jim-mk.cpp

   1 #include <string.h>
   2 #include <ctype.h>
   3 #include <new>
   4 #include <mk4.h>
   5
   6 #include "jim.h"
   7 #include "jimautoconf.h"
   8 #include "jim-subcmd.h"
   9
  10 extern "C" { /* The whole file is essentially C */
  11
  12 #define MK_PROPERTY_BINARY  'B'
  13 #define MK_PROPERTY_INT     'I'
  14 #define MK_PROPERTY_LONG    'L'
  15 #define MK_PROPERTY_FLOAT   'F'
  16 #define MK_PROPERTY_DOUBLE  'D'
  17 #define MK_PROPERTY_STRING  'S'
  18 #define MK_PROPERTY_VIEW    'V'
  19
  20 #define MK_MODE_ORIGINAL    -1
  21 #define MK_MODE_READONLY    0
  22 #define MK_MODE_READWRITE   1
  23 #define MK_MODE_EXTEND      2
  24
  25 #define MK_CMD_LEN 32
  26 #define JIM_CURSOR_SPACE (35+JIM_REFERENCE_TAGLEN + 1 + 20)
  27 #define JIM_POSITION_SPACE 32
  28 #define MK_VERSION_SPACE 16
  29 #define JIM_MK_DESCR_LEN 64 /* Default, will be reallocated if needed */
  30
  31 #define isnamech(c) ( (c) && !strchr(":,[^]!", (c)) )
  32
  33 #ifndef max
  34 #define max(x, y) ((x) >= (y) ? (x) : (y))
  35 #endif
  36
  37 /* utilities */
  38 static int JimCheckMkName(Jim_Interp *interp, Jim_Obj *name, const char *type);
  39 static const char *JimMkTypeName(char type);
  40 static Jim_Obj *JimFromMkDescription(Jim_Interp *interp, const char *descr, const char **endPtr);
  41 static int JimToMkDescription(Jim_Interp *interp, Jim_Obj *obj, char **descrPtr);
  42 static Jim_Obj *JimGetMkValue(Jim_Interp *interp, c4_Cursor cur, const c4_Property &prop);
  43 static int JimSetMkValue(Jim_Interp *interp, c4_Cursor cur, const c4_Property &prop, Jim_Obj *obj);
  44
  45 static int JimPipelineBoundary(int argc, Jim_Obj *const *argv);
  46
  47 /* property object */
  48 static Jim_Obj *JimNewPropertyObj (Jim_Interp *interp, c4_Property prop);
  49 static int JimGetProperty (Jim_Interp *interp, Jim_Obj *obj,
  50     c4_View view, const char *what, const c4_Property **propPtr);
  51 static int JimGetPropertyTyped (Jim_Interp *interp, Jim_Obj *obj,
  52     char type, const c4_Property **propPtr);
  53 static int JimGetNewProperty (Jim_Interp *interp, Jim_Obj *obj,
  54     c4_View view, char type, const c4_Property **propPtr);
  55 static int JimGetProperties (Jim_Interp *interp, int objc, Jim_Obj *const *objv,
  56     c4_View view, c4_View *propsPtr);
  57 static Jim_Obj *JimViewPropertiesList (Jim_Interp *interp, c4_View view);
  58
  59 /* cursor object */
  60 static int JimGetPosition (Jim_Interp *interp, Jim_Obj *obj, c4_View view, int *indexPtr);
  61 static int JimGetCursor (Jim_Interp *interp, Jim_Obj *obj, c4_Cursor *curPtr);
  62 static int JimGetCursorView (Jim_Interp *interp, Jim_Obj *obj,
  63     Jim_Obj **viewObjPtr);
  64 static int JimCursorPos (Jim_Interp *interp, Jim_Obj *obj, Jim_Obj **posObjPtr);
  65 static int JimIncrCursor (Jim_Interp *interp, Jim_Obj *obj, int offset);
  66 static int JimSeekCursor (Jim_Interp *interp, Jim_Obj *obj, Jim_Obj *posObj);
  67
  68 /* Also accepts JIM_ERRMSG */
  69 #define JIM_CURSOR_GET      (1 << JIM_PRIV_FLAG_SHIFT)
  70 #define JIM_CURSOR_SET      (2 << JIM_PRIV_FLAG_SHIFT)
  71 #define JIM_CURSOR_INSERT   (4 << JIM_PRIV_FLAG_SHIFT)
  72
  73 static int JimCheckCursor (Jim_Interp *interp, Jim_Obj *curObj, int flags);
  74
  75 /* view handle */
  76 static Jim_Obj *JimNewViewObj (Jim_Interp *interp, c4_View view);
  77 static int JimGetView (Jim_Interp *interp, Jim_Obj *obj, c4_View *viewPtr);
  78 static void JimPinView (Jim_Interp *interp, Jim_Obj *obj);
  79
  80 /* -------------------------------------------------------------------------
  81  * Utilities
  82  * ------------------------------------------------------------------------- */
  83
  84 static int JimCheckMkName(Jim_Interp *interp, Jim_Obj *name, const char *type)
  85 {
  86     const char *s;
  87     int i, len;
  88
  89     s = Jim_GetString(name, &len);
  90
  91     if (len > 0 && s[0] == '-')
  92         goto err;
  93     for (i = 0; i < len; i++) {
  94         if (!isnamech(s[i]))
  95             goto err;
  96     }
  97
  98     return JIM_OK;
  99
 100   err:
 101     Jim_SetResultFormatted(interp, "expected %s name but got \"%#s\"", type ? type : "property", name);
 102     return JIM_ERR;
 103 }
 104
 105 static const char *const jim_mktype_options[] = {
 106     "-integer",
 107     "-long",
 108     "-float",
 109     "-double",
 110     "-string",
 111     "-subview",
 112     /* FIXME "-binary", */
 113     0
 114 };
 115
 116 static const char *const jim_mktype_names[] = {
 117     "integer",
 118     "long",
 119     "float",
 120     "double",
 121     "string",
 122     "subview",
 123     /* FIXME "binary", */
 124     0
 125 };
 126
 127 static const char jim_mktype_types[] = {
 128     MK_PROPERTY_INT,
 129     MK_PROPERTY_LONG,
 130     MK_PROPERTY_FLOAT,
 131     MK_PROPERTY_DOUBLE,
 132     MK_PROPERTY_STRING,
 133     MK_PROPERTY_VIEW,
 134     /* MK_PROPERTY_BINARY, */
 135 };
 136
 137 #define JIM_MKTYPES ((int)(sizeof(jim_mktype_types) / sizeof(jim_mktype_types[0])))
 138
 139 static const char *JimMkTypeName(char type)
 140 {
 141     int i;
 142
 143     for (i = 0; i < JIM_MKTYPES; i++) {
 144         if (type == jim_mktype_types[i])
 145             return jim_mktype_names[i];
 146     }
 147     return "(unknown type)";
 148 }
 149
 150 static Jim_Obj *JimFromMkDescription(Jim_Interp *interp, const char *descr, const char **endPtr)
 151 {
 152     Jim_Obj *result;
 153     const char *delim;
 154
 155     result = Jim_NewListObj(interp, NULL, 0);
 156     for (;;) {
 157         if (*descr == ']') {
 158             descr++;
 159             break;
 160         }
 161         else if (*descr == '\0')
 162             break;
 163         else if (*descr == ',')
 164             descr++;
 165
 166         delim = strpbrk(descr, ",:[]");
 167         /* JimPanic((!delim, "Invalid Metakit description string")); */
 168
 169         Jim_ListAppendElement(interp, result,
 170             Jim_NewStringObj(interp, descr, delim - descr));
 171
 172         if (delim[0] == '[') {
 173             Jim_ListAppendElement(interp, result,
 174                 JimFromMkDescription(interp, delim + 1, &descr));
 175         }
 176         else if (delim[0] == ':') {
 177             Jim_ListAppendElement(interp, result,
 178                 Jim_NewStringObj(interp, JimMkTypeName(delim[1]), -1));
 179             descr = delim + 2;
 180         }
 181         else {
 182             /* Seems that Metakit never generates descriptions without type
 183              * tags, but let's handle this just to be safe
 184              */
 185
 186             Jim_ListAppendElement(interp, result,
 187                 Jim_NewStringObj(interp, JimMkTypeName(MK_PROPERTY_STRING), -1));
 188         }
 189     }
 190
 191     if (endPtr)
 192         *endPtr = descr;
 193     return result;
 194 }
 195
 196 /* This allocates the buffer once per user call and stores it in a static
 197  * variable. Recursive calls are distinguished by descrPtr == NULL.
