jbe@0: #include <lua.h>
jbe@0: #include <lauxlib.h>
jbe@0: #include "seqlualib.h"
jbe@0: 
jbe@15: #define SEQLUA_ITERTYPE_FUNC 1
jbe@15: #define SEQLUA_ITERTYPE_META 2
jbe@15: #define SEQLUA_ITERTYPE_RAW  3
jbe@0: 
jbe@0: void seqlua_iterinit(lua_State *L, seqlua_Iterator *iter, int idx) {
jbe@0:   luaL_checkany(L, idx);  // provides better error message
jbe@0:   iter->L = L;
jbe@15:   iter->idx = idx;
jbe@15:   if (lua_type(L, idx) == LUA_TFUNCTION) {
jbe@0:     iter->itertype = SEQLUA_ITERTYPE_FUNC;
jbe@15:   } else if (luaL_getmetafield(L, idx, "__call")) {
jbe@15:     lua_pop(L, 1);
jbe@15:     iter->itertype = SEQLUA_ITERTYPE_FUNC;
jbe@15:   } else if (luaL_getmetafield(L, idx, "__index")) {
jbe@15:     lua_pop(L, 1);
jbe@15:     iter->itertype = SEQLUA_ITERTYPE_META;
jbe@0:   } else {
jbe@15:     luaL_checktype(L, idx, LUA_TTABLE);
jbe@15:     iter->itertype = SEQLUA_ITERTYPE_RAW;
jbe@0:   }
jbe@0:   iter->i = 0;
jbe@0: }
jbe@0: 
jbe@0: int seqlua_iternext(seqlua_Iterator *iter) {
jbe@0:   lua_State *L = iter->L;
jbe@0:   lua_Integer i = ++iter->i;
jbe@0:   switch (iter->itertype) {
jbe@0:   case SEQLUA_ITERTYPE_FUNC:
jbe@8:     lua_pushvalue(L, iter->idx);
jbe@0:     lua_call(L, 0, 1);
jbe@0:     break;
jbe@0:   case SEQLUA_ITERTYPE_META:
jbe@0:     lua_pushinteger(L, i);
jbe@8:     lua_gettable(L, iter->idx);
jbe@0:     break;
jbe@0:   case SEQLUA_ITERTYPE_RAW:
jbe@8:     lua_rawgeti(L, iter->idx, i);
jbe@8:     break;
jbe@0:   }
jbe@0:   if (lua_isnil(L, -1)) {
jbe@15:     lua_pop(L, 1);
jbe@0:     return 0;
jbe@0:   }
jbe@0:   return 1;
jbe@0: }
jbe@0: 
jbe@0: static int seqlua_iterclosureaux_raw(lua_State *L) {
jbe@0:   lua_Integer i = lua_tointeger(L, lua_upvalueindex(2)) + 1;
jbe@0:   lua_rawgeti(L, lua_upvalueindex(1), i);
jbe@0:   if (lua_isnil(L, -1)) return 1;
jbe@0:   lua_pushinteger(L, i);
jbe@0:   lua_replace(L, lua_upvalueindex(2));
jbe@0:   return 1;
jbe@0: }
jbe@0: 
jbe@0: static int seqlua_iterclosureaux_meta(lua_State *L) {
jbe@0:   lua_Integer i = lua_tointeger(L, lua_upvalueindex(2)) + 1;
jbe@0:   lua_pushinteger(L, i);
jbe@0:   lua_gettable(L, lua_upvalueindex(1));
jbe@0:   if (lua_isnil(L, -1)) return 1;
jbe@0:   lua_pushinteger(L, i);
jbe@0:   lua_replace(L, lua_upvalueindex(2));
jbe@0:   return 1;
jbe@0: }
jbe@0: 
jbe@0: void seqlua_iterclosure(lua_State *L, int idx) {
jbe@8:   luaL_checkany(L, idx);  // provides better error message
jbe@0:   if (lua_type(L, idx) == LUA_TFUNCTION) {
jbe@0:     // do nothing
jbe@0:   } else if (luaL_getmetafield(L, idx, "__call")) {
jbe@15:     lua_pop(L, 1);
jbe@0:   } else if (luaL_getmetafield(L, idx, "__index")) {
jbe@0:     lua_pop(L, 1);
jbe@0:     lua_pushvalue(L, idx);
jbe@0:     lua_pushinteger(L, 0);
jbe@17:     lua_pushcclosure(L, seqlua_iterclosureaux_meta, 2);
jbe@0:     lua_replace(L, idx);
jbe@0:   } else {
jbe@0:     luaL_checktype(L, idx, LUA_TTABLE);
jbe@0:     lua_pushvalue(L, idx);
jbe@0:     lua_pushinteger(L, 0);
jbe@17:     lua_pushcclosure(L, seqlua_iterclosureaux_raw, 2);
jbe@0:     lua_replace(L, idx);
jbe@0:   }
jbe@0: }
jbe@0: