Map
Map( array, lambda )
Map( array, lambda )
Map( array, lambda )
Map( array, lambda )
map_( lambda, array )
Map( array, lambda )
Description
The Map
function iterates on the provided array
, calling the
provided lambda
function repeatedly with each item in array
, and
returns the results of all invocations in a new array of the same type
(an Array or Page).
As Map
processes array
, each invocation of the lambda
function
can see the effects of write operations from previous invocations.
Examples
The following query has a Lambda
which
takes one variable x
, adds 1 to its value, and then returns the
incremented value. This Lambda is executed once for each value in the
array. These values are 1, 2, 3.
client.Query(
Map(Arr(1, 2, 3), x => Add(x, 1))
);
Arr(LongV(2), LongV(3), LongV(4))
result, err := client.Query(
f.Map(f.Arr{1, 2, 3}, f.Lambda("x", f.Add(f.Var("x"), 1))))
if err != nil {
fmt.Fprintln(os.Stderr, err)
} else {
fmt.Println(result)
}
[2 3 4]
System.out.println(
client.query(
Map(
Arr(Value(1), Value(2), Value(3)),
Lambda(Value("x"), Add(Var("x"), Value(1)))
)
).get());
[2, 3, 4]
client.query(
q.Map([1, 2, 3], q.Lambda('x', q.Add(q.Var('x'), 1)))
)
.then((ret) => console.log(ret))
.catch((err) => console.error('Error: %s', err))
[ 2, 3, 4 ]
result = client.query(
q.map_(lambda x: q.add(x, 1), [1, 2, 3])
)
print(result)
[ 2, 3, 4 ]
client.query(Map(Arr(1, 2, 3), Lambda { x => Add(x, 1) }))
[ 2, 3, 4 ]
Is this article helpful?
Tell Fauna how the article can be improved:
Visit Fauna's forums
or email docs@fauna.com
Thank you for your feedback!