 198  */
 199 static int JimToMkDescription(Jim_Interp *interp, Jim_Obj *descrObj, char **descrPtr)
 200 {
 201     static char *descr, *outPtr;
 202     static int bufSize;
 203
 204     #define ENLARGE(size) do {                                   \
 205         if ((descr - outPtr) + (size) > bufSize) {               \
 206             bufSize = max(2*bufSize, (descr - outPtr) + (size)); \
 207             descr = (char *)Jim_Realloc(descr, bufSize);         \
 208         }                                                        \
 209     } while(0)
 210
 211     int i, count;
 212     Jim_Obj *name, *struc;
 213
 214     const char *rep;
 215     int len;
 216
 217     count = Jim_ListLength(interp, descrObj);
 218     if (count % 2) {
 219         Jim_SetResultString(interp,
 220             "view description must have an even number of elements", -1);
 221         return JIM_ERR;
 222     }
 223
 224     if (descrPtr) {
 225         descr = (char *)Jim_Alloc(bufSize = JIM_MK_DESCR_LEN);
 226         outPtr = descr;
 227     }
 228
 229     for (i = 0; i < count; i += 2) {
 230         Jim_ListIndex(interp, descrObj, i, &name, 0);
 231         Jim_ListIndex(interp, descrObj, i + 1, &struc, 0);
 232
 233         if (JimCheckMkName(interp, name, NULL) != JIM_OK)
 234             goto err;
 235
 236         rep = Jim_GetString(name, &len);
 237         ENLARGE(len + 3); /* At least :T, or [], */
 238         memcpy(outPtr, rep, len);
 239         outPtr += len;
 240
 241         if (Jim_ListLength(interp, struc) == 1) {
 242             int idx;
 243
 244             if (Jim_GetEnum(interp, struc, jim_mktype_names, &idx,
 245                     "property type", JIM_ERRMSG | JIM_ENUM_ABBREV) != JIM_OK)
 246                 goto err;
 247
 248             *outPtr++ = ':';
 249             *outPtr++ = jim_mktype_types[idx];
 250         }
 251         else {
 252             *outPtr++ = '[';
 253
 254             if (JimToMkDescription(interp, struc, NULL) != JIM_OK)
 255                 goto err;
 256
 257             ENLARGE(2); /* bracket, comma */
 258             *outPtr++ = ']';
 259         }
 260
 261         *outPtr++ = ',';
 262     }
 263     *(--outPtr) = '\0';
 264
 265     #undef ENLARGE
 266
 267     if (descrPtr) {
 268         *descrPtr = (char *)Jim_Realloc(descr, strlen(descr) + 1);
 269         descr = NULL; /* Safety measure */
 270     }
 271
 272     return JIM_OK;
 273
 274   err:
 275
 276     if (descrPtr)
 277         Jim_Free(descr);
 278
 279     return JIM_ERR;
 280 }
 281
 282 static Jim_Obj *JimGetMkValue(Jim_Interp *interp, c4_Cursor cur, const c4_Property &prop)
 283 {
 284     switch (prop.Type()) {
 285         case MK_PROPERTY_INT:
 286             return Jim_NewIntObj(interp, ((c4_IntProp &)prop).Get(*cur));
 287         case MK_PROPERTY_LONG:
 288             return Jim_NewIntObj(interp, ((c4_LongProp &)prop).Get(*cur));
 289         case MK_PROPERTY_FLOAT:
 290             return Jim_NewDoubleObj(interp, ((c4_FloatProp &)prop).Get(*cur));
 291         case MK_PROPERTY_DOUBLE:
 292             return Jim_NewDoubleObj(interp, ((c4_DoubleProp &)prop).Get(*cur));
 293         case MK_PROPERTY_STRING:
 294             return Jim_NewStringObj(interp, ((c4_StringProp &)prop).Get(*cur), -1);
 295         case MK_PROPERTY_VIEW:
 296             return JimNewViewObj(interp, ((c4_ViewProp &)prop).Get(*cur));
 297
 298         case MK_PROPERTY_BINARY:
 299             /* FIXME */
 300         default:
 301             /* FIXME Something more meaningful here? */
 302             return Jim_NewEmptyStringObj(interp);
 303     }
 304 }
 305
 306 static int JimSetMkValue(Jim_Interp *interp, c4_Cursor cur, const c4_Property &prop, Jim_Obj *obj)
 307 {
 308     switch (prop.Type()) {
 309         case MK_PROPERTY_INT: {
 310             jim_wide value;
 311
 312             if (Jim_GetWide(interp, obj, &value) != JIM_OK)
 313                 return JIM_ERR;
 314
 315             ((c4_IntProp &)prop).Set(*cur, value);
 316             return JIM_OK;
 317         }
 318         case MK_PROPERTY_LONG: {
 319             jim_wide value;
 320
 321             if (Jim_GetWide(interp, obj, &value) != JIM_OK)
 322                 return JIM_ERR;
 323
 324             ((c4_LongProp &)prop).Set(*cur, value);
 325             return JIM_OK;
 326         }
 327         case MK_PROPERTY_FLOAT: {
 328             double value;
 329
 330             if (Jim_GetDouble(interp, obj, &value) != JIM_OK)
 331                 return JIM_ERR;
 332
 333             ((c4_FloatProp &)prop).Set(*cur, value);
 334             return JIM_OK;
 335         }
 336         case MK_PROPERTY_DOUBLE: {
 337             double value;
 338
 339             if (Jim_GetDouble(interp, obj, &value) != JIM_OK)
 340                 return JIM_ERR;
 341
 342             ((c4_DoubleProp &)prop).Set(*cur, value);
 343             return JIM_OK;
 344         }
 345         case MK_PROPERTY_STRING: {
 346             int len;
 347             const char *rep;
 348
 349             rep = Jim_GetString(obj, &len);
 350             if (len != (int)strlen(rep)) {
 351                 Jim_SetResultString(interp, "null characters are not allowed in Metakit strings", -1);
 352                 return JIM_ERR;
 353             }
 354
 355             ((c4_StringProp &)prop).Set(*cur, rep);
 356             return JIM_OK;
 357         }
 358         case MK_PROPERTY_VIEW: {
 359             c4_View value;
 360
 361             if (JimGetView(interp, obj, &value) != JIM_OK)
 362                 return JIM_ERR;
 363
 364             ((c4_ViewProp &)prop).Set(*cur, value);
 365         }
 366         case MK_PROPERTY_BINARY:
 367             /* FIXME */
 368         default:
 369             Jim_SetResultString(interp, "unsupported Metakit type", -1);
 370             return JIM_ERR;
 371     }
 372 }
 373
 374 static int JimPipelineBoundary(int argc, Jim_Obj *const *argv) {
 375     const char *rep;
 376     int pipe, len;
 377
 378     for (pipe = 0; pipe < argc; pipe++) {
 379         rep = Jim_GetString(argv[pipe], &len);
 380         if (len == 1 && rep[0] == '|')
 381             break;
 382     }
 383     return pipe;
 384 }
 385
 386 /* -------------------------------------------------------------------------
 387  * Property object
 388  * ------------------------------------------------------------------------- */
 389
 390 #define JimPropertyValue(o) ((c4_Property *)((o)->internalRep.ptr))
 391
 392 static void FreePropertyInternalRep(Jim_Interp *interp, Jim_Obj *obj)
 393 {
 394     delete JimPropertyValue(obj);
 395 }
 396
 397 static void DupPropertyInternalRep(Jim_Interp *interp, Jim_Obj *oldObj, Jim_Obj *newObj)
 398 {
 399     newObj->internalRep.ptr = new c4_Property(*JimPropertyValue(oldObj));
 400     newObj->typePtr = oldObj->typePtr;
 401 }
 402
 403 static void UpdateStringOfProperty(Jim_Obj* obj)
 404 {
 405     const char *name = JimPropertyValue(obj)->Name();
 406     int len = strlen(name);
 407
 408     obj->bytes = (char *) Jim_Alloc(len + 1);
 409     memcpy(obj->bytes, name, len + 1);
 410     obj->length = len;
 411 }
 412
 413 static Jim_ObjType propertyObjType = {
 414     "mk.property",
 415     FreePropertyInternalRep,
 416     DupPropertyInternalRep,
 417     UpdateStringOfProperty,
 418     JIM_TYPE_NONE
 419 };
 420
 421 static int JimGetProperty(Jim_Interp *interp, Jim_Obj *obj, c4_View view, const char *name, const c4_Property **propPtr)
 422 {
 423     int index;
 424
 425     if (obj->typePtr == &propertyObjType) {
 426         index = view.FindProperty(JimPropertyValue(obj)->GetId());
 427     }
 428     else {
 429         if (JimCheckMkName(interp, obj, name) != JIM_OK)
 430             return JIM_ERR;
 431         index = view.FindPropIndexByName(Jim_String(obj));
 432     }
 433
 434     if (index != -1) {
 435         *propPtr = &view.NthProperty(index);
 436         return JIM_OK;
 437     }
 438     else {
 439         Jim_SetResultFormatted(interp, "%s \"%#s\" does not exist",
 440             name ? name : "property", obj);
 441         return JIM_ERR;
 442     }
 443 }
 444
 445 static int JimGetPropertyTyped(Jim_Interp *interp, Jim_Obj *obj, char type, const c4_Property **propPtr)
 446 {
 447     c4_Property *prop;
 448
 449     if (obj->typePtr == &propertyObjType) {
 450         if (JimPropertyValue(obj)->Type() != type) {
 451             /* coerce the property type */
 452
 453             prop = new c4_Property(type, JimPropertyValue(obj)->Name());
 454             delete JimPropertyValue(obj);
 455             obj->internalRep.ptr = prop;
 456         }
 457     }
 458     else {
 459         if (JimCheckMkName(interp, obj, NULL) != JIM_OK)
 460             return JIM_ERR;
 461
 462         prop = new c4_Property(type, Jim_String(obj));
 463
 464         Jim_FreeIntRep(interp, obj);
 465         obj->typePtr = &propertyObjType;
 466         obj->internalRep.ptr = (void *)prop;
 467     }
 468
 469     *propPtr = JimPropertyValue(obj);
 470     return JIM_OK;
 471 }
 472
 473 static int JimGetNewProperty(Jim_Interp *interp, Jim_Obj *obj, c4_View view, char type, const c4_Property **propPtr)
 474 {
 475     const c4_Property *newp, *prop;
 476
 477     if (JimGetPropertyTyped(interp, obj, type, &newp) != JIM_OK)
 478         return JIM_ERR;
 479
 480     prop = &view.NthProperty(view.AddProperty(*newp));
 481
 482     if (prop->Type() != newp->Type()) {
 483         Jim_SetResultFormatted(interp, "property \"%#s\" is %s, not %s",
 484             obj, JimMkTypeName(prop->Type()), JimMkTypeName(newp->Type()));
 485         return JIM_ERR;
 486     }
 487
 488     *propPtr = prop;
 489     return JIM_OK;
 490 }
 491
 492 static int JimGetProperties(Jim_Interp *interp, int objc, Jim_Obj *const *objv, c4_View view, c4_View *propsPtr)
 493 {
 494     int i;
 495     const c4_Property *prop;
 496     c4_View props;
 497
 498     for (i = 0; i < objc; i++) {
 499         if (JimGetProperty(interp, objv[i], view, NULL, &prop) != JIM_OK)
 500             return JIM_ERR;
 501
 502         props.AddProperty(*prop);
 503     }
 504
 505     *propsPtr = props;
 506     return JIM_OK;
 507 }
 508
 509 static Jim_Obj *JimNewPropertyObj(Jim_Interp *interp, c4_Property prop)
 510 {
 511     Jim_Obj *obj;
 512
 513     obj = Jim_NewObj(interp);
 514     obj->typePtr = &propertyObjType;
 515     obj->bytes = NULL;
 516     obj->internalRep.ptr = new c4_Property(prop);
 517     return obj;
 518 }
 519
 520 /* -------------------------------------------------------------------------
 521  * Cursor object
 522  * ------------------------------------------------------------------------- */
 523
 524 /* Position ---------------------------------------------------------------- */
 525
 526 /* A normal position if endFlag == 0; otherwise an offset from end+1 (!) */
 527 typedef struct MkPosition {
 528     int index;
 529     int endFlag;
 530 } MkPosition;
 531
 532 /* This is mostly the same as SetIndexFromAny, but preserves more information
 533  * and allows multiple [+-]integer parts.
