mlyacc/examples/fol/fol.lex

   1 structure Tokens = Tokens
   2 structure Interface = Interface
   3 open Interface
   4
   5 type pos = Interface.pos
   6 type svalue = Tokens.svalue
   7 type ('a,'b) token = ('a,'b) Tokens.token
   8 type lexresult= (svalue,pos) token
   9
  10 val eof = fn () => Tokens.EOF(!line,!line)
  11 fun makeInt (s : string) = s
  12
  13 %%
  14 %header (functor FolLexFun(structure Tokens: Fol_TOKENS
  15                            structure Interface: INTERFACE) : LEXER);
  16 lcstart=[a-z!&$+/<=>?@~|#*`]|\-;
  17 ucstart=[A-Z_];
  18 idchars={lcstart}|{ucstart}|[0-9];
  19 lcid={lcstart}{idchars}*;
  20 ucid={ucstart}{idchars}*;
  21 ws=[\t\ ]*;
  22 num=[0-9]+;
  23 %%
  24 <INITIAL>{ws}   => (lex());
  25 <INITIAL>\n     => (next_line(); lex());
  26 <INITIAL>":-"   => (Tokens.BACKARROW(!line,!line));
  27 <INITIAL>","    => (Tokens.COMMA(!line,!line));
  28 <INITIAL>";"    => (Tokens.SEMICOLON(!line,!line));
  29 <INITIAL>"."    => (Tokens.DOT(!line,!line));
  30 <INITIAL>"("    => (Tokens.LPAREN(!line,!line));
  31 <INITIAL>")"    => (Tokens.RPAREN(!line,!line));
  32 <INITIAL>"->"   => (Tokens.ARROW(!line,!line));
  33 <INITIAL>"=>"   => (Tokens.DOUBLEARROW(!line,!line));
  34 <INITIAL>"|"    => (Tokens.BAR(!line,!line));
  35 <INITIAL>"true" => (Tokens.TRUE(!line,!line));
  36 <INITIAL>"forall" => (Tokens.FORALL(!line,!line));
  37 <INITIAL>"exists" => (Tokens.EXISTS(!line,!line));
  38 <INITIAL>{lcid} => (Tokens.LCID (yytext,!line,!line));
  39 <INITIAL>{ucid} => (Tokens.UCID (yytext,!line,!line));
  40 <INITIAL>{num}  => (Tokens.INT (makeInt yytext,!line,!line));
  41 <INITIAL>.      => (error ("ignoring illegal character" ^ yytext,
  42                            !line,!line); lex());