lang_ext/lua/bc_read_stream.c

   1 /*********************************************************************
   2
   3   Gazelle: a system for building fast, reusable grammars
   4
   5   bc_read_stream.c
   6
   7   These are Lua wrappers for bc_read_stream.
   8
   9   Copyright (c) 2007 Joshua Haberman.  See LICENSE for details.
  10
  11 *********************************************************************/
  12
  13 #include "bc_read_stream_lua.h"
  14
  15 #include "lua.h"
  16 #include "lualib.h"
  17 #include "lauxlib.h"
  18
  19 static int bc_read_stream_lua_open(lua_State *L)
  20 {
  21   const char *filename = luaL_checkstring(L, 1);
  22   struct bc_read_stream_lua *s = lua_newuserdata(L, sizeof(*s));
  23   luaL_getmetatable(L, "bc_read_stream");
  24   lua_setmetatable(L, -2);
  25   s->s = bc_rs_open_file(filename);
  26   if(!s->s)
  27     return luaL_error(L, "Couldn't open bitcode file %s", filename);
  28   else
  29     return 1;
  30 }
  31
  32 static int bc_read_stream_lua_next_record(lua_State *L)
  33 {
  34   struct bc_read_stream_lua *s = luaL_checkudata(L, 1, "bc_read_stream");
  35   struct record_info ri = bc_rs_next_data_record(s->s);
  36
  37   if(ri.record_type == Eof)
  38   {
  39     lua_pushnil(L);
  40     return 1;
  41   }
  42   else if(ri.record_type == DataRecord)
  43   {
  44     lua_pushstring(L, "data");
  45     lua_pushnumber(L, ri.id);
  46     for(int i = 0; i < bc_rs_get_record_size(s->s); i++)
  47       lua_pushnumber(L, bc_rs_read_64(s->s, i));
  48     return bc_rs_get_record_size(s->s) + 2;
  49   }
  50   else if(ri.record_type == StartBlock)
  51   {
  52     lua_pushstring(L, "startblock");
  53     lua_pushnumber(L, ri.id);
  54     return 2;
  55   }
  56   else if(ri.record_type == EndBlock)
  57   {
  58     lua_pushstring(L, "endblock");
  59     return 1;
  60   }
  61
  62   /* compiler too stupid to realize that this is unreachable */
  63   return 0;
  64 }
  65
  66 static const luaL_reg global_functions[] =
  67 {
  68   {"open", bc_read_stream_lua_open},
  69   {NULL, NULL}
  70 };
  71
  72 static const luaL_reg read_stream_methods[] =
  73 {
  74   {"next_record", bc_read_stream_lua_next_record},
  75   {NULL, NULL}
  76 };
  77
  78 int luaopen_bc_read_stream(lua_State *L)
  79 {
  80   luaL_newmetatable(L, "bc_read_stream");
  81
  82   /* metatable.__index = metatable */
  83   lua_pushvalue(L, -1); /* duplicates the metatable */
  84   lua_setfield(L, -2, "__index");
  85
  86   luaL_register(L, NULL, read_stream_methods);
  87   luaL_register(L, "bc_read_stream", global_functions);
  88   return 1;
  89 }
  90
  91 /* Local Variables:
  92  * c-set-style: "bsd"
  93  * c-basic-offset: 2
  94  * indent-tabs-mode: nil
  95  * End:
  96  * vim: et sts=2 sw=2
  97  */