 534  */
 535 static int GetPosition(Jim_Interp *interp, Jim_Obj *obj, MkPosition *posPtr)
 536 {
 537     MkPosition pos;
 538     const char *rep;
 539     char *end;
 540     int sign, offset;
 541
 542     rep = Jim_String(obj);
 543
 544     if (strncmp(rep, "end", 3) == 0) {
 545         pos.endFlag = 1;
 546         pos.index = -1;
 547
 548         rep += 3;
 549     }
 550     else {
 551         pos.endFlag = 0;
 552         pos.index = strtol(rep, &end, 10);
 553         if (end == rep)
 554             goto err;
 555
 556         rep = end;
 557     }
 558
 559     while ((rep[0] == '+') || (rep[0] == '-')) {
 560         sign = (rep[0] == '+' ? 1 : -1);
 561         rep++;
 562
 563         offset = strtol(rep, &end, 10);
 564         if (end == rep)
 565             goto err;
 566
 567         pos.index += sign * offset;
 568         rep = end;
 569     }
 570
 571     while (isspace(UCHAR(*rep)))
 572         rep++;
 573     if (*rep != '\0')
 574         goto err;
 575
 576     *posPtr = pos;
 577     return JIM_OK;
 578
 579   err:
 580     Jim_SetResultFormatted(interp, "expected cursor position but got \"%#s\"", obj);
 581     return JIM_ERR;
 582 }
 583
 584 static int PositionIndex(const MkPosition *posPtr, c4_View view)
 585 {
 586     if (posPtr->endFlag)
 587         return view.GetSize() + posPtr->index;
 588     else
 589         return posPtr->index;
 590 }
 591
 592 static int JimGetPosition(Jim_Interp *interp, Jim_Obj *obj, c4_View view, int *indexPtr)
 593 {
 594     MkPosition pos;
 595
 596     if (GetPosition(interp, obj, &pos) != JIM_OK)
 597         return JIM_ERR;
 598
 599     *indexPtr = PositionIndex(&pos, view);
 600     return JIM_OK;
 601 }
 602
 603 /* Cursor type ------------------------------------------------------------- */
 604
 605 typedef struct MkCursor {
 606     MkPosition pos;
 607     Jim_Obj *viewObj;
 608 } MkCursor;
 609
 610 #define JimCursorValue(obj) ((MkCursor *)(obj->internalRep.ptr))
 611 static void FreeCursorInternalRep(Jim_Interp *interp, Jim_Obj *obj)
 612 {
 613     Jim_DecrRefCount(interp, JimCursorValue(obj)->viewObj);
 614     Jim_Free(obj->internalRep.ptr);
 615 }
 616
 617 static void DupCursorInternalRep(Jim_Interp *interp, Jim_Obj *oldObj, Jim_Obj *newObj)
 618 {
 619     newObj->internalRep.ptr = Jim_Alloc(sizeof(MkCursor));
 620     *JimCursorValue(newObj) = *JimCursorValue(oldObj);
 621     Jim_IncrRefCount(JimCursorValue(oldObj)->viewObj);
 622
 623     newObj->typePtr = oldObj->typePtr;
 624 }
 625
 626 static void UpdateStringOfCursor(Jim_Obj *obj)
 627 {
 628     char buf[JIM_CURSOR_SPACE + 1];
 629     MkCursor *curPtr = JimCursorValue(obj);
 630     int idx, len;
 631
 632     len = snprintf(buf, JIM_CURSOR_SPACE + 1, "%s!", Jim_String(curPtr->viewObj));
 633
 634     if (curPtr->pos.endFlag) {
 635         idx = curPtr->pos.index + 1;
 636         if (idx == 0)
 637             len += snprintf(buf + len, JIM_CURSOR_SPACE + 1 - len, "end");
 638         else
 639             len += snprintf(buf + len, JIM_CURSOR_SPACE + 1 - len, "end%+d", idx);
 640     }
 641     else {
 642         len += snprintf(buf + len, JIM_CURSOR_SPACE + 1 - len, "%d",
 643             curPtr->pos.index);
 644     }
 645
 646     obj->bytes = (char *)Jim_Alloc(len + 1);
 647     memcpy(obj->bytes, buf, len + 1);
 648     obj->length = len;
 649 }
 650
 651 static Jim_ObjType cursorObjType = {
 652     "mk.cursor",
 653     FreeCursorInternalRep,
 654     DupCursorInternalRep,
 655     UpdateStringOfCursor,
 656     JIM_TYPE_REFERENCES
 657 };
 658
 659 static int SetCursorFromAny(Jim_Interp *interp, Jim_Obj *obj)
 660 {
 661     const char *rep, *delim;
 662     int len;
 663     Jim_Obj *posObj;
 664     MkCursor cur;
 665
 666     rep = Jim_GetString(obj, &len);
 667     delim = strrchr(rep, '!');
 668
 669     if (!delim) {
 670         Jim_SetResultFormatted(interp, "expected cursor but got \"%#s\"", obj);
 671         return JIM_ERR;
 672     }
 673
 674     cur.viewObj = Jim_NewStringObj(interp, rep, delim - rep);
 675     posObj = Jim_NewStringObj(interp, delim + 1, len - (delim - rep) - 1);
 676
 677     if (GetPosition(interp, posObj, &cur.pos) != JIM_OK) {
 678         Jim_FreeNewObj(interp, posObj);
 679         Jim_FreeNewObj(interp, cur.viewObj);
 680         return JIM_ERR;
 681     }
 682
 683     Jim_FreeIntRep(interp, obj);
 684     Jim_FreeNewObj(interp, posObj);
 685     Jim_IncrRefCount(cur.viewObj);
 686
 687     obj->typePtr = &cursorObjType;
 688     obj->internalRep.ptr = Jim_Alloc(sizeof(MkCursor));
 689     *JimCursorValue(obj) = cur;
 690
 691     return JIM_OK;
 692 }
 693
 694 /* Functions --------------------------------------------------------------- */
 695
 696 static int JimCursorPos(Jim_Interp *interp, Jim_Obj *obj, Jim_Obj **posObjPtr)
 697 {
 698     if (obj->typePtr != &cursorObjType && SetCursorFromAny(interp, obj) != JIM_OK)
 699         return JIM_ERR;
 700
 701     *posObjPtr = Jim_NewStringObj(interp, strrchr(Jim_String(obj), '!') + 1, -1);
 702     return JIM_OK;
 703 }
 704
 705 static int JimGetCursorView(Jim_Interp *interp, Jim_Obj *obj, Jim_Obj **viewObjPtr)
 706 {
 707     if (obj->typePtr != &cursorObjType && SetCursorFromAny(interp, obj) != JIM_OK)
 708         return JIM_ERR;
 709
 710     *viewObjPtr = JimCursorValue(obj)->viewObj;
 711     return JIM_OK;
 712 }
 713
 714 static int JimGetCursor(Jim_Interp *interp, Jim_Obj *obj, c4_Cursor *curPtr)
 715 {
 716     c4_View view;
 717
 718     if (obj->typePtr != &cursorObjType && SetCursorFromAny(interp, obj) != JIM_OK)
 719         return JIM_ERR;
 720     if (JimGetView(interp, JimCursorValue(obj)->viewObj, &view) != JIM_OK)
 721         return JIM_ERR;
 722
 723     if (curPtr)
 724         *curPtr = &view[PositionIndex(&JimCursorValue(obj)->pos, view)];
 725     return JIM_OK;
 726 }
 727
 728 static int JimIncrCursor(Jim_Interp *interp, Jim_Obj *obj, int offset)
 729 {
 730     /* JimPanic((Jim_IsShared(obj), "JimIncrCursor called with shared object")) */
 731
 732     if (obj->typePtr != &cursorObjType && SetCursorFromAny(interp, obj) != JIM_OK)
 733         return JIM_ERR;
 734
 735     Jim_InvalidateStringRep(obj);
 736     JimCursorValue(obj)->pos.index += offset;
 737     return JIM_OK;
 738 }
 739
 740 static int JimSeekCursor(Jim_Interp *interp, Jim_Obj *obj, Jim_Obj *posObj)
 741 {
 742     /* JimPanic((Jim_IsShared(obj), "JimSeekCursor called with shared object")) */
 743
 744     if (obj->typePtr != &cursorObjType && SetCursorFromAny(interp, obj) != JIM_OK)
 745         return JIM_ERR;
 746
 747     Jim_InvalidateStringRep(obj);
 748     return GetPosition(interp, posObj, &JimCursorValue(obj)->pos);
 749 }
 750
 751 static int JimCheckCursor(Jim_Interp *interp, Jim_Obj *curObj, int flags)
 752 {
 753     static c4_View nullView;
 754
 755     c4_Cursor cur = &nullView[0];
 756     int size;
 757
 758     if (JimGetCursor(interp, curObj, &cur) != JIM_OK)
 759         return JIM_ERR;
 760     size = (*cur).Container().GetSize();
 761
 762     if ((flags & JIM_CURSOR_GET) && (cur._index < 0 || cur._index >= size)) {
 763         if (flags & JIM_ERRMSG) {
 764             Jim_SetResultFormatted(interp,
 765                 "cursor \"%#s\" does not point to an existing row", curObj);
 766         }
 767         return JIM_ERR;
 768     }
 769     else if ((flags & JIM_CURSOR_SET) && cur._index < 0) {
 770         if (flags & JIM_ERRMSG) {
 771             Jim_SetResultFormatted(interp,
 772                 "cursor \"%#s\" points before start of view", curObj);
 773         }
 774         return JIM_ERR;
 775     }
 776     else if ((flags & JIM_CURSOR_INSERT) && (cur._index < 0 || cur._index > size)) {
 777         if (flags & JIM_ERRMSG) {
 778             Jim_SetResultFormatted(interp,
 779                 "cursor \"%#s\" does not point to a valid insert position", curObj);
 780         }
 781         return JIM_ERR;
 782     }
 783
 784     return JIM_OK;
 785 }
 786
 787 /* Records ----------------------------------------------------------------- */
 788
 789 static int cursor_cmd_get(Jim_Interp *interp, int argc, Jim_Obj *const *argv)
 790 {
 791     c4_View view;
 792     c4_Cursor cur = &view[0];
 793
 794     if (JimGetCursor(interp, argv[0], &cur) != JIM_OK)
 795         return JIM_ERR;
 796     if (JimCheckCursor(interp, argv[0], JIM_ERRMSG | JIM_CURSOR_GET) != JIM_OK)
 797         return JIM_ERR;
 798
 799     view = (*cur).Container();
 800
 801     if (argc == 1) { /* Return all properties */
 802         int i, count;
 803         Jim_Obj *result;
 804
 805         result = Jim_NewListObj(interp, NULL, 0);
 806         count = view.NumProperties();
 807
 808         for (i = 0; i < count; i++) {
 809             c4_Property prop = view.NthProperty(i);
 810
 811             Jim_ListAppendElement(interp, result, JimNewPropertyObj(interp, prop));
 812             Jim_ListAppendElement(interp, result, JimGetMkValue(interp, cur, prop));
 813         }
 814
 815         Jim_SetResult(interp, result);
 816         return JIM_OK;
 817     }
 818     else { /* Return a single property */
 819         const c4_Property *propPtr;
 820         int pipe;
 821
 822         pipe = JimPipelineBoundary(argc, argv);
 823         if (pipe == 2) {
 824             /* No type annotation, existing property */
 825             if (JimGetProperty(interp, argv[1], view, NULL, &propPtr) != JIM_OK)
 826                 return JIM_ERR;
 827         }
 828         else if (pipe == 3) {
 829             /* Explicit type annotation; the property may be new */
 830             int idx;
 831
 832             if (Jim_GetEnum(interp, argv[1], jim_mktype_options, &idx,
 833                     "property type", JIM_ERRMSG | JIM_ENUM_ABBREV) != JIM_OK)
 834                 return JIM_ERR;
 835             if (JimGetNewProperty(interp, argv[2], view, jim_mktype_types[idx], &propPtr) != JIM_OK)
 836                 return JIM_ERR;
 837         }
 838         else {
 839             Jim_WrongNumArgs(interp, 0, NULL, "cursor get ?-type? ?prop?");
 840             return JIM_ERR;
 841         }
 842
 843         Jim_SetResult(interp, JimGetMkValue(interp, cur, *propPtr));
 844
 845         if (pipe == argc)
 846             return JIM_OK;
 847         else
 848             return Jim_EvalObjPrefix(interp, Jim_GetResult(interp), argc - pipe - 1, argv + pipe + 1);
 849     }
 850 }
 851
 852 static int cursor_cmd_set(Jim_Interp *interp, int argc, Jim_Obj *const *argv)
 853 {
 854     c4_View view;
 855     c4_Cursor cur = &view[0];
 856     const c4_Property *propPtr;
 857     int i, oldSize;
 858
 859     if (JimGetCursor(interp, argv[0], &cur) != JIM_OK)
 860         return JIM_ERR;
 861     if (JimCheckCursor(interp, argv[0], JIM_ERRMSG | JIM_CURSOR_SET) != JIM_OK)
 862         return JIM_ERR;
 863
 864     view = (*cur).Container();
 865     oldSize = view.GetSize();
 866
 867     if (cur._index >= oldSize)
 868         view.SetSize(cur._index + 1);
 869
 870     if (argc == 2) {
 871         /* Update everything except subviews from a dictionary in argv[1].
