token.c

   1 #include <ctype.h>
   2 #include <stdlib.h>
   3 #include <stdio.h>
   4 #include <string.h>
   5
   6 #include "token.h"
   7
   8 char *keywords[] =
   9 {
  10                  "boolean","char", "class", "constructor", "do", "else",
  11                  "false", "field", "function", "if", "int", "let", "method",
  12                  "null", "return", "static", "this", "true", "var", "void", "while"
  13 };
  14
  15 int has_more_tokens(char *pC)
  16 {
  17         if(*(pC+1) == '\0')
  18         {
  19                 return FALSE;
  20         } else {
  21                 return TRUE;
  22         }
  23 }
  24
  25 char *advance(char *pC, char pT[])
  26 {
  27         char ch;
  28         int cont; /* continue */
  29         int in_quote = 0; /* inside quotes? */
  30         do {
  31                 cont = 0;
  32                 /* skip past C++ style comments */
  33                 if(*pC == '/' && *(pC+1) == '/')
  34                 {
  35                         pC = strchr(pC, '\n');
  36                 }
  37
  38                 /* skip past C style comments */
  39                 if(*pC == '/' && *(pC+1) == '*')
  40                 {
  41                         pC++;
  42                         pC = strchr(pC, '/');
  43                         pC++;
  44                 }
  45
  46                 /* advance past spaces and newline chars */
  47                 ch = *pC;
  48                 while((strchr(SPACES, ch)) != NULL)
  49                 {
  50                         pC++;
  51                         ch = *pC;
  52                 }
  53
  54                 /* determine if more advancement is needed */
  55                 if(*pC == '/' && *(pC+1) == '/') { cont++; }
  56                 if(*pC == '/' && *(pC+1) == '*') { cont++; }
  57
  58         } while (cont);
  59
  60         /* test for symbol - copy to buffer */
  61         ch = *pC;
  62         if(strchr(SYMBOLS, ch) != NULL)
  63         {
  64                 pT[0] = ch;
  65                 pT[1] = '\0';
  66                 pC++;
  67                 return pC;
  68         }
  69
  70         /* should be at beginning of token - copy to buffer */
  71         cont = 0; in_quote = 0;
  72         if(*pC == '"')
  73         {
  74                 in_quote++; /* inside quote */
  75                 pC++;           /* skip quote itself */
  76         }
  77         while(TRUE)
  78         {
  79                 if(in_quote){
  80                         if(*pC == '"') {  pC++; break; } /* found corresponding quote, stop */
  81                 } else {
  82                         if(((strchr(SPACES, ch)) != NULL) || ((strchr(SYMBOLS, ch)) != NULL))
  83                         {
  84                                 break;
  85                         }
  86                 }
  87                 pT[cont] = *pC;
  88                 pC++;
  89                 ch = *pC;
  90                 cont++;
  91         }
  92         pT[cont] = '\0';
  93         return pC;
  94 }
  95
  96
  97 token token_type(char pT[])
  98 {
  99         token t = IDENTIFIER;
 100         int i = 0, j = 0;;
 101
 102         /* check token for symbols */
 103         if(strchr(SYMBOLS, pT[0]) != NULL) { t = SYMBOL; }
 104
 105         /* check token for integer constants */
 106         while(pT[i] != '\0')
 107         {
 108                 if(isdigit(pT[i]) == 0)
 109                 {
 110                         j++;
 111                         break;
 112                 }
 113                 i++;
 114         }
 115         if(j == 0) { t = INT_CONST; }
 116
 117         /* check token for keywords */
 118         i = 0; j = 0;
 119         do {
 120                 j = strcmp(keywords[i], pT);
 121                 i++;
 122         } while ((j != 0) && (i < KEYWORD_COUNT));
 123
 124         if(j == 0) { t = KEYWORD; }
 125         return t;
 126 }
 127
 128
 129  ttype keyword(char pT[])
 130 {
 131          int i = 0;
 132          do {
 133                  i++;
 134          } while (strcmp(pT, keywords[i]) < 0 && i < KEYWORD_COUNT);
 135         return i;
 136 }
 137
 138
 139 char symbol()
 140 {
 141         return 'z';
 142 }
 143
 144
 145 char *identifier(char *str)
 146 {
 147         str = NULL;
 148         return NULL;
 149 }
 150
 151
 152 int int_val(char pT[])
 153 {
 154         return atoi(pT);
 155 }
 156
 157
 158 char *string_val()
 159 {
 160         return NULL;
 161 }