adding support for OrderBy and Limit in MyriaL

[jortiz16]

• added support for OrderBy in Myrial (but must be paired with a Limit operator). Can support queries with this syntax:

T1 = [from scan(TwitterK) as t ORDERBY $0 ASC, $1 DESC emit *];
T2 = LIMIT(T1,50);
store(T2, TwitterKOrdered);)

I wasn't sure if we wanted to use the ASC or DESC keywords in MyriaL, but I added them there for now. If neither ASC or DESC are described, we order ascending by default.

• added new rule to push a Collect operator below the OrderBy

[coveralls]

Coverage decreased (-0.07%) to 91.585% when pulling c096a11b922a4ab4afff4097a08cb10911c9036d on orderbyForMyriaL into 39ac6b73c9f0c399f0942d143e34bdb5afe563b2 on master.

[jortiz16]

@senderista Still going to fix the ORDER BY in the grammar and add LIMIT as well. Will add them soon

[jortiz16]

@senderista The Travis tests aren't passing, but I'm having the same issue as the Master branch. Do you know what the issue could be?

@jingjingwang Your recent branch is passing. Are you pushing a fix for this?

Thanks!

[jortiz16]

Any insight on the Raco/Travis issue on master I mentioned earlier? @senderista @jingjingwang

[senderista]

My guess is that the Travis error is from gcc being invoked instead of clang.

[senderista]

Travis is passing in master now.

[jortiz16]

Great, thanks!

[coveralls]

Coverage decreased (-0.05%) to 91.613% when pulling 06bc83ec5f2cf19d5a3c7ddfaad1b42f42fd8092 on orderbyForMyriaL into 322ea49960518dd47525d484608bab80eecef923 on master.

[coveralls]

Coverage increased (+0.01%) to 91.676% when pulling 3a73ff0c1cabf4ac88d34ef0ef9fc2395e3a93c1 on orderbyForMyriaL into 322ea49960518dd47525d484608bab80eecef923 on master.

[coveralls]

Coverage increased (+0.04%) to 91.7% when pulling f9e26292c07b6f38bb53bb8cfe75c97fef8cd0aa on orderbyForMyriaL into 322ea49960518dd47525d484608bab80eecef923 on master.

[coveralls]

Coverage increased (+0.04%) to 91.7% when pulling f6616b3fe13551a7b89c3bda383fe5c071505584 on orderbyForMyriaL into 322ea49960518dd47525d484608bab80eecef923 on master.

[jortiz16]

sounds good, thanks!