 872          * No new properties are permitted.
 873          */
 874
 875         int objc;
 876         Jim_Obj **objv;
 877
 878         if (Jim_DictPairs(interp, argv[1], &objv, &objc) != JIM_OK)
 879             goto err;
 880
 881         for (i = 0; i < objc; i += 2) {
 882             if (JimGetProperty(interp, objv[i], view, NULL, &propPtr) != JIM_OK ||
 883                 JimSetMkValue(interp, cur, *propPtr, objv[i+1]) != JIM_OK)
 884             {
 885                 Jim_Free(objv);
 886                 goto err;
 887             }
 888         }
 889     }
 890     else {
 891         /* Update everything from argv[1..]. New properties are permitted if
 892          * explicitly typed.
 893          */
 894
 895         for (i = 1; i < argc; i += 2) {
 896             if (Jim_String(argv[i])[0] == '-') {
 897                 int idx;
 898
 899                 if (i + 2 >= argc) {
 900                     Jim_WrongNumArgs(interp, 2, argv, "?-type? prop value ?...?");
 901                     goto err;
 902                 }
 903
 904                 if (Jim_GetEnum(interp, argv[i], jim_mktype_options, &idx,
 905                         "property type", JIM_ERRMSG | JIM_ENUM_ABBREV) != JIM_OK)
 906                     goto err;
 907                 if (JimGetNewProperty(interp, argv[i+1], view, jim_mktype_types[idx], &propPtr) != JIM_OK)
 908                     goto err;
 909                 i++;
 910             }
 911             else {
 912                 if (i + 1 >= argc) {
 913                     Jim_WrongNumArgs(interp, 2, argv, "?-type? prop value ?...?");
 914                     goto err;
 915                 }
 916
 917                 if (JimGetProperty(interp, argv[i], view, NULL, &propPtr) != JIM_OK)
 918                     goto err;
 919             }
 920
 921             if (JimSetMkValue(interp, cur, *propPtr, argv[i+1]) != JIM_OK)
 922                 goto err;
 923         }
 924     }
 925
 926     return JIM_OK;
 927
 928   err:
 929     view.SetSize(oldSize);
 930     return JIM_ERR;
 931 }
 932
 933 static int cursor_cmd_insert(Jim_Interp *interp, int argc, Jim_Obj *const *argv)
 934 {
 935     c4_View view;
 936     c4_Cursor cur = &view[0];
 937     jim_wide count;
 938
 939     if (JimGetCursor(interp, argv[0], &cur) != JIM_OK)
 940         return JIM_ERR;
 941     if (JimCheckCursor(interp, argv[0], JIM_ERRMSG | JIM_CURSOR_INSERT) != JIM_OK)
 942         return JIM_ERR;
 943
 944     view = (*cur).Container();
 945
 946     if (argc == 1)
 947         count = 1;
 948     else {
 949         if (Jim_GetWide(interp, argv[1], &count) != JIM_OK)
 950             return JIM_ERR;
 951     }
 952
 953     if (count > 0) {
 954         c4_Row empty;
 955         view.InsertAt(cur._index, empty, (int)count);
 956     }
 957
 958     Jim_SetEmptyResult(interp);
 959     return JIM_OK;
 960 }
 961
 962 static int cursor_cmd_remove(Jim_Interp *interp, int argc, Jim_Obj *const *argv)
 963 {
 964     c4_View view;
 965     c4_Cursor cur = &view[0];
 966     int pos;
 967     jim_wide count;
 968
 969     if (JimGetCursor(interp, argv[0], &cur) != JIM_OK)
 970         return JIM_ERR;
 971     if (JimCheckCursor(interp, argv[0], JIM_ERRMSG | JIM_CURSOR_SET) != JIM_OK)
 972         return JIM_ERR;
 973
 974     view = (*cur).Container();
 975     pos = cur._index;
 976
 977     if (argc == 1)
 978         count = 1;
 979     else {
 980         if (Jim_GetWide(interp, argv[1], &count) != JIM_OK)
 981             return JIM_ERR;
 982     }
 983
 984     if (pos + count < view.GetSize())
 985         count = view.GetSize() - pos;
 986
 987     if (pos < view.GetSize())
 988         view.RemoveAt(pos, (int)count);
 989
 990     return JIM_OK;
 991 }
 992
 993 /* Attributes -------------------------------------------------------------- */
 994
 995 static int cursor_cmd_view(Jim_Interp *interp, int argc, Jim_Obj *const *argv)
 996 {
 997     Jim_Obj *viewObj;
 998
 999     if (JimGetCursorView(interp, argv[0], &viewObj) != JIM_OK)
1000         return JIM_ERR;
1001
1002     JimPinView(interp, viewObj);
1003     Jim_SetResult(interp, viewObj);
1004     return JIM_OK;
1005 }
1006
1007 /* Positioning ------------------------------------------------------------- */
1008
1009 static int cursor_cmd_tell(Jim_Interp *interp, int argc, Jim_Obj *const *argv)
1010 {
1011     if (argc == 1) {
1012         Jim_Obj *result;
1013
1014         if (JimCursorPos(interp, argv[0], &result) != JIM_OK)
1015             return JIM_ERR;
1016         Jim_SetResult(interp, result);
1017     }
1018     else {
1019         static c4_View nullView;
1020         c4_Cursor cur = &nullView[0];
1021
1022         if (!Jim_CompareStringImmediate(interp, argv[0], "-absolute")) {
1023             Jim_SetResultFormatted(interp,
1024                 "bad option \"%#s\": must be -absolute", argv[0]);
1025             return JIM_ERR;
1026         }
1027
1028         if (JimGetCursor(interp, argv[1], &cur) != JIM_OK)
1029             return JIM_ERR;
1030
1031         Jim_SetResultInt(interp, cur._index);
1032     }
1033
1034     return JIM_OK;
1035 }
1036
1037 static int cursor_cmd_validfor(Jim_Interp *interp, int argc, Jim_Obj *const *argv)
1038 {
1039     static const char *options[] = {
1040         "get", "set", "insert", "remove", 0
1041     };
1042     static int optflags[] = {
1043         JIM_CURSOR_GET,
1044         JIM_CURSOR_SET,
1045         JIM_CURSOR_INSERT,
1046         JIM_CURSOR_SET
1047     };
1048
1049     int idx;
1050
1051     if (argc == 1)
1052         idx = 0;
1053     else {
1054         if (Jim_GetEnum(interp, argv[0], options, &idx, NULL,
1055                 JIM_ERRMSG | JIM_ENUM_ABBREV) != JIM_OK)
1056             return JIM_ERR;
1057     }
1058
1059     if (JimGetCursor(interp, argv[argc-1], NULL) != JIM_OK)
1060         return JIM_ERR;
1061
1062     Jim_SetResultBool(interp, JimCheckCursor(interp, argv[argc-1], optflags[idx]) == JIM_OK);
1063     return JIM_OK;
1064 }
1065
1066 static int cursor_cmd_seek(Jim_Interp *interp, int argc, Jim_Obj *const *argv)
1067 {
1068     Jim_Obj *curObj;
1069
1070     curObj = Jim_GetVariable(interp, argv[0], JIM_ERRMSG | JIM_UNSHARED);
1071     if (curObj == NULL)
1072         return JIM_ERR;
1073
1074     if (JimSeekCursor(interp, curObj, argv[1]) != JIM_OK)
1075         return JIM_ERR;
1076
1077     Jim_SetResult(interp, curObj);
1078     return JIM_OK;
1079 }
1080
1081 static int cursor_cmd_incr(Jim_Interp *interp, int argc, Jim_Obj *const *argv)
1082 {
1083     Jim_Obj *curObj;
1084     jim_wide offset;
1085
1086     if (argc == 1)
1087         offset = 1;
1088     else {
1089         if (Jim_GetWide(interp, argv[1], &offset) != JIM_OK)
1090             return JIM_ERR;
1091     }
1092
1093     curObj = Jim_GetVariable(interp, argv[0], JIM_ERRMSG | JIM_UNSHARED);
1094     if (curObj == NULL)
1095         return JIM_ERR;
1096
1097     if (JimIncrCursor(interp, curObj, (int)offset) != JIM_OK)
1098         return JIM_ERR;
1099
1100     Jim_SetResult(interp, curObj);
1101     return JIM_OK;
1102 }
1103
1104 /* Command table ----------------------------------------------------------- */
1105
1106 static const jim_subcmd_type cursor_command_table[] = {
1107
1108     /* Records */
1109
1110     {   "get", "cur ?-type? ?prop?",
1111         cursor_cmd_get,
1112         1, -1,
1113         0,
1114         /*"Get the whole record or a specific property at the cursor"*/
1115     },
1116     {   "set", "cur [dict | ?-type? field value ?...?]",
1117         cursor_cmd_set,
1118         1, -1,
1119         0,
1120         /*"Update the record at the cursor"*/
1121     },
1122     {   "insert", "cur ?count?",
1123         cursor_cmd_insert,
1124         1, 2,
1125         0,
1126         /*"Insert a specified number of empty rows at the cursor (default 1)"*/
1127     },
1128     {   "remove", "cur ?count?",
1129         cursor_cmd_remove,
1130         1, 2,
1131         0,
1132         /*"Remove a specified number of rows at the cursor (default 1)"*/
1133     },
1134
1135     /* Attributes */
1136
1137     {   "view", "cur",
1138         cursor_cmd_view,
1139         1, 1,
1140         0,
1141         /*"Get the view the cursor points into"*/
1142     },
1143
1144     /* Positioning */
1145
1146     {   "tell", "?-absolute? cur",
1147         cursor_cmd_tell,
1148         1, 2,
1149         0,
1150         /*"Get the position of the cursor"*/
1151     },
1152     {   "validfor", "?command? cur",
1153         cursor_cmd_validfor,
1154         1, 2,
1155         0,
1156         /*"Checks if the cursor is valid for get (default), set or insert commands"*/
1157     },
1158     {   "seek", "curVar index",
1159         cursor_cmd_seek,
1160         2, 2,
1161         0,
1162         /*"Seek to the specified index in the view"*/
1163     },
1164     {   "incr", "curVar ?offset?",
1165         cursor_cmd_incr,
1166         1, 2,
1167         0,
1168         /*"Move the cursor offset records from its current position (default 1)"*/
1169     },
1170
1171     { 0 }
1172 };
1173
1174 static int JimCursorCommand(Jim_Interp *interp, int argc, Jim_Obj *const *argv)
1175 {
1176     Jim_Obj *cmdObj;
1177
1178     if (argc < 2) {
1179         Jim_WrongNumArgs(interp, 1, argv, "command ...");
1180         return JIM_ERR;
1181     }
1182
1183     cmdObj = Jim_NewStringObj(interp, "cursor ", -1);
1184     Jim_AppendObj(interp, cmdObj, argv[1]);
1185
1186     if (Jim_GetCommand(interp, cmdObj, 0) != NULL)
1187         return Jim_EvalObjPrefix(interp, cmdObj, argc - 2, argv + 2);
1188     else {
1189         Jim_FreeNewObj(interp, cmdObj);
1190         return Jim_CallSubCmd(interp,
1191             Jim_ParseSubCmd(interp, cursor_command_table, argc, argv), argc, argv);
1192     }
1193 }
1194
1195 /* -------------------------------------------------------------------------
1196  * View handle
1197  * ------------------------------------------------------------------------- */
1198
1199 /* Views aren't really Jim objects; instead, they are Tk-style commands with
1200  * oo.tcl-like lifetime management. Additionally, all views are initially
1201  * created as one-shot, meaning that they die after one command. Call
1202  * JimPinView to make a view object persistent.
