lua buffer test

buffertest.c

#define LUA_LIB

#include <lua.h>
#include <lauxlib.h>
#include <string.h>

static void
dump_stack(lua_State *L, const char * name) {
    int top = lua_gettop(L);
    for (int i=1; i<=top; i++) {
        int tp = lua_type(L, i);
        fprintf(stderr, "%s i:%d tp:%s ", name, i, lua_typename(L, tp));
        switch (tp) {
            case LUA_TSTRING:
                fprintf(stderr, "%s\n", lua_tostring(L, i));
                break;
            case LUA_TNIL:
                fprintf(stderr, "nil\n");
                break;
            case LUA_TNUMBER:
                {
                    if (lua_isinteger(L, i)) {
                        fprintf(stderr, "%lld\n", lua_tointeger(L, i));
                    } else {
                        fprintf(stderr, "%f\n", lua_tonumber(L, i));
                    }
                    break;
                }
            case LUA_TBOOLEAN:
                fprintf(stderr, "%s\n", (lua_toboolean(L, i) ? "true" : "false"));
                break;
            default:
                fprintf(stderr, "%p\n", lua_topointer(L, i));
                break;
        }
    }
}

static int
test(lua_State *L) {
    luaL_Buffer b;
    luaL_buffinit(L, &b);
    dump_stack(L, "init");

    int sz = lua_rawlen(L, 1);
    for (size_t i = 1; i <= sz; i++) {
        lua_rawgeti(L, 1, i);
        dump_stack(L, "before");
        printf("push:%s\n", lua_tostring(L, -1));
        luaL_addstring(&b, lua_tostring(L, -1));
        lua_pop(L, 1);
        //luaL_addvalue(&b);
        dump_stack(L, "after");
    }

    luaL_pushresult(&b);
    return 1;
}

LUAMOD_API int
luaopen_buffertest_c(lua_State * L) {
    luaL_checkversion(L);
    luaL_Reg l[] = {
        { "test", test },
        { NULL, NULL },
    };
    luaL_newlib(L, l);
    return 1;
}

testb.lua

local buffertest = require "buffertest.c"

local a = {}
for i=1,100 do
    a[i] = string.rep("x", i)
end

local ret = buffertest.test(a)
print("ok", ret)