Evaluate Lua expression {expr} and return its result converted to Vim data structures. Second {expr} may hold additional argument accessible as _A inside first {expr}. Strings are returned as they are. Boolean objects are converted to numbers. Numbers are converted to |Float| values if vim was compiled with |+float| and to numbers otherwise. Dictionaries and lists obtained by vim.eval() are returned as-is. Other objects are returned as zero without any errors. See |lua-luaeval| for more details. Note that in a :def function local variables are not visible to {expr}. Can also be used as a |method|: GetExpr()->luaeval() {only available when compiled with the |+lua| feature}