1203  *
1204  * It is valid to rename a view in the Tcl land, but by doing this you take
1205  * the responsibility of destroying the object when it's no longer needed.
1206  * Any cursors that pointed into the view become invalid.
1207  */
1208
1209 static int JimViewSubCmdProc(Jim_Interp *interp, int argc, Jim_Obj *const *argv);
1210 static int JimOneShotViewSubCmdProc(Jim_Interp *interp, int argc, Jim_Obj *const *argv);
1211
1212 /* Unary operations -------------------------------------------------------- */
1213
1214 #define UNOP(name, Method) \
1215 static int view_cmd_##name(Jim_Interp *interp, int argc, Jim_Obj *const *argv)  \
1216 {   \
1217     const c4_View *viewPtr = (const c4_View *)Jim_CmdPrivData(interp);          \
1218     \
1219     Jim_SetResult(interp, JimNewViewObj(interp, viewPtr->Method()));            \
1220     return JIM_OK;                                                              \
1221 }
1222
1223 UNOP(copy, Duplicate)
1224 UNOP(clone, Clone)
1225 UNOP(unique, Unique)
1226
1227 #undef UNOP
1228
1229 static int view_cmd_blocked(Jim_Interp *interp, int argc, Jim_Obj *const *argv)
1230 {
1231     const c4_View *viewPtr = (const c4_View *)Jim_CmdPrivData(interp);
1232
1233     if (viewPtr->GetSize() != 1 ||
1234         strcmp(viewPtr->NthProperty(0).Name(), "_B") != 0 ||
1235         viewPtr->NthProperty(0).Type() != MK_PROPERTY_VIEW)
1236     {
1237         Jim_SetResultString(interp,
1238             "blocked view must have exactly one subview property called _B", -1);
1239         return JIM_ERR;
1240     }
1241
1242     Jim_SetResult(interp, JimNewViewObj(interp, viewPtr->Blocked()));
1243     return JIM_OK;
1244 }
1245
1246 /* Binary operations ------------------------------------------------------- */
1247
1248 #define BINOP(name, Method) \
1249 static int view_cmd_##name(Jim_Interp *interp, int argc, Jim_Obj *const *argv)  \
1250 {   \
1251     const c4_View *viewPtr = (const c4_View *)Jim_CmdPrivData(interp);          \
1252     c4_View otherView;                                                          \
1253     \
1254     if (JimGetView(interp, argv[0], &otherView) != JIM_OK)                      \
1255         return JIM_ERR;                                                         \
1256     \
1257     Jim_SetResult(interp, JimNewViewObj(interp, viewPtr->Method(otherView)));   \
1258     return JIM_OK;                                                              \
1259 }
1260
1261 BINOP(pair, Pair)
1262 BINOP(concat, Concat)
1263 BINOP(product, Product)
1264
1265 BINOP(union, Union)
1266 BINOP(intersect, Intersect)
1267 BINOP(minus, Minus)
1268 BINOP(different, Different)
1269
1270 #undef BINOP
1271
1272 /* Projections ------------------------------------------------------------- */
1273
1274 static int view_cmd_project(Jim_Interp *interp, int argc, Jim_Obj *const *argv)
1275 {
1276     const c4_View *viewPtr = (const c4_View *)Jim_CmdPrivData(interp);
1277     c4_View props;
1278
1279     if (JimGetProperties(interp, argc, argv, *viewPtr, &props) != JIM_OK)
1280         return JIM_ERR;
1281
1282     Jim_SetResult(interp, JimNewViewObj(interp, viewPtr->Project(props)));
1283     return JIM_OK;
1284 }
1285
1286 static int view_cmd_without(Jim_Interp *interp, int argc, Jim_Obj *const *argv)
1287 {
1288     const c4_View *viewPtr = (const c4_View *)Jim_CmdPrivData(interp);
1289     c4_View props;
1290
1291     if (JimGetProperties(interp, argc, argv, *viewPtr, &props) != JIM_OK)
1292         return JIM_ERR;
1293
1294     Jim_SetResult(interp, JimNewViewObj(interp, viewPtr->ProjectWithout(props)));
1295     return JIM_OK;
1296 }
1297
1298 static int view_cmd_range(Jim_Interp *interp, int argc, Jim_Obj *const *argv)
1299 {
1300     const c4_View *viewPtr = (const c4_View *)Jim_CmdPrivData(interp);
1301     int start, end;
1302     jim_wide step;
1303
1304     if (JimGetPosition(interp, argv[0], *viewPtr, &start) != JIM_OK ||
1305         JimGetPosition(interp, argv[1], *viewPtr, &end) != JIM_OK)
1306     {
1307         return JIM_ERR;
1308     }
1309
1310     if (argc == 2)
1311         step = 1;
1312     else if (Jim_GetWide(interp, argv[2], &step) != JIM_OK)
1313         return JIM_ERR;
1314
1315     Jim_SetResult(interp, JimNewViewObj(interp, viewPtr->Slice(start, end + 1, (int)step)));
1316     return JIM_OK;
1317 }
1318
1319 /* Ordering ---------------------------------------------------------------- */
1320
1321 static int view_cmd_sort(Jim_Interp *interp, int argc, Jim_Obj *const *argv)
1322 {
1323     const c4_View *viewPtr = (const c4_View *)Jim_CmdPrivData(interp);
1324     c4_View sortProps, revProps;
1325     const c4_Property *propPtr;
1326     int i, len;
1327
1328     const char *rep;
1329     int reverse;
1330     Jim_Obj *propObj;
1331
1332     /* Special case: property names may be preceded with a dash. Use
1333      * a temporary object in this case.
1334      */
1335
1336     for (i = 0; i < argc; i++) {
1337         propObj = argv[i];
1338
1339         rep = Jim_GetString(argv[i], &len);
1340         reverse = (len > 0 && rep[0] == '-');
1341
1342         if (reverse)
1343             propObj = Jim_NewStringObj(interp, rep + 1, len - 1);
1344
1345         if (JimGetProperty(interp, propObj, *viewPtr, NULL, &propPtr) != JIM_OK) {
1346             if (reverse)
1347                 Jim_FreeNewObj(interp, propObj);
1348             return JIM_ERR;
1349         }
1350
1351         sortProps.AddProperty(*propPtr);
1352         if (reverse) {
1353             revProps.AddProperty(*propPtr);
1354             Jim_FreeNewObj(interp, propObj);
1355         }
1356     }
1357
1358     if (sortProps.GetSize() == 0)
1359         Jim_SetResult(interp, JimNewViewObj(interp, viewPtr->Sort()));
1360     else if (revProps.GetSize() == 0)
1361         Jim_SetResult(interp, JimNewViewObj(interp, viewPtr->SortOn(sortProps)));
1362     else
1363         Jim_SetResult(interp, JimNewViewObj(interp, viewPtr->SortOnReverse(sortProps, revProps)));
1364
1365     return JIM_OK;
1366 }
1367
1368 /* Metakit core seems to be doing something similar for SortOn, but neither
1369  * Ordered nor Hash use it, for unknown reason.
