Re: suprise with -=

[Bart Schaefer <schaefer@xxxxxxxxxxxxxxxx>]

On Oct 22,  6:43pm, ZyX wrote:
}
} Though I know no language implementations other then VimL (and, maybe,
} tcsh: have not actually seen its source code, but it looks like it is
} also executed in-place) that do not have the parsing stage.

Yes, (t)csh also executes in place, or close to it.  Csh parses one line
at a time, executes it, then parses the next line.  It's not quite as
bad as VimL, but it means that e.g. loops within scripts are implemented
by using fseek to rewind the file pointer to the beginning of the loop.

You can create some really entertaining self-modifying scripts in csh by
having the script rewrite parts of its own source file before they are
read (or re-read, if looping).

Csh is like Gromit in "The Wrong Trousers", laying down his tracks the
instant before the train runs across them.  VimL apparently lays down
the individual railroad ties.