path: root/doc/pydoc/ranger.fsobject.fsobject.html

/*
** $Id: lua.c,v 1.160.1.2 2007/12/28 15:32:23 roberto Exp $
** Lua stand-alone interpreter
** See Copyright Notice in lua.h
*/


#include <assert.h>
#include <ctype.h>
#include <fcntl.h>
#include <locale.h>
#include <ncurses.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <unistd.h>

#define lua_c

#include "lua.h"
//? #include "lstate.h"
#include "teliva.h"

#include "lauxlib.h"
#include "lualib.h"


#define BG(i) (COLOR_PAIR((i)+8))
#define FG(i) (COLOR_PAIR(i))


static lua_State *globalL = NULL;

static const char *progname = LUA_PROGNAME;



static void lstop (lua_State *L, lua_Debug *ar) {
  (void)ar;  /* unused arg. */
  lua_sethook(L, NULL, 0, 0);
  luaL_error(L, "interrupted!");
}


static void laction (int i) {
  signal(i, SIG_DFL); /* if another SIGINT happens before lstop,
                              terminate process (default action) */
  lua_sethook(globalL, lstop, LUA_MASKCALL | LUA_MASKRET | LUA_MASKCOUNT, 1);
}


static void print_usage (void) {
  printw(
  "usage: %s [options] [script [args]].\n"
  "Available options are:\n"
  "  -e stat  execute string " LUA_QL("stat") "\n"
  "  -l name  require library " LUA_QL("name") "\n"
  "  -i       enter interactive mode after executing " LUA_QL("script") "\n"
  "  -v       show version information\n"
  "  --       stop handling options\n"
  ,
  progname);
  refresh();
}


static void l_message (const char *pname, const char *msg) {
  if (!stdscr || isendwin()) {
    printf("%s: %s\n", pname, msg);
    exit(1);
  }
  if (pname) mvprintw(LINES-2, 0, "%s: ", pname);
  printw(msg);
  mvprintw(LINES-1, 0, "sorry, you'll need to edit the image directly. press any key to exit.");
  refresh();
  getch();
}


static int report (lua_State *L, int status) {
  if (status && !lua_isnil(L, -1)) {
    const char *msg = lua_tostring(L, -1);
    if (msg == NULL) msg = "(error object is not a string)";
    l_message(progname, msg);
    lua_pop(L, 1);
  }
  return status;
}


static int traceback (lua_State *L) {
  if (!lua_isstring(L, 1))  /* 'message' not a string? */
    return 1;  /* keep it intact */
  lua_getfield(L, LUA_GLOBALSINDEX, "debug");
  if (!lua_istable(L, -1)) {
    lua_pop(L, 1);
    return 1;
  }
  lua_getfield(L, -1, "traceback");
  if (!lua_isfunction(L, -1)) {
    lua_pop(L, 2);
    return 1;
  }
  lua_pushvalue(L, 1);  /* pass error message */
  lua_pushinteger(L, 2);  /* skip this function and traceback */
  lua_call(L, 2, 1);  /* call debug.traceback */
  return 1;
}


static int docall (lua_State *L, int narg, int clear) {
  int status;
  int base = lua_gettop(L) - narg;  /* function index */
  lua_pushcfunction(L, traceback);  /* push traceback function */
  lua_insert(L, base);  /* put it under chunk and args */
  signal(SIGINT, laction);
  status = lua_pcall(L, narg, (clear ? 0 : LUA_MULTRET), base);
  signal(SIGINT, SIG_DFL);
  lua_remove(L, base);  /* remove traceback function */
  /* force a complete garbage collection in case of errors */
  if (status != 0) lua_gc(L, LUA_GCCOLLECT, 0);
  return status;
}


static void print_version (void) {
  l_message(NULL, LUA_RELEASE "  " LUA_COPYRIGHT);
}


/* pushes commandline args to the stack, then an array of all commandline args */
static int getargs (lua_State *L, char **argv, int n) {
  int narg;
  int i;
  int argc = 0;
  while (argv[argc]) argc++;  /* count total number of arguments */
  narg = argc - (n + 1);  /* number of arguments to the script */
  luaL_checkstack(L, narg + 3, "too many arguments to script");
  for (i=n+1; i < argc; i++)
    lua_pushstring(L, argv[i]);
  lua_createtable(L, narg, n + 1);
  for (i=0; i < argc; i++) {
    lua_pushstring(L, argv[i]);
    lua_rawseti(L, -2, i - n);
  }
  return narg;
}


static int dofile (lua_State *L, const char *name) {
  int status = luaL_loadfile(L, name) || docall(L, 0, 1);
  return report(L, status);
}


static int dostring (lua_State *L, const char *s, const char *name) {
  int status = luaL_loadbuffer(L, s, strlen(s), name) || docall(L, 0, 1);
  return report(L, status);
}


static int dolibrary (lua_State *L, const char *name) {
  lua_getglobal(L, "require");
  lua_pushstring(L, name);
  return report(L, docall(L, 1, 1));
}


static const char *get_prompt (lua_State *L, int firstline) {
  const char *p;
  lua_getfield(L, LUA_GLOBALSINDEX, firstline ? "_PROMPT" : "_PROMPT2");
  p = lua_tostring(L, -1);
  if (p == NULL) p = (firstline ? LUA_PROMPT : LUA_PROMPT2);
  lua_pop(L, 1);  /* remove global */
  return p;
}


static int incomplete (lua_State *L, int status) {
  if (status == LUA_ERRSYNTAX) {
    size_t lmsg;
    const char *msg = lua_tolstring(L, -1, &lmsg);
    const char *tp = msg + lmsg - (sizeof(LUA_QL("<eof>")) - 1);
    if (strstr(msg, LUA_QL("<eof>")) == tp) {
      lua_pop(L, 1);
      return 1;
    }
  }
  return 0;  /* else... */
}


