Which to use is a matter of preference and circumstance: as the # length operator was introduced in version 5.1, t[#t+1] = i will not work in Lua 5.0, whereas table.insert has been present since 5.0 and will work in both. On the other hand, t[#t+1] = i uses exclusively language-level operators, wheras table.insert involves … Read more
In Lua 5.2 or earlier, both tostring(10) and tostring(10.0) result as the string “10”. In Lua 5.3, this has changed: print(tostring(10)) — “10” print(tostring(10.0)) — “10.0” That’s because Lua 5.3 introduced the integer subtype. From Changes in the Language: The conversion of a float to a string now adds a .0 suffix to the result … Read more
I had a similar issue. I ran :TSUpdate in Neovim to update Treesitter plugin and the error message disapear after relaunching.
Both are local.
This should work exactly as you expect it to. In lua ‘==’ for string will return true if contents of the strings are equal. As it was pointed out in the comments, lua strings are interned, which means that any two strings that have the same value are actually the same string.
This is a more elegant way: function script_path() local str = debug.getinfo(2, “S”).source:sub(2) return str:match(“(.*/)”) end print(script_path())
A table in Lua is a set of key-value mappings with unique keys. The pairs are stored in arbitrary order and therefore the table is not sorted in any way. What you can do is iterate over the table in some order. The basic pairs gives you no guarantee of the order in which the … Read more
I can’t speak to Lua but for Javascript, Caja has tooling to create a proper sandbox, limiting access to only certain functions. It was originally created to build a sandbox for HTML/JS widgets (like those used on iGoogle). http://code.google.com/p/google-caja/ Here’s a description of the project from their homepage: Caja (pronounced “KA-ha”), is a Spanish word … Read more
There is no standard Lua package management system, but you can try out the following: LuaRocks – contains a rather large number of Lua modules distributed as rocks. Once LuaRocks is installed, the installation is simple: luarocks install desired-package. On Linux/Unix/Mac, this will install into /usr/local/{share,lib}/lua/5.1, where the Lua interpreter looks for modules. LuaDist – … Read more
Use #: > a = {10, 11, 12, 13} > print(#a) 4 Notice however that the length operator # does not work with tables that are not arrays, it only counts the number of elements in the array part (with indices 1, 2, 3 etc.). This won’t work: > a = {1, 2, [5] = … Read more