possibility to use other symbols preceded by `

Author: pierre.hyvernat

NFA.ml

@@ -147,7 +147,9 @@ module type NFAType = sig
     val from_dfa : dfa -> nfa
     val to_dfa : nfa -> dfa
 (*
-    val reachable : nfa -> nfa
+ *  TODO
+    val accessible : nfa -> nfa
+    val co_accessible : nfa -> nfa
     val remove_epsilon : nfa -> nfa
 *)
 end

lexer.mll

@@ -2,11 +2,14 @@
 open Parser
 
 let get_string s = String.sub s 1 ((String.length s) - 2)
+let get_symbol s = String.sub s 1 ((String.length s) - 1)
 let get_index s = String.sub s 3 ((String.length s) - 3)
 let get_state_index s = String.sub s 1 ((String.length s) - 1)
 }
-let symbol = [ 'a'-'z' ]
-let str = '"' symbol* '"'
+let lower_symbol = [ 'a'-'z' ]
+let character =  [ 'a'-'z' 'A'-'Z' '0'-'9' '.' ',' ]
+let symbol = "`" character
+let str = '"' character* '"'
 let reg = "REG" [ '0'-'9' ]+
 let dfa = "DFA" [ '0'-'9' ]+
 let nfa = "NFA" [ '0'-'9' ]+
@@ -24,7 +27,8 @@ rule token = parse
   | '*'             { STAR }
   | '0'             { ZERO }
   | '1'             { ONE }
-  | symbol          { SYMB(Lexing.lexeme_char lexbuf 0) }
+  | lower_symbol    { SYMB(Lexing.lexeme_char lexbuf 0) }
+  | symbol          { SYMB((Lexing.lexeme lexbuf).[1]) }
 
   | ','             { COMMA }
   | str             { STR(get_string (Lexing.lexeme lexbuf)) }

prof.ml

@@ -4,7 +4,7 @@ let concat_n s n =
 
 let main () =
     let n = 64 in
-    let cmd = "\"" ^ (concat_n "a" n) ^ "\" ~ " ^ (concat_n "(1+a)" n) ^ (concat_n "a" n) in
+    let cmd = "\"" ^ (concat_n "a" n) ^ "\" < " ^ (concat_n "(1+a)" n) ^ (concat_n "a" n) in
     print_endline cmd;
     let lexbuf = Lexing.from_string (cmd^"\n") in
         Parser.toplevel Lexer.token lexbuf

regexp.ml

@@ -33,7 +33,10 @@ type regexp =
 let rec string_of_regexp (r:regexp) : string = match r with
     | Zero -> "0"
     | One -> "1"
-    | Symb(a) -> String.make 1 a
+    | Symb(a) ->
+            if String.contains "abcdefghijklmnopqrstuvwxyz" a
+            then String.make 1 a
+            else "`" ^ String.make 1 a
     | Star(Zero as r) | Star(One as r) | Star(Symb(_) as r) ->
             (string_of_regexp r) ^ "*"
     | Star(r) -> "(" ^ (string_of_regexp r) ^ ")*"

tests/binary_three.mlr

@@ -1,17 +1,16 @@
-{- automaton checking if a binary number is divisible by 3,
-   where o means 0 and l means 1 -}
+{- automaton checking if a binary number is divisible by 3 -}
 
 NFA1 :=
-            |   _   o   l
+            |   _   `0  `1
 ---------------------------
 -> s1 ->    |   !   s1  s2
    s2       |   !   s3  s1
    s3       |   !   s2  s3
 
 REG1 := < NFA1 >
 
-:assert "ll" < REG1
-:assert "llo" < REG1
-:assert "lool" < REG1
-:assert NOT "lolo" < REG1
+:assert "11" < REG1
+:assert "110" < REG1
+:assert "1001" < REG1
+:assert NOT "1010" < REG1