roff.h

   1 /*
   2  * Most functions and variables in neatroff are prefixed with tokens
   3  * that indicate their purpose, such as:
   4  *
   5  * + tr_xyz: the implementation of troff request .xyz (mostly tr.c)
   6  * + in_xyz: input layer (in.c)
   7  * + cp_xyz: copy-mode interpretation layer (cp.c)
   8  * + ren_xyz: rendering characters into lines (ren.c)
   9  * + out_xyz: output layer for generating troff output (out.c)
  10  * + dev_xyz: output devices (dev.c)
  11  * + num_xyz: number registers (reg.c)
  12  * + str_xyz: string registers (reg.c)
  13  * + env_xyz: environments (reg.c)
  14  * + eval_xyz: integer expression evaluation (eval.c)
  15  * + font_xyz: fonts (font.c)
  16  * + sbuf_xyz: variable length string buffers (sbuf.c)
  17  * + dict_xyz: dictionaries (dict.c)
  18  * + wb_xyz: word buffers (wb.c)
  19  * + fmt_xyz: line formatting buffers (fmt.c)
  20  * + n_xyz: builtin number register xyz
  21  * + c_xyz: characters for requests like hc and mc
  22  *
  23  */
  24
  25 /* predefined array limits */
  26 #define PATHLEN         1024    /* path length */
  27 #define NFILES          16      /* number of input files */
  28 #define NFONTS          32      /* number of fonts */
  29 #define FNLEN           32      /* font name length */
  30 #define GNLEN           32      /* glyph name length */
  31 #define NMLEN           128     /* macro/register/environment name length */
  32 #define RNLEN           NMLEN   /* register/macro name */
  33 #define NREGS           8192    /* number of mapped names */
  34 #define ILNLEN          1000    /* line limit of input files */
  35 #define NARGS           32      /* number of macro arguments */
  36 #define NPREV           16      /* environment stack depth */
  37 #define NTRAPS          1024    /* number of traps per page */
  38 #define NIES            128     /* number of nested .ie commands */
  39 #define NTABS           16      /* number of tab stops */
  40 #define NCMAPS          512     /* number of character translations (.tr) */
  41 #define NSSTR           32      /* number of nested sstr_push() calls */
  42 #define NFIELDS         32      /* number of fields */
  43 #define NCHARS          32      /* number of characters for .eos, .hydash, .hystop */
  44 #define MAXFRAC         100000  /* maximum value of the fractional part */
  45 #define NCDEFS          128     /* number of character definitions (.char) */
  46 #define NHYPHS          16384   /* hyphenation dictionary/patterns (.hw) */
  47 #define NHYPHSWORD      16      /* number of hyphenations per word */
  48 #define NHCODES         512     /* number of .hcode characters */
  49 #define WORDLEN         256     /* word length (for hyph.c) */
  50 #define NFEATS          128     /* number of features per font */
  51 #define NSCRPS          64      /* number of scripts per font */
  52 #define NLANGS          64      /* number of languages per font */
  53
  54 /* converting scales */
  55 #define SC_IN           (dev_res)       /* inch in units */
  56 #define SC_PT           (SC_IN / 72)    /* point in units */
  57 #define SC_EM           (n_s * SC_IN / 72)
  58
  59 /* escape sequences */
  60 #define ESC_Q   "bCDhHjlLNoRSvwxXZ?"    /* \X'ccc' quoted escape sequences */
  61 #define ESC_P   "*fgkmns"               /* \Xc \X(cc \X[ccc] escape sequences */
  62
  63 #define MIN(a, b)       ((a) < (b) ? (a) : (b))
  64 #define MAX(a, b)       ((a) < (b) ? (b) : (a))
