String slicing with negative indices throws an error

[juliajohannesen]

Slicing a string with a negative index, results in an error:

"foo"[1:-1]
RUNTIME ERROR: got [1:-1:1] but negative index, end, and steps are not supported
	std.jsonnet:(220:5)-(234:66)	function <anonymous>
	<stdin>:1:1-12	

Compare this to both go-jsonnet and jrsonnet, which result in the following:

"foo"[1:-1]
"o"

jsonnet --version output (for the failing implementation):

Jsonnet commandline interpreter v0.20.0

[johnbartholomew]

Thanks for the report, however version 0.20.0 does not support negative slice indexes. It was added in #1093 and is included in the v0.21.0-rc1 release candidate.

[juliajohannesen]

Ah, gotcha! Thanks!