1370  */
1371
1372 static int BubbleProperties(Jim_Interp *interp, c4_View orig, int objc, Jim_Obj *const *objv, c4_View *projPtr)
1373 {
1374     c4_View proj;
1375     const c4_Property *propPtr;
1376     int i, count;
1377
1378     for (i = 0; i < objc; i++) {
1379         if (JimGetProperty(interp, objv[i], orig, NULL, &propPtr) != JIM_OK)
1380             return JIM_ERR;
1381         proj.AddProperty(*propPtr);
1382     }
1383
1384     count = orig.NumProperties();
1385     for (i = 0; i < count; i++)
1386         proj.AddProperty(orig.NthProperty(i));
1387
1388     *projPtr = proj;
1389     return JIM_OK;
1390 }
1391
1392 static int view_cmd_ordered(Jim_Interp *interp, int argc, Jim_Obj *const *argv)
1393 {
1394     const c4_View *viewPtr = (const c4_View *)Jim_CmdPrivData(interp);
1395     c4_View proj;
1396
1397     if (BubbleProperties(interp, *viewPtr, argc, argv, &proj) != JIM_OK)
1398         return JIM_ERR;
1399
1400     Jim_SetResult(interp, JimNewViewObj(interp, proj.Ordered(argc)));
1401     return JIM_OK;
1402 }
1403
1404 static int view_cmd_hash(Jim_Interp *interp, int argc, Jim_Obj *const *argv)
1405 {
1406     const c4_View *viewPtr = (const c4_View *)Jim_CmdPrivData(interp);
1407     c4_View hash, proj;
1408
1409     if (JimGetView(interp, argv[0], &hash) != JIM_OK)
1410         return JIM_ERR;
1411
1412     if (hash.GetSize() != 2 ||
1413         strcmp(hash.NthProperty(0).Name(), "_H") != 0 ||
1414         hash.NthProperty(0).Type() != MK_PROPERTY_INT ||
1415         strcmp(hash.NthProperty(1).Name(), "_R") != 0 ||
1416         hash.NthProperty(1).Type() != MK_PROPERTY_INT) /* Ouch. */
1417     {
1418         Jim_SetResultString(interp,
1419             "hash view must be laid out as {_H integer _R integer}", -1);
1420         return JIM_ERR;
1421     }
1422
1423     if (BubbleProperties(interp, *viewPtr, argc - 1, argv + 1, &proj) != JIM_OK)
1424         return JIM_ERR;
1425
1426     Jim_SetResult(interp, JimNewViewObj(interp, proj.Hash(hash, argc - 1)));
1427     return JIM_OK;
1428 }
1429
1430 /* Relational operations --------------------------------------------------- */
1431
1432 static int view_cmd_join(Jim_Interp *interp, int argc, Jim_Obj *const *argv)
1433 {
1434     const c4_View *viewPtr = (const c4_View *)Jim_CmdPrivData(interp);
1435     c4_View other, props;
1436     int outer, off;
1437
1438     if (JimGetView(interp, argv[0], &other) != JIM_OK)
1439         return JIM_ERR;
1440
1441     off = 1; outer = 0;
1442     if (Jim_CompareStringImmediate(interp, argv[1], "-outer")) {
1443         off++; outer = 1;
1444     }
1445
1446     if (JimGetProperties(interp, argc - off, argv + off, *viewPtr, &props) != JIM_OK)
1447         return JIM_ERR;
1448
1449     Jim_SetResult(interp, JimNewViewObj(interp, viewPtr->Join(props, other, outer)));
1450     return JIM_OK;
1451 }
1452
1453 static int view_cmd_group(Jim_Interp *interp, int argc, Jim_Obj *const *argv)
1454 {
1455     const c4_View *viewPtr = (const c4_View *)Jim_CmdPrivData(interp);
1456     const c4_Property *subviewPtr;
1457     c4_View props;
1458
1459     if (JimGetPropertyTyped(interp, argv[0], MK_PROPERTY_VIEW, &subviewPtr) != JIM_OK)
1460         return JIM_ERR;
1461
1462     if (JimGetProperties(interp, argc - 1, argv + 1, *viewPtr, &props) != JIM_OK)
1463         return JIM_ERR;
1464
1465     Jim_SetResult(interp, JimNewViewObj(interp, viewPtr->GroupBy(props, *(c4_ViewProp *)subviewPtr)));
1466     return JIM_OK;
1467 }
1468
1469 static int view_cmd_flatten(Jim_Interp *interp, int argc, Jim_Obj *const *argv)
1470 {
1471     const c4_View *viewPtr = (const c4_View *)Jim_CmdPrivData(interp);
1472     const c4_Property *subviewPtr;
1473
1474     if (JimGetProperty(interp, argv[0], *viewPtr, NULL, &subviewPtr) != JIM_OK)
1475         return JIM_ERR;
1476
1477     if (subviewPtr->Type() != MK_PROPERTY_VIEW) {
1478         Jim_SetResultFormatted(interp, "expected a subview property but got %s one",
1479             JimMkTypeName(subviewPtr->Type()));
1480         return JIM_ERR;
1481     }
1482
1483     Jim_SetResult(interp, JimNewViewObj(interp, viewPtr->JoinProp(*(c4_ViewProp *)subviewPtr)));
1484     return JIM_OK;
1485 }
1486
1487 /* View queries ------------------------------------------------------------ */
1488
1489 static int view_cmd_properties(Jim_Interp *interp, int argc, Jim_Obj *const *argv)
1490 {
1491     const c4_View *viewPtr = (const c4_View *) Jim_CmdPrivData(interp);
1492     Jim_SetResult(interp, JimViewPropertiesList(interp, *viewPtr));
1493     return JIM_OK;
1494 }
1495
1496 static int view_cmd_size(Jim_Interp *interp, int argc, Jim_Obj *const *argv)
1497 {
1498     const c4_View *viewPtr = (const c4_View *) Jim_CmdPrivData(interp);
1499     Jim_SetResultInt(interp, viewPtr->GetSize());
1500     return JIM_OK;
1501 }
1502
1503 static int view_cmd_resize(Jim_Interp *interp, int argc, Jim_Obj *const *argv)
1504 {
1505     c4_View *view = (c4_View *) Jim_CmdPrivData(interp);
1506     jim_wide size;
1507
1508     if (Jim_GetWide(interp, argv[0], &size) != JIM_OK)
1509         return JIM_ERR;
1510     if (size < 0 || size > INT_MAX) {
1511         Jim_SetResultFormatted(interp,
1512             "view size \"%#s\" is out of range", argv[0]);
1513         return JIM_ERR;
1514     }
1515
1516     view->SetSize((int)size);
1517     Jim_SetResult(interp, argv[0]);
1518     return JIM_OK;
1519 }
1520
1521 static int view_cmd_type(Jim_Interp *interp, int argc, Jim_Obj *const *argv)
1522 {
1523     const c4_View *viewPtr = (const c4_View *)Jim_CmdPrivData(interp);
1524
1525     if (argc == 1) {
1526         const c4_Property *propPtr;
1527
1528         if (JimGetProperty(interp, argv[0], *viewPtr, NULL, &propPtr) != JIM_OK)
1529             return JIM_ERR;
1530
1531         Jim_SetResultString(interp, JimMkTypeName(propPtr->Type()), -1);
1532     }
1533     else {
1534         Jim_Obj *result;
1535         int i, count;
1536
1537         result = Jim_NewListObj(interp, NULL, 0);
1538         count = viewPtr->NumProperties();
1539
1540         for (i = 0; i < count; i++) {
1541             c4_Property prop = viewPtr->NthProperty(i);
1542             Jim_ListAppendElement(interp, result, JimNewPropertyObj(interp, prop));
1543             Jim_ListAppendElement(interp, result,
1544                 Jim_NewStringObj(interp, JimMkTypeName(prop.Type()), -1));
1545         }
1546
1547         Jim_SetResult(interp, result);
1548     }
1549
1550     return JIM_OK;
1551 }
1552
1553 /* View lifetime ----------------------------------------------------------- */
1554
1555 static int view_cmd_pin(Jim_Interp *interp, int argc, Jim_Obj *const *argv)
1556 {
1557     JimPinView(interp, argv[0]);
1558     Jim_SetResult(interp, argv[0]);
1559     return JIM_OK;
1560 }
1561
1562 static int view_cmd_as(Jim_Interp *interp, int argc, Jim_Obj *const *argv)
1563 {
1564     JimPinView(interp, argv[0]);
1565     Jim_SetVariable(interp, argv[2], argv[0]);
1566     Jim_SetResult(interp, argv[0]);
1567     return JIM_OK;
1568 }
1569
1570 static int view_cmd_destroy(Jim_Interp *interp, int argc, Jim_Obj *const *argv)
1571 {
1572     Jim_DeleteCommand(interp, Jim_String(argv[0]));
1573     return JIM_OK;
1574 }
1575
1576 /* Command table ----------------------------------------------------------- */
1577
1578 static const jim_subcmd_type view_command_table[] = {
1579
1580     /* Unary operations */
1581
1582     {   "copy", "",
1583         view_cmd_copy,
1584         0, 0,
1585         0,
1586         /*"Create a copy of the view with exactly the same data"*/
1587     },
1588     {   "clone", "",
1589         view_cmd_clone,
1590         0, 0,
1591         0,
1592         /*"Create an empty view with the same properties as this one"*/
1593     },
1594     {   "unique", "",
1595         view_cmd_unique,
1596         0, 0,
1597         0,
1598         /*"Derived view without any duplicate rows (read-only, no change notifications)"*/
1599     },
1600     {   "blocked", "",
1601         view_cmd_blocked,
1602         0, 0,
1603         0,
1604         /*"Build a scalable \"blocked\" out of a view with a single subview property called _B"*/
1605     },
1606
1607     /* Binary operations */
1608
1609     #define BINOP(name, descr)  \
1610     {   #name, "otherView",     \
1611         view_cmd_##name,        \
1612         1, 1, 0,                \
1613     }
1614
1615     BINOP(pair, "Pairwise concatenation of two views"),
1616     BINOP(concat, "Concatenation of two views; unlike union, doesn't remove duplicates"),
1617     BINOP(product, "Cartesian product of two views, i.e. every row in view paired with every row in otherView"),
1618
1619     /* Set operations */
1620
1621     #define SETOP(name, descr) BINOP(name, descr "; works only if all the rows are unique")
1622
1623     SETOP(union, "Set union of two views (read-only, no change notifications)"),
1624     SETOP(intersect, "Set intersection of two views"),
1625     SETOP(different, "Symmetric difference of two views"),
1626     SETOP(minus, "Set minus, i.e. all rows from view not in otherView"),
1627
1628     #undef SETOP
1629
1630     #undef BINOP
1631
1632     /* Projections and selections */
1633
1634     {   "project", "prop ?prop ...?",
1635         view_cmd_project,
1636         1, -1,
1637         0,
1638         /*"View projection: only the specified properties, in the specified order"*/
1639     },
1640     {   "without", "prop ?prop ...?",
1641         view_cmd_without,
1642         1, -1,
1643         0,
1644         /*"View projection: remove the specified properties"*/
1645     },
1646     {   "range", "first last ?step?",
1647         view_cmd_range,
1648         2, 3,
1649         0,
1650         /*"Range or slice of the view (read-write, no change notifications)"*/
1651     },
1652
1653     /* Ordering */
1654
1655     {   "sort", "?[prop|-prop] ...?",
1656         view_cmd_sort,
1657         0, -1,
1658         0,
1659         /*"Derived view sorted on the specified properties (in order), or on all properties"*/
1660     },
1661     {   "ordered", "prop ?prop ...?",
1662         view_cmd_ordered,
1663         1, -1,
1664         0,
1665         /*"Consider the underlying view ordered on the specified properties"*/
1666     },
1667     {   "hash", "hashView prop ?prop ...?",
1668         view_cmd_hash,
1669         2, -1,
1670         0,
1671         /*"Mapped view maintaining a hash table on the key consisting of the specified properties"*/
1672     },
1673
1674     /* Relational operations */
1675
1676     {   "join", "view ?-outer? prop ?prop ...?",
1677         view_cmd_join,
1678         2, -1,
1679         0,
1680         /*"Relational join with view on the specified properties"*/
1681     },
1682     {   "group", "subviewName prop ?prop ...?",
1683         view_cmd_group,
1684         1, -1,
1685         0,
1686         /*"Group rows with equal specified properties, move all other properties into subview"*/
1687     },
1688     {   "flatten", "subviewProp",
1689         view_cmd_flatten,
1690         1, 1,
1691         0,
1692         /*"Flatten the specified subview; the inverse of group"*/
1693     },
1694
1695     /* Attributes */
1696
1697     {   "properties", "",
1698         view_cmd_properties,
1699         0, 0,
1700         0,
1701         /*"List the properties in this view"*/
1702     },
1703     {   "size", "",
1704         view_cmd_size,
1705         0, 0,
1706         0,
1707         /*"Return the number of records in the view"*/
1708     },
1709     {   "resize", "newSize",
1710         view_cmd_resize,
1711         1, 1,
1712         0,
1713         /*"Set the number of records in the view"*/
1714     },
1715     {   "type", "?prop?",
1716         view_cmd_type,
1717         0, 1,
1718         0,
1719         /*"Return the type of an existing property, or of all properties"*/
1720     },
1721
1722     /* Lifetime management */
1723
1724     {   "pin", "",
1725         view_cmd_pin,
1726         0, 0,
1727         JIM_MODFLAG_FULLARGV,
1728         /*"Marks the view as persistent"*/
1729     },
1730     {   "as", "varName",
1731         view_cmd_as,
1732         1, 1,
1733         JIM_MODFLAG_FULLARGV,
1734         /*"Marks the view as persistent and assigns it to the given variable"*/
1735     },
1736     {   "destroy", "",
1737         view_cmd_destroy,
1738         0, 0,
1739         JIM_MODFLAG_FULLARGV,
1740         /*"Destroys the view explicitly"*/
1741     },
1742
1743     { 0 }
1744 };
1745
1746 static void JimViewDelProc(Jim_Interp *interp, void *privData)
1747 {
1748     delete (c4_View *)privData;
1749 }
1750
1751 static int JimViewSubCmdProc(Jim_Interp *interp, int argc, Jim_Obj *const *argv)
1752 {
1753     int pipe, result;
1754     Jim_Obj *cmdObj;
1755
1756     pipe = JimPipelineBoundary(argc, argv);
1757
1758     if (pipe < 1) {
1759         Jim_WrongNumArgs(interp, 1, argv, "command ...");
1760         return JIM_ERR;
1761     }
1762
1763     /* Check for a Tcl command first, and try builtins afterwards.
