storybook/cyoa.leg

%{
  
#include <stdio.h>
#include <stdlib.h>
#include <assert.h>

typedef struct page_t page_t;
typedef struct footer_t footer_t;

typedef struct page_node_t page_node_t;
typedef struct choicelist choicelist;

struct page_node_t {
  page_t *page;
  page_node_t *next;
};

#define FOOTER_END	1
#define FOOTER_GOTO	2
#define FOOTER_CHOICES	3
struct footer_t {
  int type;
  union {
    choicelist *choices;
    char *link;
  };
};

struct page_t {
  char *id;
  char *body;
  footer_t footer;
};

typedef struct statcheck_t statcheck_t;
typedef struct statchange_t statchange_t;
typedef struct choice_t choice_t;

#define STATCHECK_GT 1
#define STATCHECK_LT 2

struct statcheck_t {
  char *stat;
  int value;
  int rel;
};

struct statchange_t {
  char *stat;
  int addend;
};


#define CHOICE_STATCHECK  0x1
#define CHOICE_STATCHANGE 0x2

struct choice_t {
  int flags;
  int option;
  char *flavor;
  statcheck_t statcheck;
  char *redirect;
  statchange_t statchange;
};

struct choicelist {
  choice_t *choice;
  choicelist *next;
};

page_node_t *pages;

choice_t *make_choice();

void add_page(page_t*);
void add_choice(page_t*, choice_t*);

page_t *emit_ending();
page_t *emit_goto(char*);
page_t *emit_choices();

void append_body(page_t *page, char *str);

union value {
  page_t *page;
  char *string;
  choice_t *choice;
};

#define YYSTYPE union value

%}


Story =        BlankLine* (p:Page { add_page(p.page); })+ EndOfFile;

Page =         h:Header b:Body { $$.page = b.page; $$.page->id = h.string}
     	        BlankLine*;

Header =       < Identifier > { $$.string = strndup(yytext, yyleng); }
               Newline BlankLine*;
               
Identifier =   [A-Z][A-Z0-9_]+;

Body =         Footer | t:TextLine b:Body { $$ = b; append_body(b.page, t.string);};

TextLine =     < (!Newline .)* Newline > { $$.string = strndup(yytext, yyleng); };

Footer =       Ending { $$.page = emit_ending(); }
	       | g:Goto { $$.page = emit_goto(g.string); }
	       | Choice+ { $$.page = emit_ending(); }
	       ;

Goto =         'GOTO' Spacing < i:Identifier > Newline
     	       { $$.string = strndup(yytext, yyleng); }
	       ;

Ending =       'THE END' Newline;

Choice =       { $$.choice = make_choice(); } [0-9]+ ')' Spacing < (!Redirect .)+ >  Redirect;

Redirect =     StatCheck? Spacing '[' Identifier ']' Spacing StatChange? Newline;

StatCheck =    '<' StatName Spacing [0-9]+ ('+' | '-')? '>';

StatChange =   '(' ('+' | '-') [0-9]+ Spacing StatName ')';

StatName =     [A-Za-z]+;

EndOfFile =    !.;

BlankLine =    Spacing Newline;

Spacing =      (' ' | '\t')*;

Newline =      '\r\n' | '\r' | '\n';

%%

void add_page(page_t *page) {
  page_node_t *mynode = (page_node_t*) malloc(sizeof(page_node_t));
  mynode->page = page;
  mynode->next = NULL;

  page_node_t *curr = pages;
  page_node_t *prev = NULL;
  
  if (curr) {
    for(; curr; prev = curr, curr = curr->next);
    prev->next = mynode;
  } else {
    pages = mynode;
  }
}

void add_choice(page_t *page, choice_t* choice) {
  assert(page != choice);
  choicelist *mychoices = (choicelist *) malloc(sizeof(choicelist));
  mychoices->choice = choice;
  mychoices->next = NULL;

  choicelist *curr = page->footer.choices;
  choicelist *prev = NULL;

  if (curr) {
    for(; curr; prev = curr, curr = curr->next);
    prev->next = mychoices;
  } else {
    page->footer.choices = mychoices;
  }
}

static inline page_t *make_page() {
  page_t *mypage = (page_t*) malloc(sizeof(page_t));
  mypage->id = NULL;
  mypage->body = NULL;
  return mypage;
}

inline choice_t *make_choice() {
  choice_t *mychoice = (choice_t*) malloc(sizeof(choice_t));
  mychoice->flags = 0x0;
  printf("choice 0x%x\n", mychoice);
  return mychoice;
}

page_t *emit_goto(char *id) {
  page_t *mypage = make_page();
  mypage->footer.type = FOOTER_GOTO;
  mypage->footer.link = id;
  return mypage;
}

page_t *emit_ending() {
  page_t *mypage = make_page();
  mypage->footer.type = FOOTER_END;
  return mypage;
}

page_t *emit_choices() {
  page_t *mypage = make_page();
  mypage->footer.type = FOOTER_CHOICES;
  mypage->footer.choices = NULL;
  printf("page 0x%x\n", mypage);
  return mypage;
}

void append_body(page_t *page, char *str) {
  if (page->body) {
    int size = strlen(page->body) + strlen(str) + 1;
    char *newstring = (char*) calloc(size, sizeof(char));
    strcpy(newstring, str);
    strcat(newstring, page->body);
    free(page->body);
    page->body = newstring;
  } else {
    page->body = str;
  }
}

void print_page(page_t *page) {
  printf("HEADER: %s\nBODY: %s\n", page->id, page->body);
  switch (page->footer.type) {
  case FOOTER_END:
    printf("THE END\n");
    break;
  case FOOTER_GOTO:
    printf("GOTO %s\n", page->footer.link);
    break;
  case FOOTER_CHOICES:
    printf("CHOICES:\n");
    break;
  }
}

int main() {
  if (!yyparse()) {
    printf("Parsing Error!\n");
    return 1;
  } else {
    for (page_node_t *curr = pages; curr; curr = curr->next) {
      print_page(curr->page);
    }
  }
  return 0;
}

/* Local Variables: */
/* mode: text */
/* End: */