  65 #define LEN(a)          (sizeof(a) / sizeof((a)[0]))
  66
  67 /* special characters */
  68 extern int c_ec;        /* escape character (\) */
  69 extern int c_cc;        /* basic control character (.) */
  70 extern int c_c2;        /* no-break control character (') */
  71 extern char c_pc[];     /* page number character (%) */
  72 #define c_ni    4       /* non-interpreted copy-mode escape */
  73 #define c_hc    env_hc()/* hyphenation character */
  74 #define c_mc    env_mc()/* margin character (.mc) */
  75 #define c_tc    env_tc()
  76 #define c_lc    env_lc()
  77 #define c_bp    "\\:"   /* zero-width word break point */
  78 #define c_nb    "\\~"   /* stretchable no-break space */
  79
  80 /* number registers */
  81 #define num_get(id)     (*nreg(id))
  82 void num_set(int id, int val);
  83 void num_inc(int id, int pos);
  84 void num_del(int id);
  85 char *num_str(int id);
  86 char *num_getfmt(int id);
  87 void num_setfmt(int id, char *fmt);
  88 void num_setinc(int id, int val);
  89 int *nreg(int id);
  90 int eval(char *s, int unit);
  91 int eval_up(char **s, int unit);
  92 int eval_re(char *s, int orig, int unit);
  93
  94 /* string registers */
  95 void str_set(int id, char *s);
  96 void str_dset(int id, void *d);
  97 char *str_get(int id);
  98 void *str_dget(int id);
  99 void str_rm(int id);
 100 void str_rn(int src, int dst);
 101
 102 /* saving and restoring registers before and after printing diverted lines */
 103 void odiv_beg(void);
 104 void odiv_end(void);
 105
 106 /* enviroments */
 107 void env_init(void);
 108 void env_done(void);
 109 struct fmt *env_fmt(void);
 110 struct wb *env_wb(void);
 111 char *env_hc(void);
 112 char *env_mc(void);
 113 char *env_tc(void);
 114 char *env_lc(void);
 115 int tab_next(int pos);
 116 int tab_type(int pos);
 117
 118 /* mapping integers to sets */
 119 struct iset *iset_make(void);
 120 void iset_free(struct iset *iset);
 121 int *iset_get(struct iset *iset, int key);
 122 void iset_put(struct iset *iset, int key, int ent);
 123 int iset_len(struct iset *iset, int key);
 124
 125 /* mapping strings to longs */
 126 struct dict *dict_make(int notfound, int dupkeys, int hashlen);
 127 void dict_free(struct dict *d);
 128 void dict_put(struct dict *d, char *key, int val);
 129 int dict_get(struct dict *d, char *key);
 130 int dict_idx(struct dict *d, char *key);
 131 char *dict_key(struct dict *d, int idx);
 132 int dict_val(struct dict *d, int idx);
 133 int dict_prefix(struct dict *d, char *key, int *idx);
 134
 135 /* device related variables */
 136 extern int dev_res;
 137 extern int dev_uwid;
 138 extern int dev_hor;
 139 extern int dev_ver;
 140
 141 struct glyph {
 142         char id[GNLEN];         /* device-dependent glyph identifier */
 143         char name[GNLEN];       /* the first character mapped to this glyph */
 144         struct font *font;      /* glyph font */
 145         short wid;              /* character width */
 146         short llx, lly, urx, ury;       /* character bounding box */
 147         short type;             /* character type; ascender/descender */
 148 };
 149
 150 /* output device functions */
 151 int dev_open(char *dir, char *dev);
 152 void dev_close(void);
 153 int dev_mnt(int pos, char *id, char *name);
 154 int dev_pos(char *id);
 155 struct font *dev_font(int pos);
 156 int dev_fontpos(struct font *fn);
 157 struct glyph *dev_glyph(char *c, int fn);
 158
 159 /* font-related functions */
 160 struct font *font_open(char *path);
