Re: read in script vs compiled

[Per Bothner <per@bothner.com>]

On 03/09/2017 03:19 PM, Peter Lane wrote:
> Hi,
>
> I may be misunderstanding something here about how the jvm uses terminal input, and how that interacts with Kawa.
>
> I am trying to get some user input from the terminal in a script, but I receive Null pointer errors with Kawa.  On a little investigation, Kawa does not seem to like input entered from the terminal, but is ok with input from a redirected file or when compiled to a class file and run with java, or in the REPL.  (I'm using bash under ubuntu.)
>> ...
> But I get an exception if I use kawa to run the .class file, or if I run the .scm file as a script:
>
> $ kawa read.scm
> 1
> java.lang.NullPointerException
>     at gnu.expr.Compilation.getFileName(Compilation.java:2641)

There is some awkwardness is how Kawa communicates with the JLine
input editor.  (The complication is because we want to handle multi-line
inputs.)

What needs to happen is that the JLineInPort.parse methods needs to
know if we're reading forms (expressions) or "data".  That shouldn't
be very hard, but it is probably a bit "fiddly" figuring out the
right way to do it.

As a work-around, you can disable jline input-editing:

$ kawa console:use-jline=no read.scm
-- 
	--Per Bothner
per@bothner.com   http://per.bothner.com/