lostanza docs

[callendorph]

Calling lostanza from repl

This works:

lostanza let :
  call-c clib/printf("Hello world\n")

Don't use pointers to variables on the stack

public lostanza defn libarchive_read_data_block (p:ref<LIBARCHIVE>, pbuf:ptr<ptr<?>>, psize:ptr<long>, poffset:ptr<long>) -> ref<Long> :
  var xbuf:ptr<?>
  var xs:long
  var xo:long
  val rtn:long = call-c archive_read_data_block(p.la-ptr, addr(xbuf), addr(xs), addr(xo))
  return new Long{0}

This throws:

FATAL ERROR: No appropriate branch for arguments of type (Int).
  in core/print-stack-trace
    at core/core.stanza:344.14
  in core/fatal
    at core/core.stanza:397.2
  in core/no-branch-error
    at core/core.stanza:274.2
  in stz/el-to-vm/Compiler/imms!
    at compiler/el-to-vm.stanza:793.10
...

This is because we can't create pointers to values on the stack. Need to use malloc/free to create them on the heap.

[callendorph]

Also we should document the null value as a defined item in core.