 161 void font_close(struct font *fn);
 162 struct glyph *font_glyph(struct font *fn, char *id);
 163 struct glyph *font_find(struct font *fn, char *name);
 164 int font_map(struct font *fn, char *name, char *id);
 165 int font_mapped(struct font *fn, char *name);
 166 int font_special(struct font *fn);
 167 int font_wid(struct font *fn, int sz, int w);
 168 int font_gwid(struct font *fn, struct font *cfn, int sz, int w);
 169 int font_swid(struct font *fn, int sz, int ss);
 170 void font_setcs(struct font *fn, int cs, int ps);
 171 int font_getcs(struct font *fn);
 172 void font_setbd(struct font *fn, int bd);
 173 int font_getbd(struct font *fn);
 174 void font_track(struct font *fn, int s1, int n1, int s2, int n2);
 175 void font_setzoom(struct font *fn, int zoom);
 176 int font_zoom(struct font *fn, int sz);
 177 int font_feat(struct font *fn, char *name, int val);
 178 void font_scrp(struct font *fn, char *name);
 179 void font_lang(struct font *fn, char *name);
 180 int font_layout(struct font *fn, struct glyph **src, int nsrc, int sz,
 181                 struct glyph **dst, int *dmap,
 182                 int *x, int *y, int *xadv, int *yadv, int lg, int kn);
 183
 184 /* different layers of neatroff */
 185 int in_next(void);              /* input layer */
 186 int cp_next(void);              /* copy-mode layer */
 187 int tr_next(void);              /* troff layer */
 188
 189 void in_push(char *s, char **args);
 190 void in_so(char *path);         /* .so request */
 191 void in_nx(char *path);         /* .nx request */
 192 void in_ex(void);               /* .ex request */
 193 void in_lf(char *path, int ln); /* .lf request */
 194 void in_queue(char *path);      /* queue the given input file */
 195 char *in_arg(int i);            /* look up argument */
 196 int in_nargs(void);             /* number of arguments */
 197 void in_shift(void);            /* shift the arguments */
 198 void in_back(int c);            /* push back input character */
 199 int in_top(void);               /* the first pushed-back character */
 200 char *in_filename(void);        /* current filename */
 201 int in_lnum(void);              /* current line number */
 202
 203 void cp_blk(int skip);          /* skip or read the next line or block */
 204 void cp_reqbeg(void);           /* beginning of a request line */
 205 void cp_copymode(int mode);     /* do not interpret \w and \E */
 206 #define cp_back         in_back /* cp.c is stateless */
 207 int tr_nextreq(void);           /* read the next troff request */
 208 void tr_req(int reg, char **args);      /* execute a built-in troff request */
 209
 210 /* variable length string buffer */
 211 struct sbuf {
 212         char *s;                /* allocated buffer */
 213         int sz;                 /* buffer size */
 214         int n;                  /* length of the string stored in s */
 215 };
 216
 217 void sbuf_init(struct sbuf *sbuf);
 218 void sbuf_done(struct sbuf *sbuf);
 219 char *sbuf_out(struct sbuf *sbuf);
 220 char *sbuf_buf(struct sbuf *sbuf);
 221 void sbuf_add(struct sbuf *sbuf, int c);
 222 void sbuf_append(struct sbuf *sbuf, char *s);
 223 void sbuf_printf(struct sbuf *sbuf, char *s, ...);
 224 void sbuf_cut(struct sbuf *sbuf, int n);
 225 int sbuf_len(struct sbuf *sbuf);
 226 int sbuf_empty(struct sbuf *sbuf);
 227
 228 /* word buffer */
 229 struct wb {
 230         struct sbuf sbuf;
 231         int f, s, m, cd;        /* the last output font and size */
