buffer.h

#ifndef BUFFER_H
#define BUFFER_H

#include <stdbool.h>
#include <stdint.h>
#include <wchar.h>

#define NONE ((size_t)-1)
typedef size_t lineno;
typedef size_t colno;
struct POS{
    lineno l;
    colno c;
};

struct LINE{
    size_t a, n;
    wchar_t *s;
};

struct TAG{
   POS p1;
   POS p2;
   int v;
};

typedef enum{ /* note that these must be in descending order by priority */
   VIRTCURS,
   HIGHLIGHT,
   BLOCK,
   TAG_MAX
} tag;

typedef uint64_t txn;
struct BUFFER{
    size_t a, n;
    LINE *l;

    bool canundo, dirty;
    int nbegin;
    txn t;
    JOURNAL *j;

    TAG tags[TAG_MAX];
};

BUFFER *openbuffer(void);
void closebuffer(BUFFER *b);

bool insertline(BUFFER *b, lineno l);
bool inserttext(BUFFER *b, POS p, const wchar_t *s, size_t n);
bool deleteline(BUFFER *b, lineno l);
bool deletetext(BUFFER *b, POS p, size_t n);

wint_t charat(const BUFFER *b, POS p);

bool prev(const BUFFER *b, POS *p);
bool next(const BUFFER *b, POS *p);
bool attop(const BUFFER *b, POS p);
bool atbot(const BUFFER *b, POS p);
bool ateol(const BUFFER *b, POS p);

POS pos(lineno l, colno c);

bool settag(BUFFER *b, tag t, POS p1, POS p2, int v);
void cleartag(BUFFER *b, tag t);

void enableundo(BUFFER *b);
bool mark(BUFFER *b);
void begin(BUFFER *b);
bool commit(BUFFER *b);
bool undo(BUFFER *b, POS *p);
void clearundo(BUFFER *b);

#endif