1764      * We have to do it in this order so that Jim_ParseSubCmd isn't too greedy
1765      * about abbreviations, and still it can't now detect ambigous abbrevs
1766      * properly :( Tcl commands cannot be abbreviated at all.
1767      */
1768
1769     cmdObj = Jim_NewStringObj(interp, "mk.view ", -1);
1770     Jim_AppendObj(interp, cmdObj, argv[1]);
1771
1772     /* The command will be cached even though we discard the result */
1773     if (Jim_GetCommand(interp, cmdObj, 0) != NULL) {
1774         /* Shuffle the arguments: $view cmd args... => {mk.view cmd} $view args... */
1775
1776         Jim_Obj **objv = (Jim_Obj **)Jim_Alloc(pipe * sizeof(Jim_Obj *));
1777         objv[0] = cmdObj;
1778         objv[1] = argv[0];
1779         memcpy(objv + 2, argv + 2, (pipe - 2) * sizeof(Jim_Obj *));
1780
1781         result = Jim_EvalObjVector(interp, pipe, objv);
1782
1783         Jim_Free(objv);
1784     } else {
1785         Jim_FreeNewObj(interp, cmdObj);
1786         result = Jim_CallSubCmd(interp, Jim_ParseSubCmd(interp, view_command_table, pipe, argv), pipe, argv);
1787     }
1788
1789     if (result != JIM_OK || pipe == argc)
1790         return result;
1791     else
1792         return Jim_EvalObjPrefix(interp, Jim_GetResult(interp), argc - pipe - 1, argv + pipe + 1);
1793 }
1794
1795 static int JimOneShotViewSubCmdProc(Jim_Interp *interp, int argc, Jim_Obj *const *argv)
1796 {
1797     int result;
1798     Jim_Cmd *cmd;
1799
1800     result = JimViewSubCmdProc(interp, argc, argv);
1801
1802     cmd = Jim_GetCommand(interp, argv[0], 0);
1803     if (cmd && !cmd->isproc && cmd->u.native.cmdProc == JimOneShotViewSubCmdProc)
1804         Jim_DeleteCommand(interp, Jim_String(argv[0]));
1805
1806     return result;
1807 }
1808
1809 static int JimViewFinalizerProc(Jim_Interp *interp, int argc, Jim_Obj *const *argv)
1810 {
1811     /* We won't succeed here if the user renamed the command, and this is right */
1812     Jim_DeleteCommand(interp, Jim_String(argv[1]));
1813     return JIM_OK;
1814 }
1815
1816 static Jim_Obj *JimNewViewObj(Jim_Interp *interp, c4_View view) {
1817     Jim_Obj *tag, *ref;
1818
1819     tag = Jim_NewStringObj(interp, "mk.view", -1);
1820     ref = Jim_NewReference(interp, tag, tag, Jim_NewStringObj(interp, "mk.view.finalizer", -1));
1821     Jim_CreateCommand(interp, Jim_String(ref),
1822         JimOneShotViewSubCmdProc, new c4_View(view), JimViewDelProc);
1823
1824     return ref;
1825 }
1826
1827 static int JimGetView(Jim_Interp *interp, Jim_Obj *obj, c4_View *viewPtr)
1828 {
1829     Jim_Cmd *cmd = Jim_GetCommand(interp, obj, 0);
1830
1831     if (cmd == NULL || cmd->isproc || cmd->u.native.delProc != JimViewDelProc) {
1832         Jim_SetResultFormatted(interp, "invalid view object \"%#s\"", obj);
1833         return JIM_ERR;
1834     }
1835
1836     *viewPtr = *(c4_View *)cmd->u.native.privData;
1837     return JIM_OK;
1838 }
1839
1840 /* Only call this against known view objects. */
1841 static void JimPinView(Jim_Interp *interp, Jim_Obj *obj)
1842 {
1843     Jim_Cmd *cmd = Jim_GetCommand(interp, obj, 0);
1844     /* JimPanic((cmd == NULL, "JimPinView called against non-view"))
1845        JimPanic((cmd->u.native.delProc != JimViewDelProc, "JimPinView called against non-view")) */
1846     cmd->u.native.cmdProc = JimViewSubCmdProc;
1847 }
1848
1849 static Jim_Obj *JimViewPropertiesList(Jim_Interp *interp, c4_View view)
1850 {
1851     int i, count;
1852     Jim_Obj *result;
1853
1854     result = Jim_NewListObj(interp, NULL, 0);
1855     count = view.NumProperties();
1856
1857     for (i = 0; i < count; i++) {
1858         Jim_ListAppendElement(interp, result, Jim_NewStringObj(interp,
1859             view.NthProperty(i).Name(), -1));
1860     }
1861
1862     return result;
1863 }
1864
1865 /* ----------------------------------------------------------------------------
1866  * Storage handle
1867  * ---------------------------------------------------------------------------- */
1868
1869 /* These are also commands, like views, but must be managed explicitly by the
1870  * user. Quite like file handles, actually.
1871  */
1872
1873 typedef struct MkStorage {
1874     unsigned flags;
1875     Jim_Obj *filename;
1876     c4_Storage storage;
1877     c4_Cursor content;
1878 } MkStorage;
1879
1880 #define JIM_MKFLAG_INMEMORY     0x0001
1881 #define JIM_MKFLAG_READONLY     0x0002
1882 #define JIM_MKFLAG_EXTEND       0x0004
1883 #define JIM_MKFLAG_AUTOCOMMIT   0x0008
1884
1885 /* Attributes -------------------------------------------------------------- */
1886
1887 static int storage_cmd_autocommit(Jim_Interp *interp, int argc, Jim_Obj *const *argv)
1888 {
1889     MkStorage *mk = (MkStorage *)Jim_CmdPrivData(interp);
1890
1891     if (argc == 1) {
1892         jim_wide flag;
1893
1894         if (Jim_GetWide(interp, argv[0], &flag) != JIM_OK)
1895             return JIM_ERR;
1896
1897         if (flag)
1898             mk->flags |= JIM_MKFLAG_AUTOCOMMIT;
1899         else
1900             mk->flags &= ~JIM_MKFLAG_AUTOCOMMIT;
1901         mk->storage.AutoCommit(flag);
1902     }
1903
1904     Jim_SetResultBool(interp, (mk->flags & JIM_MKFLAG_AUTOCOMMIT) != 0);
1905     return JIM_OK;
1906 }
1907
1908 static int storage_cmd_readonly(Jim_Interp *interp, int argc, Jim_Obj *const *argv)
1909 {
1910     MkStorage *mk = (MkStorage *)Jim_CmdPrivData(interp);
1911
1912     Jim_SetResultBool(interp, (mk->flags & JIM_MKFLAG_READONLY) != 0);
1913     return JIM_OK;
1914 }
1915
1916 /* Views ------------------------------------------------------------------- */
1917
1918 static int storage_cmd_views(Jim_Interp *interp, int argc, Jim_Obj *const *argv)
1919 {
1920     MkStorage *mk = (MkStorage *)Jim_CmdPrivData(interp);
1921
1922     Jim_SetResult(interp, JimViewPropertiesList(interp, mk->storage));
1923     return JIM_OK;
1924 }
1925
1926 static int storage_cmd_view(Jim_Interp *interp, int argc, Jim_Obj *const *argv)
1927 {
1928     MkStorage *mk = (MkStorage *)Jim_CmdPrivData(interp);
1929     const c4_Property *propPtr;
1930
1931     if (JimGetProperty(interp, argv[0], mk->storage, "view", &propPtr) != JIM_OK)
1932         return JIM_ERR;
1933     Jim_SetResult(interp, JimGetMkValue(interp, mk->content, *propPtr));
1934
1935     if (argc == 1)
1936         return JIM_OK;
1937     else {
1938         if (!Jim_CompareStringImmediate(interp, argv[1], "|")) {
1939             Jim_SetResultFormatted(interp,
1940                 "expected start of a pipeline but got \"%#s\"", argv[1]);
1941             return JIM_ERR;
1942         }
1943         return Jim_EvalObjPrefix(interp, Jim_GetResult(interp), argc - 2, argv + 2);
1944     }
1945 }
1946
1947 static int storage_cmd_structure(Jim_Interp *interp, int argc, Jim_Obj *const *argv)
1948 {
1949     MkStorage *mk = (MkStorage *)Jim_CmdPrivData(interp);
1950
1951     if (argc < 2) { /* Query */
1952         const char *name;
1953
1954         if (argc == 0)
1955             name = NULL;
1956         else {
1957             const c4_Property *propPtr;
1958
1959             if (JimGetProperty(interp, argv[0], mk->storage, "view", &propPtr) != JIM_OK)
1960                 return JIM_ERR;
1961             name = propPtr->Name();
1962         }
1963
1964         Jim_SetResult(interp, JimFromMkDescription(interp,
1965             mk->storage.Description(name), NULL));
1966     }
1967     else { /* Modify */
1968         char *descr;
1969         const char *name;
1970         int len, dlen;
1971
1972         if (JimCheckMkName(interp, argv[0], "view") != JIM_OK)
1973             return JIM_ERR;
1974         name = Jim_GetString(argv[0], &len);
1975
1976         if (JimToMkDescription(interp, argv[1], &descr) != JIM_OK)
1977             return JIM_ERR;
1978         dlen = strlen(descr);
1979
1980         descr = (char *)Jim_Realloc(descr, dlen + len + 2);
1981         memmove(descr + len + 1, descr, dlen);
1982         memcpy(descr, name, len);
1983         descr[len] = '[';
1984         descr[len + 1 + dlen] = ']';
1985         descr[len + 1 + dlen + 1] = '\0';
1986
1987         mk->storage.GetAs(descr);
1988
1989         Jim_Free(descr);
1990     }
1991
1992     return JIM_OK;
1993 }
1994
1995 /* Store operations -------------------------------------------------------- */
1996
1997 static int storage_cmd_commit(Jim_Interp *interp, int argc, Jim_Obj *const *argv)
1998 {
1999     MkStorage *mk = (MkStorage *)Jim_CmdPrivData(interp);
2000
2001     if (mk->flags & JIM_MKFLAG_INMEMORY) {
2002         Jim_SetResultString(interp, "cannot commit an in-memory storage", -1);
2003         return JIM_ERR;
2004     }
2005     else if (mk->flags & JIM_MKFLAG_READONLY) {
