summaryrefslogtreecommitdiff
path: root/src/ldblib.js
diff options
context:
space:
mode:
Diffstat (limited to 'src/ldblib.js')
-rw-r--r--src/ldblib.js60
1 files changed, 60 insertions, 0 deletions
diff --git a/src/ldblib.js b/src/ldblib.js
index 39b9574..efab872 100644
--- a/src/ldblib.js
+++ b/src/ldblib.js
@@ -5,9 +5,69 @@ const assert = require('assert');
const lua = require('./lua.js');
const lapi = require('./lapi.js');
const lauxlib = require('./lauxlib.js');
+const ldebug = require('./ldebug.js');
+/*
+** If L1 != L, L1 can be in any state, and therefore there are no
+** guarantees about its stack space; any push in L1 must be
+** checked.
+*/
+const checkstack = function(L, L1, n) {
+ if (L !== L1 && !lapi.lua_checkstack(L1, n))
+ lauxlib.luaL_error(L, "stack overflow");
+};
+
+/*
+** Auxiliary function used by several library functions: check for
+** an optional thread as function's first argument and set 'arg' with
+** 1 if this argument is present (so that functions can skip it to
+** access their other arguments)
+*/
+const getthread = function(L) {
+ if (lapi.lua_isthread(L, 1)) {
+ return {
+ arg: 1,
+ thread: lapi.lua_tothread(L, 1)
+ };
+ } else {
+ return {
+ arg: 0,
+ thread: L
+ }; /* function will operate over current thread */
+ }
+};
+
+const db_getlocal = function(L) {
+ let thread = getthread(L);
+ let L1 = thread.thread;
+ let arg = thread.arg;
+ let ar = new lua.lua_Debug();
+ let nvar = lauxlib.luaL_checkinteger(L, arg + 2); /* local-variable index */
+ if (lapi.lua_isfunction(L, arg + 1)) {
+ lapi.lua_pushvalue(L, arg + 1); /* push function */
+ lapi.lua_pushstring(L, ldebug.lua_getlocal(L, null, nvar)); /* push local name */
+ return 1; /* return only name (there is no value) */
+ } else { /* stack-level argument */
+ let level = lauxlib.luaL_checkinteger(L, arg + 1);
+ if (!ldebug.lua_getstack(L1, level, ar)) /* out of range? */
+ return lauxlib.luaL_argerror(L, arg+1, lapi.to_luastring("level out of range"));
+ checkstack(L, L1, 1);
+ let name = ldebug.lua_getlocal(L1, ar, nvar);
+ if (name) {
+ lapi.lua_xmove(L1, L, 1); /* move local value */
+ lapi.lua_pushstring(L, name.value); /* push name */
+ lapi.lua_rotate(L, -2, 1); /* re-order */
+ return 2;
+ }
+ else {
+ lapi.lua_pushnil(L); /* no name (nor value) */
+ return 1;
+ }
+ }
+};
const dblib = {
+ "getlocal": db_getlocal
};
// Only with Node