Why parsing Gremlin query in Java isn't generic? -


i'm parsing gremlin query in java (well, i'm writing scala, , using groovy compiled jars java).

the query string variable given user input. in other words - cannot tell query be, i'm assuming it's valid gremlin query (syntactically , logically).

i started simple gremlin.compile(query) returns pipe on i'm iterating. however, according the example, 1 must invoke .setstarts prior iterating pipe. , must know runtime type s in pipe<s,e>.

it feels api isn't generic enough, following line example

pipe.setstarts(new singleiterator<vertex>(graph.getvertex(1)));

will work cases, vertex iteration 1 example (g.v()) throw castexception.

is there way work-around it?

perhaps using underlying script engine (like next examples in link above) me achieve more generic code?

i found workaround. feels bit ugly job.

  1. i'm using scriptengine bindings of 'g' graph, user can start his/her queries g.. (not helps generics, makes more user-friendly not making user use identity pipe (_()) @ beginning of his/her queries).

  2. (kind of ugly, know) i'm extracting query string (using regex) starting vertex (if exists), finding programatically , (if found) invoking setstarts it. if it's not found i'm giving graph parameter setstarts, assuming vertex iteration query.


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