Expose Evaluate functions, to be able to reuse the AST from SnippetToAST

[abourget]

Right now, SnippetToAST provides a Node but nothing consumes it it seems.

This is mostly to open the discussion. My goal is to use jsonnet as a reformatter in streaming objects.. Performance is going to be paramount for us, reusing the AST is a start.

Nice work in here by the way.. love the project :)

[coveralls]

Coverage decreased (-0.2%) to 75.192% when pulling d994e6e on abourget:master into 530e796 on google:master.

[coveralls]

Coverage decreased (-0.2%) to 75.192% when pulling d994e6e on abourget:master into 530e796 on google:master.

[seh]

This looks like it might be related to #126.

[abourget]

It is indeed :)

[sparkprime]

@sbarzowski seems ok to me, how about you?

[sbarzowski]

LGTM, since we are exposing AST api and evaluation api, I don't see any reason not to expose AST evaluation API :-)

One day, we may want to extend and clean up that API, with efficient support for evaluating multiple file at once, or the same one multiple times with different TLAs - preserving cached values, especially for imported libs.