 232         int r_f, r_s, r_m, r_cd;/* current font and size; use n_f and n_s if -1 */
 233         int part;               /* partial input (\c) */
 234         int cost;               /* the extra cost of line break after this word */
 235         int els_neg, els_pos;   /* extra line spacing */
 236         int h, v;               /* buffer vertical and horizontal positions */
 237         int ct, sb, st;         /* \w registers */
 238         int llx, lly, urx, ury; /* bounding box */
 239         int icleft;             /* pending left italic correction */
 240         /* queued subword */
 241         char sub_c[WORDLEN][GNLEN];     /* the collected subword */
 242         int sub_n;              /* collected subword length */
 243         int sub_collect;        /* enable subword collection */
 244 };
 245
 246 void wb_init(struct wb *wb);
 247 void wb_done(struct wb *wb);
 248 void wb_hmov(struct wb *wb, int n);
 249 void wb_vmov(struct wb *wb, int n);
 250 void wb_els(struct wb *wb, int els);
 251 void wb_etc(struct wb *wb, char *x);
 252 void wb_put(struct wb *wb, char *c);
 253 void wb_putraw(struct wb *wb, char *c);
 254 void wb_putexpand(struct wb *wb, char *c);
 255 int wb_part(struct wb *wb);
 256 void wb_setpart(struct wb *wb);
 257 int wb_cost(struct wb *wb);
 258 void wb_setcost(struct wb *wb, int cost);
 259 void wb_drawl(struct wb *wb, int c, int h, int v);
 260 void wb_drawc(struct wb *wb, int c, int r);
 261 void wb_drawe(struct wb *wb, int c, int h, int v);
 262 void wb_drawa(struct wb *wb, int c, int h1, int v1, int h2, int v2);
 263 void wb_drawxbeg(struct wb *wb, int c);
 264 void wb_drawxdot(struct wb *wb, int h, int v);
 265 void wb_drawxcmd(struct wb *wb, char *cmd);
 266 void wb_drawxend(struct wb *wb);
 267 void wb_italiccorrection(struct wb *wb);
 268 void wb_italiccorrectionleft(struct wb *wb);
 269 void wb_cat(struct wb *wb, struct wb *src);
 270 void wb_catstr(struct wb *wb, char *beg, char *end);
 271 int wb_wid(struct wb *wb);
 272 int wb_hpos(struct wb *wb);
 273 int wb_vpos(struct wb *wb);
 274 int wb_empty(struct wb *wb);
 275 int wb_eos(struct wb *wb);
 276 void wb_wconf(struct wb *wb, int *ct, int *st, int *sb,
 277                 int *llx, int *lly, int *urx, int *ury);
 278 void wb_reset(struct wb *wb);
 279 char *wb_buf(struct wb *wb);
 280 void wb_fnszget(struct wb *wb, int *fn, int *sz, int *m, int *cd);
 281 void wb_fnszset(struct wb *wb, int fn, int sz, int m, int cd);
 282 void wb_flushdir(struct wb *wb);
 283 void wb_reset(struct wb *wb);
 284 int wb_keshideh(char *word, struct wb *dst, int wid);
 285 int wb_hywid(struct wb *wb);
 286 int wb_swid(struct wb *wb);
 287 int c_eossent(char *s);
 288 int c_eostran(char *s);
 289 int c_hydash(char *s);
 290 int c_hystop(char *s);
 291 int c_hymark(char *s);
 292
 293 /* character translation (.tr) */
 294 void cmap_add(char *c1, char *c2);
 295 char *cmap_map(char *c);
 296 /* character definition (.char) */
 297 char *cdef_map(char *c, int fn);
 298 int cdef_expand(struct wb *wb, char *c, int fn);
 299
 300 /* hyphenation flags */
 301 #define HY_LAST         0x02    /* do not hyphenate last lines */
 302 #define HY_FINAL2       0x04    /* do not hyphenate the final two characters */
 303 #define HY_FIRST2       0x08    /* do not hyphenate the first two characters */
 304
 305 void hyphenate(char *hyphs, char *word, int flg);
 306 int hy_cput(char *d, char *s);
 307 void hyph_init(void);
 308 void hyph_done(void);
 309
 310 /* adjustment types */
