token.c

   1 #include <ctype.h>
   2 #include <stdbool.h>
   3 #include <stdlib.h>
   4 #include <stdio.h>
   5 #include <string.h>
   6
   7 #include "token.h"
   8
   9 char *keywords[] =
  10 {
  11                  "boolean","char", "class", "constructor", "do", "else",
  12                  "false", "field", "function", "if", "int", "let", "method",
  13                  "null", "return", "static", "this", "true", "var", "void", "while"
  14 };
  15
  16 int has_more_tokens(char *pC)
  17 {
  18         if(*(pC+1) == '\0')
  19         {
  20                 return false;
  21         } else {
  22                 return true;
  23         }
  24 }
  25
  26 char *advance(char *pC, char pT[])
  27 {
  28         char ch;
  29         int cont; /* continue */
  30         int in_quote = 0; /* inside quotes? */
  31         do {
  32                 cont = 0;
  33                 /* skip past C++ style comments */
  34                 if(*pC == '/' && *(pC+1) == '/')
  35                 {
  36                         pC = strchr(pC, '\n');
  37                 }
  38
  39                 /* skip past C style comments */
  40                 if(*pC == '/' && *(pC+1) == '*')
  41                 {
  42                         pC++;
  43                         pC = strchr(pC, '/');
  44                         pC++;
  45                 }
  46
  47                 /* advance past spaces and newline chars */
  48                 ch = *pC;
  49                 while((strchr(SPACES, ch)) != NULL)
  50                 {
  51                         pC++;
  52                         ch = *pC;
  53                 }
  54
  55                 /* determine if more advancement is needed */
  56                 if(*pC == '/' && *(pC+1) == '/') { cont++; }
  57                 if(*pC == '/' && *(pC+1) == '*') { cont++; }
  58
  59         } while (cont);
  60
  61         /* test for symbol - copy to buffer */
  62         ch = *pC;
  63         if(strchr(SYMBOLS, ch) != NULL)
  64         {
  65                 pT[0] = ch;
  66                 pT[1] = '\0';
  67                 pC++;
  68                 return pC;
  69         }
  70
  71         /* should be at beginning of token - copy to buffer */
  72         cont = 0; in_quote = 0;
  73         if(*pC == '"')
  74         {
  75                 in_quote++; /* inside quote */
  76                 pC++;           /* skip quote itself */
  77         }
  78         while(TRUE)
  79         {
  80                 if(in_quote){
  81                         if(*pC == '"') {  pC++; break; } /* found corresponding quote, stop */
  82                 } else {
  83                         if(((strchr(SPACES, ch)) != NULL) || ((strchr(SYMBOLS, ch)) != NULL))
  84                         {
  85                                 break;
  86                         }
  87                 }
  88                 pT[cont] = *pC;
  89                 pC++;
  90                 ch = *pC;
  91                 cont++;
  92         }
  93         pT[cont] = '\0';
  94         return pC;
  95 }
  96
  97
  98 token token_type(char pT[])
  99 {
 100         token t = IDENTIFIER;
 101         int i = 0, j = 0;;
 102
 103         /* check token for symbols */
 104         if(strchr(SYMBOLS, pT[0]) != NULL) { t = SYMBOL; }
 105
 106         /* check token for integer constants */
 107         while(pT[i] != '\0')
 108         {
 109                 if(isdigit(pT[i]) == 0)
 110                 {
 111                         j++;
 112                         break;
 113                 }
 114                 i++;
 115         }
 116         if(j == 0) { t = INT_CONST; }
 117
 118         /* check token for keywords */
 119         i = 0; j = 0;
 120         do {
 121                 j = strcmp(keywords[i], pT);
 122                 i++;
 123         } while ((j != 0) && (i < KEYWORD_COUNT));
 124
 125         if(j == 0) { t = KEYWORD; }
 126         return t;
 127 }
 128
 129
 130  ttype keyword(char pT[])
 131 {
 132          int i = 0;
 133          do {
 134                  i++;
 135          } while (strcmp(pT, keywords[i]) < 0 && i < KEYWORD_COUNT);
 136         return i;
 137 }
 138
 139
 140 char symbol()
 141 {
 142         return 'z';
 143 }
 144
 145
 146 char *identifier(char *str)
 147 {
 148         str = NULL;
 149         return NULL;
 150 }
 151
 152
 153 int int_val(char pT[])
 154 {
 155         return atoi(pT);
 156 }
 157
 158
 159 char *string_val()
 160 {
 161         return NULL;
 162 }