static int pushline (lua_State *L, int firstline) {
  char buffer[LUA_MAXINPUT];
  char *b = buffer;
  size_t l;
  const char *prmt = get_prompt(L, firstline);
  addstr(prmt);
  refresh();
  getnstr(b, LUA_MAXINPUT);
  l = strlen(b);
  if (l > 0 && b[l-1] == '\n')  /* line ends with newline? */
    b[l-1] = '\0';  /* remove it */
  if (firstline && b[0] == '=')  /* first line starts with `=' ? */
    lua_pushfstring(L, "return %s", b+1);  /* change it to `return' */
  else
    lua_pushstring(L, b);
  return 1;
}


static int loadline (lua_State *L) {
  int status;
  lua_settop(L, 0);
  if (!pushline(L, 1))
    return -1;  /* no input */
  for (;;) {  /* repeat until gets a complete line */
    status = luaL_loadbuffer(L, lua_tostring(L, 1), lua_strlen(L, 1), "=keyboard");
    if (!incomplete(L, status)) break;  /* cannot try to add lines? */
    if (!pushline(L, 0))  /* no more input? */
      return -1;
    lua_pushliteral(L, "\n");  /* add a new line... */
    lua_insert(L, -2);  /* ...between the two lines */
    lua_concat(L, 3);  /* join them */
  }
  lua_remove(L, 1);  /* remove line */
  return status;
}


static void dotty (lua_State *L) {
  int status;
  const char *oldprogname = progname;
  progname = NULL;
  while ((status = loadline(L)) != -1) {
    if (status == 0) status = docall(L, 0, 0);
    report(L, status);
    if (status == 0 && lua_gettop(L) > 0) {  /* any result to print? */
      lua_getglobal(L, "print");
      lua_insert(L, 1);
      if (lua_pcall(L, lua_gettop(L)-1, 0, 0) != 0)
        l_message(progname, lua_pushfstring(L,
                               "error calling " LUA_QL("print") " (%s)",
                               lua_tostring(L, -1)));
    }
  }
  lua_settop(L, 0);  /* clear stack */
  refresh();
  progname = oldprogname;
}


void stack_dump (lua_State *L) {
  int i;
  int top = lua_gettop(L);
  int y = 1;
  for (i = 1; i <= top; i++) {  /* repeat for each level */
    int t = lua_type(L, i);
    switch (t) {

      case LUA_TSTRING:  /* strings */
        mvprintw(y, 30, "`%s'", lua_tostring(L, i));
        break;

      case LUA_TBOOLEAN:  /* booleans */
        mvprintw(y, 30, lua_toboolean(L, i) ? "true" : "false");
        break;

      case LUA_TNUMBER:  /* numbers */
        mvprintw(y, 30, "%g", lua_tonumber(L, i));
        break;

      default:  /* other values */
        mvprintw(y, 30, "%s", lua_typename(L, t));
        break;

    }
    y++;
    mvprintw(y, 30, "  ");  /* put a separator */
    y++;
  }
  mvprintw(y, 30, "\n");  /* end the listing */
  y++;
}


static int binding_exists (lua_State *L, const char *name) {
  int result = 0;
  lua_getglobal(L, name);
  result = !lua_isnil(L, -1);
  lua_pop(L, 1);
  return result;
}


static const char *special_history_keys[] = {
  "__teliva_timestamp",
  "__teliva_undo",
  "__teliva_note",
  NULL,
};

int is_special_history_key(const char *key) {
  for (const char **curr = special_history_keys; *curr != NULL; ++curr) {
    if (strcmp(*curr, key) == 0)
      return 1;
  }
  return 0;
}


/* when found, return 1 and leave string on top of stack
 * when not found, return 0
 * caller is responsible for cleaning up the stack. */
static int look_up_definition (lua_State *L, const char *name) {
  lua_getglobal(L, "teliva_program");
  int history_array = lua_gettop(L);
  /* iterate over mutations in teliva_program history in reverse order */
  int history_array_size = luaL_getn(L, history_array);
  for (int i = history_array_size; i > 0; --i) {
    lua_rawgeti(L, history_array, i);
    int table = lua_gettop(L);
    /* iterate over bindings */
    /* really we expect only one */
    for (lua_pushnil(L); lua_next(L, table) != 0; lua_pop(L, 1)) {
      const char* key = lua_tostring(L, -2);
      if (strcmp(key, "__teliva_undo") == 0) {
        int next_i = lua_tointeger(L, -1);
        assert(next_i < i);
        i = next_i + 1;  /* account for decrement */
        lua_pop(L, 1);
        break;
      }
      if (is_special_history_key(key)) continue;
      if (strcmp(key, name) == 0)
        return 1;
    }
    lua_pop(L, 1);
  }
  lua_pop(L, 1);
  return 0;
}


int load_definitions(lua_State *L) {
  int status;
  lua_getglobal(L, "teliva_program");
  int history_array = lua_gettop(L);
  /* iterate over mutations in teliva_program history in reverse order */
  int history_array_size = luaL_getn(L, history_array);
  for (int i = history_array_size; i > 0; --i) {
    lua_rawgeti(L, history_array, i);
    int table = lua_gettop(L);
    /* iterate over bindings */
    /* really we expect only one */
    for (lua_pushnil(L); lua_next(L, table) != 0; lua_pop(L, 1)) {
      const char* key = lua_tostring(L, -2);
      if (strcmp(key, "__teliva_undo") == 0) {
        int next_i = lua_tointeger(L, -1);
        assert(next_i < i);
        i = next_i + 1;  /* account for decrement */
        lua_pop(L, 1);
        break;
      }
      if (is_special_history_key(key<