lauxlib.c
上传用户:dzyhzl
上传日期:2019-04-29
资源大小:56270k
文件大小:5k
- /*
- ** $Id: lauxlib.c,v 1.43 2000/10/30 13:07:48 roberto Exp $
- ** Auxiliary functions for building Lua libraries
- ** See Copyright Notice in lua.h
- */
- #include <stdarg.h>
- #include <stdio.h>
- #include <string.h>
- /* This file uses only the official API of Lua.
- ** Any function declared here could be written as an application function.
- ** With care, these functions can be used by other libraries.
- */
- #include "../lua.h"
- #include "../lauxlib.h"
- #include "../luadebug.h"
- LUALIB_API int luaL_findstring (const char *name, const char *const list[]) {
- int i;
- for (i=0; list[i]; i++)
- if (strcmp(list[i], name) == 0)
- return i;
- return -1; /* name not found */
- }
- LUALIB_API void luaL_argerror (lua_State *L, int narg, const char *extramsg) {
- lua_Debug ar;
- lua_getstack(L, 0, &ar);
- lua_getinfo(L, "n", &ar);
- if (ar.name == NULL)
- ar.name = "?";
- luaL_verror(L, "bad argument #%d to `%.50s' (%.100s)",
- narg, ar.name, extramsg);
- }
- static void type_error (lua_State *L, int narg, int t) {
- char buff[50];
- sprintf(buff, "%.8s expected, got %.8s", lua_typename(L, t),
- lua_typename(L, lua_type(L, narg)));
- luaL_argerror(L, narg, buff);
- }
- LUALIB_API void luaL_checkstack (lua_State *L, int space, const char *mes) {
- if (space > lua_stackspace(L))
- luaL_verror(L, "stack overflow (%.30s)", mes);
- }
- LUALIB_API void luaL_checktype(lua_State *L, int narg, int t) {
- if (lua_type(L, narg) != t)
- type_error(L, narg, t);
- }
- LUALIB_API void luaL_checkany (lua_State *L, int narg) {
- if (lua_type(L, narg) == LUA_TNONE)
- luaL_argerror(L, narg, "value expected");
- }
- LUALIB_API const char *luaL_check_lstr (lua_State *L, int narg, size_t *len) {
- const char *s = lua_tostring(L, narg);
- if (!s) type_error(L, narg, LUA_TSTRING);
- if (len) *len = lua_strlen(L, narg);
- return s;
- }
- LUALIB_API const char *luaL_opt_lstr (lua_State *L, int narg, const char *def, size_t *len) {
- if (lua_isnull(L, narg)) {
- if (len)
- *len = (def ? strlen(def) : 0);
- return def;
- }
- else return luaL_check_lstr(L, narg, len);
- }
- LUALIB_API double luaL_check_number (lua_State *L, int narg) {
- double d = lua_tonumber(L, narg);
- if (d == 0 && !lua_isnumber(L, narg)) /* avoid extra test when d is not 0 */
- type_error(L, narg, LUA_TNUMBER);
- return d;
- }
- LUALIB_API double luaL_opt_number (lua_State *L, int narg, double def) {
- if (lua_isnull(L, narg)) return def;
- else return luaL_check_number(L, narg);
- }
- LUALIB_API void luaL_openlib (lua_State *L, const struct luaL_reg *l, int n) {
- int i;
- for (i=0; i<n; i++)
- lua_register(L, l[i].name, l[i].func);
- }
- LUALIB_API void luaL_verror (lua_State *L, const char *fmt, ...) {
- char buff[500];
- va_list argp;
- va_start(argp, fmt);
- vsprintf(buff, fmt, argp);
- va_end(argp);
- lua_error(L, buff);
- }
- /*
- ** {======================================================
- ** Generic Buffer manipulation
- ** =======================================================
- */
- #define buffempty(B) ((B)->p == (B)->buffer)
- #define bufflen(B) ((B)->p - (B)->buffer)
- #define bufffree(B) ((size_t)(LUAL_BUFFERSIZE - bufflen(B)))
- #define LIMIT (LUA_MINSTACK/2)
- static int emptybuffer (luaL_Buffer *B) {
- size_t l = bufflen(B);
- if (l == 0) return 0; /* put nothing on stack */
- else {
- lua_pushlstring(B->L, B->buffer, l);
- B->p = B->buffer;
- B->level++;
- return 1;
- }
- }
- static void adjuststack (luaL_Buffer *B) {
- if (B->level > 1) {
- lua_State *L = B->L;
- int toget = 1; /* number of levels to concat */
- size_t toplen = lua_strlen(L, -1);
- do {
- size_t l = lua_strlen(L, -(toget+1));
- if (B->level - toget + 1 >= LIMIT || toplen > l) {
- toplen += l;
- toget++;
- }
- else break;
- } while (toget < B->level);
- if (toget >= 2) {
- lua_concat(L, toget);
- B->level = B->level - toget + 1;
- }
- }
- }
- LUALIB_API char *luaL_prepbuffer (luaL_Buffer *B) {
- if (emptybuffer(B))
- adjuststack(B);
- return B->buffer;
- }
- LUALIB_API void luaL_addlstring (luaL_Buffer *B, const char *s, size_t l) {
- while (l--)
- luaL_putchar(B, *s++);
- }
- LUALIB_API void luaL_addstring (luaL_Buffer *B, const char *s) {
- luaL_addlstring(B, s, strlen(s));
- }
- LUALIB_API void luaL_pushresult (luaL_Buffer *B) {
- emptybuffer(B);
- if (B->level == 0)
- lua_pushlstring(B->L, NULL, 0);
- else if (B->level > 1)
- lua_concat(B->L, B->level);
- B->level = 1;
- }
- LUALIB_API void luaL_addvalue (luaL_Buffer *B) {
- lua_State *L = B->L;
- size_t vl = lua_strlen(L, -1);
- if (vl <= bufffree(B)) { /* fit into buffer? */
- memcpy(B->p, lua_tostring(L, -1), vl); /* put it there */
- B->p += vl;
- lua_pop(L, 1); /* remove from stack */
- }
- else {
- if (emptybuffer(B))
- lua_insert(L, -2); /* put buffer before new value */
- B->level++; /* add new value into B stack */
- adjuststack(B);
- }
- }
- LUALIB_API void luaL_buffinit (lua_State *L, luaL_Buffer *B) {
- B->L = L;
- B->p = B->buffer;
- B->level = 0;
- }
- /* }====================================================== */