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-rw-r--r--src/lbaselib.js58
1 files changed, 58 insertions, 0 deletions
diff --git a/src/lbaselib.js b/src/lbaselib.js
index 77638d0..a7666b5 100644
--- a/src/lbaselib.js
+++ b/src/lbaselib.js
@@ -251,6 +251,64 @@ const luaB_xpcall = function(L) {
return finishpcall(L, status, 2);
};
+const load_aux = function(L, status, envidx) {
+ if (status === TS.LUA_OK) {
+ if (envidx !== 0) { /* 'env' parameter? */
+ lapi.lua_pushvalue(L, envidx); /* environment for loaded function */
+ if (!lapi.lua_setupvalue(L, -2, 1)) /* set it as 1st upvalue */
+ lapi.lua_pop(L, 1); /* remove 'env' if not used by previous call */
+ }
+ return 1;
+ } else { /* error (message is on top of the stack) */
+ lapi.lua_pushnil(L);
+ lapi.lua_insert(L, -2); /* put before error message */
+ return 2; /* return nil plus error message */
+ }
+};
+
+/*
+** reserved slot, above all arguments, to hold a copy of the returned
+** string to avoid it being collected while parsed. 'load' has four
+** optional arguments (chunk, source name, mode, and environment).
+*/
+const RESERVEDSLOT = 5;
+
+/*
+** Reader for generic 'load' function: 'lua_load' uses the
+** stack for internal stuff, so the reader cannot change the
+** stack top. Instead, it keeps its resulting string in a
+** reserved slot inside the stack.
+*/
+const generic_reader = function(L, ud) {
+ lauxlib.luaL_checkstack(L, 2, "too many nested functions");
+ lapi.lua_pushvalue(L, 1); /* get function */
+ lapi.lua_call(L, 0, 1); /* call it */
+ if (lapi.lua_isnil(L, -1)) {
+ lapi.lua_pop(L, 1); /* pop result */
+ return null;
+ } else if (!lapi.lua_isstring(L, -1))
+ lauxlib.luaL_error(L, "reader function must return a string");
+ lapi.lua_replace(L, RESERVEDSLOT); /* save string in reserved slot */
+ return lapi.lua_tostring(L, RESERVEDSLOT);
+};
+
+const luaB_load = function(L) {
+ let s = lapi.lua_tostring(L, 1);
+ let mode = lauxlib.luaL_optstring(L, 3, "bt");
+ let env = !lapi.lua_isnone(L, 4) ? 4 : 0; /* 'env' index or 0 if no 'env' */
+ let status;
+ if (s !== null) { /* loading a string? */
+ let chunkname = lauxlib.luaL_optstring(L, 2, s);
+ status = lauxlib.luaL_loadbufferx(L, s, chunkname, mode);
+ } else { /* loading from a reader function */
+ let chunkname = lauxlib.luaL_optstring(L, 2, "=(load)");
+ lauxlib.luaL_checktype(L, 1, CT.LUA_TFUNCTION);
+ lapi.lua_settop(L, RESERVEDSLOT); /* create reserved slot */
+ status = lapi.lua_load(L, generic_reader, null, chunkname, mode);
+ }
+ return load_aux(L, status, env);
+};
+
const base_funcs = {
"collectgarbage": function () {},
"assert": luaB_assert,