/* Copyright (c) 2018 Charles E. Youse (charles@gnuless.org). 
   All rights reserved.

 Redistribution and use in source and binary forms, with or without
 modification, are permitted provided that the following conditions are met:

 * Redistributions of source code must retain the above copyright notice, this
   list of conditions and the following disclaimer.

 * Redistributions in binary form must reproduce the above copyright notice,
   this list of conditions and the following disclaimer in the documentation
   and/or other materials provided with the distribution.

 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
 FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
 CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */

/* a token is comprised of a class and possibly some additional data
   in 'u' (see KK_* comments for details). */

struct token
{
    int kk;    

    union
    {
        long            i;
        double          f;     
        struct string * text;
    } u;
};

/* token classes are for the most part arbitrary values,
   except that binary operators that are parsed by binary()
   have an embedded precedence level. the pseudo tokens are
   used internally by the lexer and never seen by the parser. */

#define KK_PREC(x)              (0x00000100 << (x))

#define KK_PREC_MUL             0
#define KK_PREC_ADD             1
#define KK_PREC_SHIFT           2
#define KK_PREC_REL             3
#define KK_PREC_EQ              4
#define KK_PREC_AND             5
#define KK_PREC_XOR             6
#define KK_PREC_OR              7
#define KK_PREC_LAND            8
#define KK_PREC_LOR             9

#define KK_NONE                 0

#define KK_IDENT                1       /* identifier: u.text */
#define KK_STRLIT               2       /* string literal: u.text */
#define KK_FCON                 3       /* float constant: u.f */
#define KK_LFCON                4       /* long float constant: u.f */
#define KK_ICON                 5       /* int constant: u.i */
#define KK_LCON                 6       /* long constant: u.i */

#define KK_NL                   10      /* pseudo tokens */
#define KK_HASH                 11

#define KK_LPAREN   /* ( */     20      /* operators/punctuators */
#define KK_RPAREN   /* ) */     21     
#define KK_LBRACK   /* [ */     22      
#define KK_RBRACK   /* ] */     23      
#define KK_LBRACE   /* { */     24     
#define KK_RBRACE   /* } */     25      
#define KK_DOT      /* . */     26     
#define KK_XOR      /* ^ */     (27 | KK_PREC(KK_PREC_XOR))
#define KK_COMMA    /* , */     28  
#define KK_COLON    /* : */     29 
#define KK_SEMI     /* ; */     30      
#define KK_QUEST    /* ? */     31      
#define KK_TILDE    /* ~ */     32      
#define KK_ARROW    /* -> */    33   
#define KK_INC      /* ++ */    34      
#define KK_DEC      /* -- */    35     
#define KK_BANG     /* ! */     36     
#define KK_DIV      /* / */     (37 | KK_PREC(KK_PREC_MUL))
#define KK_STAR     /* * */     (38 | KK_PREC(KK_PREC_MUL))
#define KK_PLUS     /* + */     (39 | KK_PREC(KK_PREC_ADD))
#define KK_MINUS    /* - */     (40 | KK_PREC(KK_PREC_ADD))
#define KK_GT       /* > */     (41 | KK_PREC(KK_PREC_REL))
#define KK_SHR      /* >> */    (42 | KK_PREC(KK_PREC_SHIFT))
#define KK_GTEQ     /* >= */    (43 | KK_PREC(KK_PREC_REL))
#define KK_SHREQ    /* >>= */   44   
#define KK_LT       /* < */     (45 | KK_PREC(KK_PREC_REL))
#define KK_SHL      /* << */    (46 | KK_PREC(KK_PREC_SHIFT))
#define KK_LTEQ     /* <= */    (47 | KK_PREC(KK_PREC_REL))
#define KK_SHLEQ    /* <<= */   48 
#define KK_AND      /* & */     (49 | KK_PREC(KK_PREC_AND))
#define KK_ANDAND   /* && */    (50 | KK_PREC(KK_PREC_LAND))
#define KK_ANDEQ    /* &= */    51  
#define KK_BAR      /* | */     (52 | KK_PREC(KK_PREC_OR))
#define KK_BARBAR   /* || */    (53 | KK_PREC(KK_PREC_LOR)) 
#define KK_BAREQ    /* |= */    54
#define KK_MINUSEQ  /* -= */    55
#define KK_PLUSEQ   /* += */    56
#define KK_STAREQ   /* *= */    57
#define KK_DIVEQ    /* /= */    58
#define KK_EQEQ     /* == */    (59 | KK_PREC(KK_PREC_EQ))
#define KK_BANGEQ   /* != */    (60 | KK_PREC(KK_PREC_EQ))
#define KK_MOD      /* % */     (61 | KK_PREC(KK_PREC_MUL))
#define KK_MODEQ    /* %= */    62
#define KK_XOREQ    /* ^= */    63    
#define KK_EQ       /* = */     64  

    /* the keywords should be sequentially numbered
       in alphabetical order to match keyword[] in lex.c */

#define KK_AUTO                 70      /* keywords */
#define KK_BREAK                71      
#define KK_CASE                 72
#define KK_CHAR                 73
#define KK_CONTINUE             74
#define KK_DEFAULT              75
#define KK_DO                   76
#define KK_ELSE                 77
#define KK_EXTERN               78
#define KK_FLOAT                79
#define KK_FOR                  80
#define KK_GOTO                 81
#define KK_IF                   82
#define KK_INT                  83
#define KK_LONG                 84
#define KK_REGISTER             85
#define KK_RETURN               86
#define KK_SHORT                87
#define KK_SIZEOF               88
#define KK_STATIC               89
#define KK_STRUCT               90
#define KK_SWITCH               91
#define KK_TYPEDEF              92
#define KK_UNION                93
#define KK_UNSIGNED             94
#define KK_WHILE                95