Support for parsing negative numbers

[serba]

In my project I need ability to pass negative numbers as option arguments, but unfortunately it doesn't work. It seems parser treats negative numbers as options themselves.

You can easily reproduce this by changing TestPrimitiveExample test (see "Option must have a value: --int value" failure)

--- a/jewelcli/src/test/java/com/lexicalscope/jewel/cli/examples/TestPrimitiveExample.java
+++ b/jewelcli/src/test/java/com/lexicalscope/jewel/cli/examples/TestPrimitiveExample.java
@@ -13,7 +13,7 @@ public class TestPrimitiveExample {
                 new String[] { "--boolean",
                          "--byte", "1",
                          "--short", "2",
-                         "--int", "3",
+                         "--int", "-3",
                          "--long", "4",
                          "--float", "4.1",
                          "--double", "4.2",

[lexicalscope]

Ok, that is an interesting use case. I'm not quite sure how to handle this case as the parsing phase is not directed by the actual option specifications at the moment; so it can't tell if "-3" is supposed to be the value negative 3 or the option "3". I wonder what the solution is.

[lexicalscope]

Workaround: One thing you can do in meantime I think, is specify the command line using the "=" syntax like this "--int=-3"

[serba]

Tim,

Thank you very much for the workaround!

Re general solution - I'm not sure, but I've seen other parsers (jcommander, jopt) do handle that scenario somehow. Are numerical option names valid in posix/gnu?

[okorz001]

Numerical short options are traditionally valid although uncommon, e.g. ssh has -4 and -6. However, I think that if an option requires a value, the next argument should always be eagerly consumed, since the option parser cannot make assumptions about which values are valid (outside of type conversion failures).