 311 #define AD_C            0       /* center */
 312 #define AD_L            1       /* adjust left margin (flag) */
 313 #define AD_R            2       /* adjust right margin (flag) */
 314 #define AD_B            3       /* adjust both margin (mask) */
 315 #define AD_P            4       /* paragraph-at-once adjustment (flag) */
 316 #define AD_K            8       /* keshideh adjustment (flag) */
 317
 318 /* line formatting */
 319 struct fmt *fmt_alloc(void);
 320 void fmt_free(struct fmt *fmt);
 321 int fmt_wid(struct fmt *fmt);
 322 void fmt_space(struct fmt *fmt);
 323 void fmt_suppressnl(struct fmt *fmt);
 324 int fmt_word(struct fmt *fmt, struct wb *wb);
 325 int fmt_newline(struct fmt *fmt);
 326 int fmt_fillreq(struct fmt *f);
 327 int fmt_fill(struct fmt *fmt, int br);
 328 int fmt_morelines(struct fmt *fmt);
 329 int fmt_morewords(struct fmt *fmt);
 330 char *fmt_nextline(struct fmt *fmt, int *w,
 331                 int *li, int *lI, int *ll, int *els_neg, int *els_pos);
 332
 333 /* rendering */
 334 int render(void);                               /* the main loop */
 335 int ren_parse(struct wb *wb, char *c);
 336 int ren_char(struct wb *wb, int (*next)(void), void (*back)(int));
 337 int ren_wid(int (*next)(void), void (*back)(int));
 338 void ren_tl(int (*next)(void), void (*back)(int));
 339 void ren_hline(struct wb *wb, int l, char *c);  /* horizontal line */
 340 void ren_hlcmd(struct wb *wb, char *arg);       /* \l */
 341 void ren_vlcmd(struct wb *wb, char *arg);       /* \L */
 342 void ren_bcmd(struct wb *wb, char *arg);        /* \b */
 343 void ren_ocmd(struct wb *wb, char *arg);        /* \o */
 344 void ren_dcmd(struct wb *wb, char *arg);        /* \D */
 345 void ren_zcmd(struct wb *wb, char *arg);        /* \Z */
 346
 347 /* out.c */
 348 void out_line(char *s);                         /* output rendered line */
 349 void out(char *s, ...);                         /* output troff cmd */
 350
 351 /* troff commands */
 352 void tr_ab(char **args);
 353 void tr_bp(char **args);
 354 void tr_br(char **args);
 355 void tr_ce(char **args);
 356 void tr_ch(char **args);
 357 void tr_cl(char **args);
 358 void tr_di(char **args);
 359 void tr_divbeg(char **args);
 360 void tr_divend(char **args);
 361 void tr_divvs(char **args);
 362 void tr_dt(char **args);
 363 void tr_em(char **args);
 364 void tr_ev(char **args);
 365 void tr_fc(char **args);
 366 void tr_fi(char **args);
 367 void tr_fp(char **args);
 368 void tr_fspecial(char **args);
 369 void tr_ft(char **args);
 370 void tr_hcode(char **args);
 371 void tr_hpf(char **args);
 372 void tr_hpfa(char **args);
 373 void tr_hw(char **args);
 374 void tr_in(char **args);
 375 void tr_ll(char **args);
 376 void tr_mk(char **args);
 377 void tr_ne(char **args);
 378 void tr_nf(char **args);
 379 void tr_ns(char **args);
 380 void tr_os(char **args);
 381 void tr_pn(char **args);
 382 void tr_ps(char **args);
 383 void tr_rs(char **args);
 384 void tr_rt(char **args);
 385 void tr_sp(char **args);
 386 void tr_sv(char **args);
 387 void tr_ta(char **args);
 388 void tr_ti(char **args);
 389 void tr_wh(char **args);
 390 void tr_popren(char **args);
 391 void tr_transparent(char **args);
 392
 393 void tr_in2(char **args);
 394 void tr_ti2(char **args);
 395 void tr_l2r(char **args);
 396 void tr_r2l(char **args);
 397
 398 void tr_init(void);
 399 void tr_done(void);
 400
 401 char *tr_args(char **args, int brk, int (*next)(void), void (*back)(int));
 402
 403 /* helpers */