2006         Jim_SetResultString(interp, "cannot commit a read-only storage", -1);
2007         return JIM_ERR;
2008     }
2009
2010     if (mk->storage.Commit(0)) {
2011         Jim_SetEmptyResult(interp);
2012         return JIM_OK;
2013     }
2014     else {
2015         Jim_SetResultString(interp, "I/O error during commit", -1);
2016         return JIM_ERR;
2017     }
2018 }
2019
2020 static int storage_cmd_rollback(Jim_Interp *interp, int argc, Jim_Obj *const *argv)
2021 {
2022     MkStorage *mk = (MkStorage *)Jim_CmdPrivData(interp);
2023
2024     if (mk->flags & JIM_MKFLAG_INMEMORY) {
2025         Jim_SetResultString(interp, "cannot rollback an in-memory storage", -1);
2026         return JIM_ERR;
2027     }
2028
2029     if (mk->storage.Rollback(0)) {
2030         Jim_SetEmptyResult(interp);
2031         return JIM_OK;
2032     }
2033     else {
2034         Jim_SetResultString(interp, "I/O error during rollback", -1);
2035         return JIM_ERR;
2036     }
2037 }
2038
2039 static int storage_cmd_close(Jim_Interp *interp, int argc, Jim_Obj *const *argv)
2040 {
2041     return Jim_DeleteCommand(interp, Jim_String(argv[0]));
2042 }
2043
2044 /* Command table ----------------------------------------------------------- */
2045
2046 static const jim_subcmd_type storage_command_table[] = {
2047
2048     /* Options */
2049
2050     {   "autocommit", "?value?",
2051         storage_cmd_autocommit,
2052         0, 1,
2053         0,
2054         /*"Query or modify the auto-commit option of this storage"*/
2055     },
2056     {   "readonly", "",
2057         storage_cmd_readonly,
2058         0, 0,
2059         0,
2060         /*"Returns the read-only status of this storage"*/
2061     },
2062
2063     /* Views */
2064
2065     {   "views", "",
2066         storage_cmd_views,
2067         0, 0,
2068         0,
2069         /*"Returns the list of views stored here"*/
2070     },
2071     {   "view", "viewName",
2072         storage_cmd_view,
2073         1, -1,
2074         0,
2075         /*"Retrieve the view specified by viewName"*/
2076     },
2077     {   "structure", "?viewName? ?description?",
2078         storage_cmd_structure,
2079         0, 2,
2080         0,
2081         /*"Query or modify the structure of this storage"*/
2082     },
2083
2084     /* Store operations */
2085
2086     {   "commit", "",
2087         storage_cmd_commit,
2088         0, 0,
2089         0,
2090         /*"Commit the changes to disk"*/
2091     },
2092     {   "rollback", "",
2093         storage_cmd_rollback,
2094         0, 0,
2095         0,
2096         /*"Revert to the saved state"*/
2097     },
2098     {   "close", "",
2099         storage_cmd_close,
2100         0, 0,
2101         JIM_MODFLAG_FULLARGV,
2102         /*"Close this storage"*/
2103     },
2104
2105     { 0 }
2106 };
2107
2108 static void JimStorageDelProc(Jim_Interp *interp, void *privData)
2109 {
2110     MkStorage *mk = (MkStorage *)privData;
2111
2112     mk->storage.~c4_Storage();
2113     mk->content.~c4_Cursor();
2114     Jim_DecrRefCount(interp, mk->filename);
2115     Jim_Free(mk);
2116 }
2117
2118 static int JimStorageSubCmdProc(Jim_Interp *interp, int argc, Jim_Obj *const *argv)
2119 {
2120     Jim_Obj *cmdObj;
2121
2122     cmdObj = Jim_NewStringObj(interp, "mk.storage ", -1);
2123     Jim_AppendObj(interp, cmdObj, argv[1]);
2124
2125     if (Jim_GetCommand(interp, cmdObj, 0) != NULL) {
2126         int result;
2127
2128         Jim_Obj **objv = (Jim_Obj **)Jim_Alloc(argc * sizeof(Jim_Obj *));
2129         objv[0] = cmdObj;
2130         objv[1] = argv[0];
2131         memcpy(objv + 2, argv + 2, (argc - 2) * sizeof(Jim_Obj *));
2132
2133         result = Jim_EvalObjVector(interp, argc, objv);
2134
2135         Jim_Free(objv);
2136         return result;
2137     } else {
2138         Jim_FreeNewObj(interp, cmdObj);
2139         return Jim_CallSubCmd(interp, Jim_ParseSubCmd(interp,
2140             storage_command_table, argc, argv), argc, argv);
2141     }
2142 }
2143
2144 /* -------------------------------------------------------------------------
2145  * storage ?options? ?filename?
2146  *
2147  * Creates a new metakit storage object, optionally backed by a file.
2148  *
2149  * Options apply only when filename is given; these include:
2150  *
2151  *   -readonly   Open the file in read-only mode
2152  *   -original   Open the file in read-only mode, discarding possible extends
2153  *   -extend     Open the file in extend mode
2154  *   -nocommit   Do not commit the changes when the storage is closed
2155  * ------------------------------------------------------------------------- */
2156
2157 static int JimStorageCommand(Jim_Interp *interp, int argc, Jim_Obj *const *argv)
2158 {
2159     MkStorage *mk;
2160     char buf[MK_CMD_LEN];
2161     int i, mode;
2162
2163     static const char *const options[] = {
2164         "-readonly",
2165         "-original",
2166         "-extend",
2167         "-nocommit",
2168         0
2169     };
2170     enum {
2171         OPT_READONLY,
2172         OPT_ORIGINAL,
2173         OPT_EXTEND,
2174         OPT_NOCOMMIT
2175     };
2176     int option;
2177
2178     mk = (MkStorage *)Jim_Alloc(sizeof(MkStorage));
2179     mk->flags = JIM_MKFLAG_AUTOCOMMIT;
2180     mode = MK_MODE_READWRITE;
2181     for (i = 1; i < argc - 1; i++ ) {
2182         if (Jim_GetEnum(interp, argv[i], options, &option, NULL, JIM_ERRMSG) != JIM_OK) {
2183             Jim_Free(mk);
2184             return JIM_ERR;
2185         }
2186
2187         switch (option) {
2188             case OPT_READONLY:
2189                 if (mode != MK_MODE_READWRITE)
2190                     goto modeconflict;
2191
2192                 mode = MK_MODE_READONLY;
2193                 mk->flags |= JIM_MKFLAG_READONLY;
2194                 break;
2195
2196             case OPT_ORIGINAL:
2197                 if (mode != MK_MODE_READWRITE)
2198                     goto modeconflict;
2199
2200                 mode = MK_MODE_ORIGINAL;
2201                 mk->flags |= JIM_MKFLAG_READONLY;
2202                 break;
2203
2204             case OPT_EXTEND:
2205                 if (mode != MK_MODE_READWRITE)
2206                     goto modeconflict;
2207
2208                 mode = MK_MODE_EXTEND;
2209                 mk->flags |= JIM_MKFLAG_EXTEND;
2210                 break;
2211
2212             case OPT_NOCOMMIT:
2213                 mk->flags &= ~JIM_MKFLAG_AUTOCOMMIT;
2214                 break;
2215         }
2216     }
2217
2218     if (argc > 1) {
2219         new(&mk->storage) c4_Storage(Jim_String(argv[argc-1]), mode);
2220
2221         if (!mk->storage.Strategy().IsValid()) {
2222             mk->storage.~c4_Storage();
2223             Jim_Free(mk);
2224             Jim_SetResultFormatted(interp, "could not open storage \"%#s\"", argv[argc-1]);
2225             return JIM_ERR;
2226         }
2227
2228         mk->filename = argv[argc-1];
2229
2230         if ((mk->flags & JIM_MKFLAG_AUTOCOMMIT) && !(mk->flags & JIM_MKFLAG_READONLY))
2231             mk->storage.AutoCommit(1);
2232     }
2233     else {
2234         mk->flags |= JIM_MKFLAG_INMEMORY;
2235
2236         new(&mk->storage) c4_Storage();
2237         mk->filename = Jim_NewEmptyStringObj(interp);
2238     }
2239     new(&mk->content) c4_Cursor(&mk->storage[0]);
2240     Jim_IncrRefCount(mk->filename);
2241
2242     snprintf(buf, sizeof(buf), "mk.handle%ld", Jim_GetId(interp));
2243     Jim_CreateCommand(interp, buf, JimStorageSubCmdProc, mk, JimStorageDelProc);
2244     Jim_SetResultString(interp, buf, -1);
2245     return JIM_OK;
2246
2247   modeconflict:
2248     Jim_Free(mk);
2249     Jim_SetResultString(interp, "only one of -readonly, -original and -extend may be specified", -1);
2250     return JIM_ERR;
2251 }
2252
2253 /* -------------------------------------------------------------------------
2254  * Initialization code
2255  * ------------------------------------------------------------------------- */
2256
2257 int Jim_mkInit(Jim_Interp *interp)
2258 {
2259     char version[MK_VERSION_SPACE];
2260
2261     snprintf(version, MK_VERSION_SPACE, "%d.%d.%d",
2262         d4_MetakitLibraryVersion / 100,
2263         d4_MetakitLibraryVersion % 100 / 10,
2264         d4_MetakitLibraryVersion % 10);
2265
2266     if (Jim_PackageProvide(interp, "mk", version, JIM_ERRMSG))
2267         return JIM_ERR;
2268
2269     Jim_CreateCommand(interp, "storage", JimStorageCommand, NULL, NULL);
2270     Jim_CreateCommand(interp, "cursor", JimCursorCommand, NULL, NULL);
2271     Jim_CreateCommand(interp, "mk.view.finalizer", JimViewFinalizerProc, NULL, NULL);
2272
2273     return JIM_OK;
2274 }
2275
2276 } /* extern "C" */