push(x : Int) : [] = let fun push(x : Int) : [] =
stack := [x; !stack] stack := [x; !stack]
...@@ -13,10 +13,12 @@ let fun push(x : Int) : [] = ...@@ -13,10 +13,12 @@ let fun push(x : Int) : [] =
let fun pop ([] : []) : Int = let fun pop ([] : []) : Int =
match !stack with [x; y] -> stack := y; x | _ -> raise "Empty stack" match !stack with [x; y] -> stack := y; x | _ -> raise "Empty stack"
(* In a pattern [ ... ; y] the variable y captures the rest of the *)
(* In a pattern [ ... ; y] the variable y captures the tail of the *)
(* sequence. It is equivalent to [ ... y::_*]. *) (* sequence. It is equivalent to [ ... y::_*]. *)
(* In an expression [ ... ; e ] the expression e denote the tail of*) (* In an expression [ ... ; e ] the expression e denotes the tail *)
(* the sequence. It is equivaent to [ ... ] @ y *) (* of the sequence. It is equivalent to [ ... ] @ e *)
;; ;;
......
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