* better sys .file
  * don't make newly opened files executable by default
    * make :executable, :nonexecutable, :writable, :readable, etc.
  * apply :readwrite by default on :creating
* apply the trace extractor to non-tail situations
* reduze ./optimized binary size (clean up lib/sys/opt.ey code)
* inline trivial functions when optimizer generates ... /rax :movqImmReg /rax :callqReg sequence
* parse }" created constant pushers into PUSH in optimizer
* hunt the }"s down
* don't allocate ints for syscalls if not necessary
* *THISSCOPE could also work with PUSH
* handle huge objects better (and move them out of linear heap space)
* make map work on non-strings, too
* utf8
* regex substitution
* asm-based regex engine
* [,] must be escapable in regex
* txt .consume .u sollte nicht negative Zahlen liefern
  * evtl. BigNums bauen und die Int-Funktionen entsprechend machen
* trigonometrics
* create sys .posix
* port the sys functions to FreeBSD
* stack traces with function source
  * make it possible to put comments into the stacktrace for iteration over non-uniform objects

* testsuite (incl. coverage test)
  * what is broken with working-loaded/sort.test

* make '' applicable to arrays, too, i.e. save input type

* consider polymorphic call-site caches instead of deffs_t_ / deffs?

* eliminate all FIXMEs
* stack underflow protection
* input prompt
* better interactive error handling when interpreting from stdin
* document ALL THE LIBRARIES
* consider https://en.wikipedia.org/wiki/Hindley%E2%80%93Milner_type_system and finally make the stuff typed correctly

* on fatal resolution failure, try parent scopes to see whether it's a simple typo (levenstein)

* Why is `parse quartfull` in igor taking significant time? Java LR(0) parser allegedly takes 0.001s.