 404 void errmsg(char *msg, ...);
 405 void errdie(char *msg);
 406 void *xmalloc(long len);
 407 void *mextend(void *old, long oldsz, long newsz, int memsz);
 408 /* utf-8 parsing */
 409 int utf8len(int c);
 410 int utf8next(char *s, int (*next)(void));
 411 int utf8read(char **s, char *d);
 412 int utf8one(char *s);
 413 /* reading escapes and characters */
 414 int charnext(char *c, int (*next)(void), void (*back)(int));
 415 int charread(char **s, char *c);
 416 int charnext_delim(char *c, int (*next)(void), void (*back)(int), char *delim);
 417 int charread_delim(char **s, char *c, char *delim);
 418 void charnext_str(char *d, char *c);
 419 char *quotednext(int (*next)(void), void (*back)(int));
 420 char *unquotednext(int cmd, int (*next)(void), void (*back)(int));
 421 int escread(char **s, char **d);
 422 /* string streams; nested next()/back() interface for string buffers */
 423 void sstr_push(char *s);
 424 char *sstr_pop(void);
 425 int sstr_next(void);
 426 void sstr_back(int c);
 427
 428 /* internal commands */
 429 #define TR_DIVBEG       "\07<"  /* diversion begins */
 430 #define TR_DIVEND       "\07>"  /* diversion ends */
 431 #define TR_DIVVS        "\07V"  /* the amount of \n(.v inside diversions */
 432 #define TR_POPREN       "\07P"  /* exit render_rec() */
 433
 434 /* mapping register, macro and environment names to indices */
 435 #define DOTMAP(c2)      (c2)    /* optimized mapping for ".x" names */
 436
 437 int map(char *s);               /* map name s to an index */
 438 char *map_name(int id);         /* return the name mapped to id */
 439 void map_done(void);
 440
 441 /* text direction */
 442 extern int dir_do;
 443
 444 void dir_fix(struct sbuf *sbuf, char *s);
 445 void dir_done(void);
 446
 447 /* colors */
 448 #define CLR_R(c)                (((c) >> 16) & 0xff)
 449 #define CLR_G(c)                (((c) >> 8) & 0xff)
 450 #define CLR_B(c)                ((c) & 0xff)
 451 #define CLR_RGB(r, g, b)        (((r) << 16) | ((g) << 8) | (b))
 452
 453 char *clr_str(int c);
 454 int clr_get(char *s);
 455
 456 /* builtin number registers; n_X for .X register */
 457 #define n_a             (*nreg(DOTMAP('a')))
 458 #define n_cp            (*nreg(DOTMAP('C')))
 459 #define n_d             (*nreg(DOTMAP('d')))
 460 #define n_f             (*nreg(DOTMAP('f')))
 461 #define n_h             (*nreg(DOTMAP('h')))
 462 #define n_i             (*nreg(DOTMAP('i')))
 463 #define n_it            (*nreg(map(".it")))     /* .it trap macro */
 464 #define n_itn           (*nreg(map(".itn")))    /* .it lines left */
 465 #define n_I             (*nreg(DOTMAP('I')))    /* base indent */
 466 #define n_j             (*nreg(DOTMAP('j')))
 467 #define n_l             (*nreg(DOTMAP('l')))
 468 #define n_L             (*nreg(DOTMAP('L')))
 469 #define n_lsn           (*nreg(map("lsn")))     /* for .lsm */
 470 #define n_n             (*nreg(DOTMAP('n')))
 471 #define n_nI            (*nreg(map(".nI")))     /* i for .nm */
 472 #define n_nm            (*nreg(map(".nm")))     /* .nm enabled */
 473 #define n_nM            (*nreg(map(".nM")))     /* m for .nm */
 474 #define n_nn            (*nreg(map(".nn")))     /* remaining .nn */
 475 #define n_nS            (*nreg(map(".nS")))     /* s for .nm */
 476 #define n_m             (*nreg(DOTMAP('m')))
 477 #define n_mc            (*nreg(map(".mc")))     /* .mc enabled */
 478 #define n_mcn           (*nreg(map(".mcn")))    /* .mc distance */
 479 #define n_o             (*nreg(DOTMAP('o')))
