General steps, step-modulators, and predicates

Apache TinkerPop^TM has five general step types:

map(Traversal<S,E>) or map(Function<Traverser<S>, E>)

Maps the traverser to some object of type E for the next step to process.

flatMap(Traversal<S,E>) or flatMap(Function<Traverser<S>, Iterator<E>)

Maps the traverser to an iterator of E objects that are streamed to the next step.

filter(Traversal<?, ?>) or filter(Predicate<Traverser<S>>)

Maps the traverser to either true or false, and where false will not pass the traverser to the next step.

sideEffect(Traversal<S, S>) or sideEffect(Consumer<Traverser<S>>)

Performs some operation on the traverser and passes it to the next step.

branch(Traversal<S, M>) or branch(Function<Traverser<S>, M>)

Splits the traverser to all the traversals indexed by the M token.

All other steps in the reference can be categorized as one of these steps or a variant, such as a terminal step that completes a traversal. In addition, steps have step-modulators, a helper step that assists a step:

as()

Provide a label to the step that can later be accessed by steps and data structures that make use of such labels.

by()

If a step is able to accept traversals, functions, or comparators, then by() is the means by which they are added.

emit()

If emit() is placed after repeat(), it is evaluated on the traversers leaving the repeat-traversal. If emit() is placed before repeat(), it is evaluated on the traversers prior to entering the repeat-traversal.

from()

Adds a string or traversal to a traversal to point the traversal FROM the next supplied step.

option()

Provide a option to a branch() or choose() step.

to()

Adds a string or traversal to a traversal to point the traversal TO the next supplied step.

until()

If until() comes after repeat() it is do/while looping. If until() comes before repeat() it is while/do looping.

Within steps, predicates are used to determine relationships between data:

eq(object)

Check if an incoming object is equal to the provided object.

neq(object)

Check if an incoming object is not equal to the provided object.

lt(number)

Check if an incoming number is less than the provided number.

lte(number)

Check if an incoming number is less than or equal the provided number.

gt(number)

Check if an incoming number is greater than the provided number.

gte(number)

Check if an incoming number is greater than or equal the provided number.

inside(number, number)

Check if an incoming number is inside the range of the provided numbers.

outside(number, number)

Check if an incoming number is outside the range of the provided numbers.

between(number, number)

Check if an incoming number is greater than or equal to the first provided number and less than the second provided number.

within(objects...)

Check if an incoming object is within an array of provided objects.

without(objects...)

Check if an incoming object is not within an array of provided objects.