load lex ;    /* See the file 'lex.wrk' in the aiTRAN library. */

/* One fully worked example:
   Producing lex info for C numeric constants */


dcl Tkn_cmt : lex ;

dcl Val_oct, Val_int, Val_hex, Val_flt : lex ;


say Tkn_cmt <== LIT("/*") <&>
                OPT(SOM(NAY("*") <|> (ANY("*") <&> NAY("/"))))
                <&>
                LIT("*/") ;


say Val_oct <== ANY("0") <&> SPN('0'---'7') <&>
                   OPT(ANY("Ll")) ;

say Val_int <== SPN('0'---'9') <&> OPT(ANY("Ll")) ;

say Val_hex <== ANY("0") <&>
                ANY("Xx") <&> SPN('0'---'9'<>
                                  'a'---'f'<>
                                  'A'---'F') <&> OPT(ANY("Ll")) ;


say Val_flt <== let dex === SPN ( '0' --- '9' ) in
                let dot === ANY(".") in

   let num33 ===  dot <&> dex in
   let num34 ===  dot <&> dex <&> ANY("Ee") in
   let num36 ===  dot <&> dex <&> ANY("Ee")
                  <&> dex in
   let num38 ===  dot <&> dex <&> ANY("Ee")
                  <&> ANY("+-") <&> dex in

   let num11 ===  dex <&> ANY("Ee") in
   let num13 ===  dex <&> ANY("Ee") <&> dex in
   let num15 ===  dex <&> ANY("Ee") <&> ANY("+-") <
                  &> dex in

   let num19 ===  dex <&> dot in
   let num20 ===  dex <&> dot <&> dex in

   let num21 ===  dex <&> dot <&> dex <&>
                  ANY("Ee") in
   let num23 ===  dex <&> dot <&> dex <&>
                  ANY("Ee") <&> dex in

   let num25 ===  dex <&> dot <&> dex <&>
                  ANY("Ee") <&> ANY("+-") <&> dex in

   let num27 ===  dex <&> dot <&> ANY("Ee") in
   let num29 ===  dex <&> dot <&> ANY("Ee") <&>
                  dex in
   let num31 ===  dex <&> dot <&> ANY("Ee") <&>
                  ANY("+-") <&> dex in

     num11 <|> num13 <|> num15 <|> num19 <|>
     num20 <|> num21 <|> num23 <|> num25 <|>
     num27 <|> num29 <|> num31 <|> num33 <|>
     num34 <|> num36 <|> num38 ;


dcl Val__oct : str ;
say Val__oct <== LexShow(Val_oct) ;

write "\n\nOct: " <> num2str(length(Val__oct)) <> "\n" <> Val__oct ;


dcl Val__int : str ;
say Val__int <== LexShow(Val_int) ;

write "\n\nInt: " <> num2str(length(Val__int)) <> "\n" <> Val__int ;


dcl Val__hex : str ;
say Val__hex <== LexShow(Val_hex) ;

write "\n\nHex: " <> num2str(length(Val__hex)) <> "\n" <> Val__hex ;


dcl Val__flt : str ;
say Val__flt <== LexShow(Val_flt) ;

write "\n\nFlt: " <> num2str(length(Val__flt)) <> "\n" <> Val__flt ;

cshow off;
write ( [ Val__oct <> "\n\n" <>
          Val__int <> "\n\n" <>
          Val__hex <> "\n\n" <>
          Val__flt ] ) to "Values.lex" ;
cshow on;