1.1 --- a/seqlualib.c	Fri Aug 22 12:27:25 2014 +0200
     1.2 +++ b/seqlualib.c	Sat Aug 23 23:13:17 2014 +0200
     1.3 @@ -2,25 +2,37 @@
     1.4  #include <lauxlib.h>
     1.5  #include "seqlualib.h"
     1.6  
     1.7 -#define SEQLUA_ITERTYPE_FUNC 1
     1.8 -#define SEQLUA_ITERTYPE_META 2
     1.9 -#define SEQLUA_ITERTYPE_RAW  3
    1.10 +#define SEQLUA_ITERTYPE_IPAIRS 1
    1.11 +#define SEQLUA_ITERTYPE_CALL   2
    1.12 +#define SEQLUA_ITERTYPE_INDEX  3
    1.13 +#define SEQLUA_ITERTYPE_RAW    4
    1.14  
    1.15  void seqlua_iterinit(lua_State *L, seqlua_Iterator *iter, int idx) {
    1.16 -  luaL_checkany(L, idx);  // provides better error message
    1.17 +  if (luaL_getmetafield(L, idx, "__ipairs")) {
    1.18 +    lua_pushvalue(L, idx);
    1.19 +    lua_call(L, 1, 3);
    1.20 +    iter->itertype = SEQLUA_ITERTYPE_IPAIRS;
    1.21 +  } else {
    1.22 +    if (lua_type(L, idx) == LUA_TFUNCTION) {
    1.23 +      iter->itertype = SEQLUA_ITERTYPE_CALL;
    1.24 +    } else if (
    1.25 +      luaL_getmetafield(L, idx, "__index") ||
    1.26 +      luaL_getmetafield(L, idx, "__len")
    1.27 +    ) {
    1.28 +      lua_pop(L, 1);
    1.29 +      iter->itertype = SEQLUA_ITERTYPE_INDEX;
    1.30 +      iter->len = luaL_len(L, idx);
    1.31 +    } else {
    1.32 +      luaL_checktype(L, idx, LUA_TTABLE);
    1.33 +      iter->itertype = SEQLUA_ITERTYPE_RAW;
    1.34 +    }
    1.35 +    // always occupy 3 stack indicies
    1.36 +    lua_pushnil(L);
    1.37 +    lua_pushnil(L);
    1.38 +    lua_pushnil(L);
    1.39 +    iter->idx = idx;
    1.40 +  }
    1.41    iter->L = L;
    1.42 -  iter->idx = idx;
    1.43 -  if (
    1.44 -    lua_type(L, idx) == LUA_TFUNCTION ||
    1.45 -    (luaL_getmetafield(L, idx, "__call") && (lua_pop(L, 1), 1))
    1.46 -  ) {
    1.47 -    iter->itertype = SEQLUA_ITERTYPE_FUNC;
    1.48 -  } else if (luaL_getmetafield(L, idx, "__index") && (lua_pop(L, 1), 1)) {
    1.49 -    iter->itertype = SEQLUA_ITERTYPE_META;
    1.50 -  } else {
    1.51 -    luaL_checktype(L, idx, LUA_TTABLE);
    1.52 -    iter->itertype = SEQLUA_ITERTYPE_RAW;
    1.53 -  }
    1.54    iter->i = 0;
    1.55  }
    1.56  
    1.57 @@ -28,20 +40,35 @@
    1.58    lua_State *L = iter->L;
    1.59    lua_Integer i = ++iter->i;
    1.60    switch (iter->itertype) {
    1.61 -  case SEQLUA_ITERTYPE_FUNC:
    1.62 +  case SEQLUA_ITERTYPE_IPAIRS:
    1.63 +    lua_pushvalue(L, -3);
    1.64 +    lua_pushvalue(L, -3);
    1.65 +    lua_pushvalue(L, -3);
    1.66 +    lua_call(L, 2, 2);
    1.67 +    if (lua_isnil(L, -2)) {
    1.68 +      lua_pop(L, 5);
    1.69 +      return 0;
    1.70 +    }
    1.71 +    lua_remove(L, -3);
    1.72 +    return 1;
    1.73 +  case SEQLUA_ITERTYPE_CALL:
    1.74      lua_pushvalue(L, iter->idx);
    1.75      lua_call(L, 0, 1);
    1.76      break;
    1.77 -  case SEQLUA_ITERTYPE_META:
    1.78 +  case SEQLUA_ITERTYPE_INDEX:
    1.79 +    if (i > iter->len) {
    1.80 +      lua_pop(L, 3);
    1.81 +      return 0;
    1.82 +    }
    1.83      lua_pushinteger(L, i);
    1.84      lua_gettable(L, iter->idx);
    1.85 -    break;
    1.86 +    return 1;
    1.87    case SEQLUA_ITERTYPE_RAW:
    1.88      lua_rawgeti(L, iter->idx, i);
    1.89      break;
    1.90    }
    1.91    if (lua_isnil(L, -1)) {
    1.92 -    lua_pop(L, 1);
    1.93 +    lua_pop(L, 4);
    1.94      return 0;
    1.95    }
    1.96    return 1;