fml/fmltoken.c

   1 /*
   2  * FML interpreter. Europagate, 1995
   3  *
   4  * $Log: fmltoken.c,v $
   5  * Revision 1.1  1995/02/06 13:48:09  adam
   6  * Initial revision
   7  *
   8  */
   9 #include <string.h>
  10 #include <assert.h>
  11 #include <stdio.h>
  12
  13 #include "fmlp.h"
  14
  15 static int look_char;
  16 static int look_type;
  17 static char lex_buf[FML_MAX_TOKEN];
  18
  19 static void lexer (Fml fml);
  20
  21 struct fml_node *fml_group (Fml fml);
  22
  23 struct fml_node *fml_tokenize (Fml fml)
  24 {
  25     struct fml_node *p;
  26
  27     look_char = (*fml->read_func)();
  28     p = fml_group (fml);
  29     if (fml->debug)
  30     {
  31         fml_pr_list (p);
  32         printf ("\n");
  33     }
  34     return p;
  35 }
  36
  37 void fml_pr_list (struct fml_node *p)
  38 {
  39     printf ("{");
  40
  41     while (p)
  42     {
  43         if (p->is_atom)
  44         {
  45             char buf[100];
  46             fml_atom_str (p->p[0], buf);
  47             printf (" %s", buf);
  48         }
  49         else
  50         {
  51             printf (" ");
  52             fml_pr_list (p->p[0]);
  53         }
  54         p = p->p[1];
  55     }
  56     printf (" }");
  57 }
  58
  59 struct fml_node *fml_group (Fml fml)
  60 {
  61     struct fml_node *ptr0 = NULL, *ptr1, *ptr2;
  62
  63     lexer (fml);
  64     if (look_type == 0)
  65         return NULL;
  66     while (1)
  67     {
  68         if (look_type == 'a')
  69         {
  70             ptr2 = fml_node_alloc (fml);
  71             if (!ptr0)
  72                 ptr0 = ptr2;
  73             else
  74                 ptr1->p[1] = ptr2;
  75             ptr2->p[0] = fml_atom_alloc (fml, lex_buf);
  76             ptr2->is_atom = 1;
  77         }
  78         else if (look_type == '{')
  79         {
  80             struct fml_node *sptr = fml_group (fml);
  81             if (sptr)
  82                 if (sptr->p[1])
  83                 {
  84                     ptr2 = fml_node_alloc (fml);
  85                     if (!ptr0)
  86                         ptr0 = ptr2;
  87                     else
  88                         ptr1->p[1] = ptr2;
  89                     ptr2->p[0] = sptr;
  90                     ptr2->is_atom = 0;
  91                 }
  92                 else
  93                 {
  94                     ptr2 = sptr;
  95                     if (!ptr0)
  96                         ptr0 = ptr2;
  97                     else
  98                         ptr1->p[1] = ptr2;
  99                 }
 100             else
 101             {
 102                 ptr2 = fml_node_alloc (fml);
 103                 if (!ptr0)
 104                     ptr0 = ptr2;
 105                 else
 106                     ptr1->p[1] = ptr2;
 107                 ptr2->is_atom = 0;
 108             }
 109         }
 110         else
 111             break;
 112         lexer (fml);
 113         ptr1 = ptr2;
 114     }
 115     return ptr0;
 116 }
 117
 118 static void lexer (Fml fml)
 119 {
 120     int off;
 121     while (1)
 122     {
 123         if (look_char == fml->eof_mark)
 124         {
 125             look_type = 0;
 126             return;
 127         }
 128         else if (look_char == fml->comment_char)
 129         {
 130             do
 131                 look_char = (*fml->read_func)();
 132             while (look_char != '\n' && look_char != fml->eof_mark);
 133         }
 134         else
 135         {
 136             if (!strchr (fml->white_chars, look_char))
 137                 break;
 138             look_char = (*fml->read_func)();
 139         }
 140     }
 141     if (look_char == '{')
 142     {
 143         look_type = '{';
 144         look_char = (*fml->read_func)();
 145     }
 146     else if (look_char == '}')
 147     {
 148         look_type = '}';
 149         look_char = (*fml->read_func)();
 150     }
 151     else
 152     {
 153         off = 0;
 154         do
 155         {
 156             lex_buf[off++] = look_char;
 157             look_char = (*fml->read_func)();
 158         } while (look_char != fml->eof_mark
 159                  && !strchr (fml->white_chars, look_char)
 160                  && look_char != '{' && look_char != '}');
 161         lex_buf[off] = '\0';
 162         look_type = 'a';
 163     }
 164 #if 0
 165     if (fml->debug)
 166     {
 167         if (look_type == 'a')
 168             printf ("[%s]", lex_buf);
 169         else
 170             printf ("[%c]", look_type);
 171     }
 172 #endif
 173 }