 480 #define n_p             (*nreg(DOTMAP('p')))
 481 #define n_s             (*nreg(DOTMAP('s')))
 482 #define n_u             (*nreg(DOTMAP('u')))
 483 #define n_v             (*nreg(DOTMAP('v')))
 484 #define n_ct            (*nreg(map("ct")))
 485 #define n_td            (*nreg(map(".td")))     /* text direction */
 486 #define n_cd            (*nreg(map(".cd")))     /* current direction */
 487 #define n_dl            (*nreg(map("dl")))
 488 #define n_dn            (*nreg(map("dn")))
 489 #define n_ln            (*nreg(map("ln")))
 490 #define n_nl            (*nreg(map("nl")))
 491 #define n_sb            (*nreg(map("sb")))
 492 #define n_st            (*nreg(map("st")))
 493 #define n_pg            (*nreg(map("%")))       /* % */
 494 #define n_lb            (*nreg(map(".b0")))     /* input line beg */
 495 #define n_ce            (*nreg(map(".ce")))     /* .ce remaining */
 496 #define n_f0            (*nreg(map(".f0")))     /* last .f */
 497 #define n_lg            (*nreg(map(".lg")))     /* .lg mode */
 498 #define n_hy            (*nreg(map(".hy")))     /* .hy mode */
 499 #define n_hycost        (*nreg(map(".hycost"))) /* hyphenation cost */
 500 #define n_hycost2       (*nreg(map(".hycost2")))        /* hyphenation cost #2 */
 501 #define n_hycost3       (*nreg(map(".hycost3")))        /* hyphenation cost #3 */
 502 #define n_hlm           (*nreg(map(".hlm")))    /* .hlm */
 503 #define n_i0            (*nreg(map(".i0")))     /* last .i */
 504 #define n_ti            (*nreg(map(".ti")))     /* pending .ti */
 505 #define n_kn            (*nreg(map(".kn")))     /* .kn mode */
 506 #define n_tI            (*nreg(map(".tI")))     /* pending .ti2 */
 507 #define n_I0            (*nreg(map(".I0")))     /* last .I */
 508 #define n_l0            (*nreg(map(".l0")))     /* last .l */
 509 #define n_L0            (*nreg(map(".L0")))     /* last .L */
 510 #define n_m0            (*nreg(map(".m0")))     /* last .m */
 511 #define n_mk            (*nreg(map(".mk")))     /* .mk internal register */
 512 #define n_na            (*nreg(map(".na")))     /* .na mode */
 513 #define n_ns            (*nreg(map(".ns")))     /* .ns mode */
 514 #define n_o0            (*nreg(map(".o0")))     /* last .o */
 515 #define n_pmll          (*nreg(map(".pmll")))   /* minimum line length (.pmll) */
 516 #define n_pmllcost      (*nreg(map(".pmllcost")))       /* short line cost */
 517 #define n_ss            (*nreg(map(".ss")))     /* word space (.ss) */
 518 #define n_sss           (*nreg(map(".sss")))    /* sentence space (.ss) */
 519 #define n_ssh           (*nreg(map(".ssh")))    /* word space compression (.ssh) */
 520 #define n_s0            (*nreg(map(".s0")))     /* last .s */
 521 #define n_sv            (*nreg(map(".sv")))     /* .sv value */
 522 #define n_lt            (*nreg(map(".lt")))     /* .lt value */
 523 #define n_t0            (*nreg(map(".lt0")))    /* previous .lt value */
 524 #define n_v0            (*nreg(map(".v0")))     /* last .v */
 525 #define n_llx           (*nreg(map("bbllx")))   /* \w bounding box */
 526 #define n_lly           (*nreg(map("bblly")))   /* \w bounding box */
 527 #define n_urx           (*nreg(map("bburx")))   /* \w bounding box */
 528 #define n_ury           (*nreg(map("bbury")))   /* \w bounding box */
 529
 530 /* functions for implementing read-only registers */
 531 int f_nexttrap(void);   /* .t */
 532 int f_divreg(void);     /* .z */
 533 int f_hpos(void);       /* .k */