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The previously deprecated `Order.incr` and `Order.decr` were completely removed in TinkerPop 3.5.0. The manuscript needs to be updated to favor `Order.asc` and `Order.desc` and the note about the deprecation needs...

krlawrence

Discuss the fact that a null value can now flow through a traversal which alleviates the need to often do `coalesce(x, constant(0))` type tricks. ``` gremlin> g.V('3').project('x').by('IDoNotExist') ==>[x:null] ``` Also...

krlawrence

This seemingly simple task cannot be done using a `has` step and users get confused when trying to do something like this: ``` gremlin> g.addV('test').property('a',5).property('b',10) ==>v[53770] gremlin> g.V().hasLabel('test').as('x').where(gt('x')).by('b').by('a') ==>v[53767] ```...

krlawrence

Gremlin does not have a `reverse` step but a list can be reversed using the `index` step couples with `order` and `tail` It is possible to do this today using...

krlawrence

The book currently has examples of vertex cloning but does not have any examples of how to merge two vertices and re-map their edges.

krlawrence

Add an example where a value found in one vertex is used to do `startingWith` searches across other vertices. ``` gremlin> g.addV('key').property('prefix','Dal') ==>v[60873] gremlin> g.V().hasLabel('key').as('a').V().hasLabel('airport').where(startingWith('a')).by('city').by('prefix'). values('city') ==>Dallas ==>Dallas ==>Dalaman ==>Dalian...

krlawrence

For the example shown here: https://kelvinlawrence.net/book/Gremlin-Graph-Guide.html#upsert This would be simpler if written as below since the same property value is being set. ``` g.V(3).fold(). coalesce(unfold(), addV('airport')).property('runways',3) ``` It would also...

bechbd

Add an example of using coalesce() inside a by() modulator.

1

Should add an example that shows that this is possible ``` gremlin> g.V(0,3).project('city').by(coalesce(values('city'),constant('not found'))) ==>[city:not found] ==>[city:Austin] ```

krlawrence

Since the data set was first created several cities have been added that have a name longer than the 20 characters allowed by the VARCHAR(20) in the airports table. Sqlite3...

krlawrence

Add an example near section 4.16 showing how to merge two valueMap results For example ``` gremlin> g.V(3,4).valueMap().unfold().group().by(keys).by(select(values).unfold().fold()) ==>[country:[US,US],code:[AUS,BNA],longest:[12250,11030],city:[Austin,Nashville],elev:[542,599],icao:[KAUS,KBNA],lon:[ -97.6698989868164,-86.6781997680664],type:[airport,airport],region:[US-TX,US-TN],runways:[2,4],lat:[30.1944999694824,3 6.1245002746582],desc:[Austin Bergstrom International Airport,Nashville International Airport]] ```

krlawrence