Sources du TP Menhir

tp/tp-menhir/code/AST.ml

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+type exp =
+  | Id of identifier
+  | LInt of int
+  | Add of exp * exp
+  | Mul of exp * exp
+  | Sum of identifier * exp * exp * exp
+
+and identifier = string

tp/tp-menhir/code/Makefile

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+.PHONY: all clean
+
+all:
+	dune build marthe.exe
+	ln -sf _build/default/marthe.exe marthe
+
+clean:
+	dune clean
+	rm -fr *~ marthe

tp/tp-menhir/code/dune

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+(ocamllex lexer)
+
+(menhir
+ (flags --explain --inspection --table)
+ (modules parser))
+
+(executable
+ (name marthe)
+ (ocamlopt_flags :standard)
+ (libraries menhirLib)
+)

tp/tp-menhir/code/dune-project

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+(lang dune 1.4)
+(using menhir 2.0)

tp/tp-menhir/code/lexer.mll

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+{ (* Emacs, open this file with -*- tuareg -*- *)
+  open Parser
+}
+
+let layout = ' ' | '\t' | '\n'
+let number = ['0'-'9']+
+let identifier = ['a'-'z']['A'-'Z' '0'-'9' 'a'-'z' '_']*
+
+rule token = parse
+| eof             { EOF }
+| layout          { token lexbuf }
+| number as i     { INT (int_of_string i) }
+| identifier as s { ID s }
+| "+"             { PLUS }
+| _ as c {
+  failwith (Printf.sprintf "Invalid character: %c\n" c)
+}

tp/tp-menhir/code/marthe.ml

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+let rec interactive_loop () =
+  welcome_message ();
+  let rec loop () =
+    begin try
+      read () |> eval |> print
+    with exn ->
+      Printf.printf "Error: %s\n%!" (Printexc.to_string exn)
+    end;
+    loop ()
+  in
+  loop ()
+
+and welcome_message () =
+  Printf.printf "
+  ====================================================\n
+   Welcome to the incredible Marthe interactive loop! \n
+  ====================================================\n
+"
+
+and read () =
+  invite (); input_line stdin |> parse
+
+and invite () =
+  Printf.printf "> %!"
+
+and parse input =
+  let lexbuf = Lexing.from_string input in
+  Parser.phrase Lexer.token lexbuf
+
+and print e =
+  Printf.printf ":- %s\n%!" (Printer.string_of_exp e)
+
+and eval e =
+  e
+
+let main = interactive_loop ()

tp/tp-menhir/code/parser.mly

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+%{ (* Emacs, open this with -*- tuareg -*- *)
+open AST
+%}
+
+%token<int> INT
+%token<string> ID
+%token PLUS EOF
+
+%start<AST.exp> phrase
+
+%left PLUS
+
+%%
+
+phrase: e=exp EOF
+{
+  e
+}
+
+exp: x=INT
+{
+  LInt x
+}
+| x=ID
+{
+  Id x
+}
+| e1=exp PLUS e2=exp
+{
+  Add (e1, e2)
+}

tp/tp-menhir/code/printer.ml

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+open AST
+
+let string_of_exp e =
+  let rec aux = function
+    | Id x ->
+       x
+    | LInt x ->
+       string_of_int x
+    | Add (e1, e2) ->
+       Printf.sprintf "(%s + %s)" (aux e1) (aux e2)
+    | Mul (e1, e2) ->
+       Printf.sprintf "(%s * %s)" (aux e1) (aux e2)
+    | Sum (x, start, stop, exp) ->
+       Printf.sprintf "sum(%s, %s, %s, %s)"
+         x (aux start) (aux stop) (aux exp)
+  in
+  aux e