parser/scanner.lex

   1         #include <stdio.h>
   2         #include <stdlib.h>
   3         #include <string.h>
   4         #include "parser.h"
   5
   6 KEYWORD func|end|struct|var|if|then|else|while|do|return|or|not
   7 SPECIAL_CHAR \;|\.|\(|\)|\,|\:=|\-|\+|\*|>=|=
   8 IDENTIFIER [[:alpha:]_][[:alnum:]_]*
   9 NUMBER_HEX [0-9][0-9A-Fa-f]*H
  10 NUMBER_DEC [0-9]+
  11 WHITESPACE [\t\n\r ]
  12 COMMENT_START \(\*
  13 COMMENT_END \*\)
  14
  15 %x COMMENT
  16 %option yylineno
  17 %%
  18
  19 {COMMENT_START} BEGIN(COMMENT);
  20
  21 <COMMENT>{COMMENT_END} BEGIN(INITIAL);
  22
  23 <COMMENT>{COMMENT_START} fprintf(stderr, "Possibly nested comment on line %i\n", yylineno);
  24
  25 <COMMENT><<EOF>> {
  26         fprintf(stderr, "Unterminated comment.\n");
  27         exit(1);
  28 }
  29
  30 <COMMENT>{WHITESPACE} /* ignore */
  31
  32 <COMMENT>. /* ignore everything inside comment */
  33
  34 func return(FUNC);
  35 end return(END);
  36 struct return(STRUCT);
  37 var return(VAR);
  38 if return(IF);
  39 then return(THEN);
  40 else return(ELSE);
  41 while return(WHILE);
  42 do return(DO);
  43 return return(RETURN);
  44 or return(OR);
  45 not return(NOT);
  46
  47 {IDENTIFIER} return(ID);
  48
  49 {NUMBER_DEC} return(NUM);
  50 {NUMBER_HEX} return(NUM);
  51
  52 \:= return(ASSIGN);
  53 >= return(GREATER);
  54 {SPECIAL_CHAR} return(yytext[0]);
  55
  56 {WHITESPACE} /* ignore */
  57
  58 . {
  59                 fprintf(stderr, "Lexical error on line %i\n", yylineno);
  60                 exit(1);
  61 }
  62
  63 %%
  64