IsIndex

Not available in this language yet.

IsIndex( value )

IsIndex( value )

IsIndex( value )

Not available in this language yet.

IsIndex( value )

Description

The IsIndex function returns true only if value is an index, otherwise it returns false.

Parameters

Argument Type Definition and Requirements

Argument	Type	Definition and Requirements
`value`	Any	Any value, which is to be tested to determine whether it is an index or not.

value

Any

Any value, which is to be tested to determine whether it is an index or not.

Returns

Returns a boolean, indicating whether value was an index or not.

Examples

The following query uses Map to iterate over an array of all of the types of values that can be tested by a type-check function, passing each item into a Lambda function that returns an object, which contains the value and the result of calling IsIndex with that value:

Not available in this language yet.

result, err := client.Query(
  f.Map(
    f.Arr{
      f.Arr{"array"},
      true,
      false,
      f.BytesV{0x01, 0x02, 0x03, 0x04},
      f.Arr{0x1, 0x2, 0x3, 0x4},
      f.Collection("Letters"),
      f.Ref("credentials/self"),
      f.Database("child_db"),
      f.Date("2019-11-12"),
      f.RefCollection(f.Collection("Letters"), 123),
      10.1,
      f.Function("double"),
      f.Index("all_letters"),
      10,
      f.RefCollection(f.Keys(), "248967241620521472"),
      f.Query(f.Lambda("x", f.Var("x"))),
      nil,
      f.Null(),
      f.Obj{ "x": 10 },
      f.Role("employees"),
      f.Match(f.Index("all_letters")),
      "ten",
      "10",
      f.Now(),
      f.RefCollection(f.Tokens(), "249062079147803136"),
    },
    f.Lambda("x", f.Obj{
      "value": f.Var("x"),
      "IsIndex": f.IsIndex(f.Var("x")),
    })))

if (err != nil) {
  fmt.Println(err)
} else {
  fmt.Println(result)
}

[map[IsIndex:false value:[array]] map[IsIndex:false value:true] map[IsIndex:false value:false] map[IsIndex:false value:[1 2 3 4]] map[IsIndex:false value:[1 2 3 4]] map[IsIndex:false value:{Letters 0xc000134330 0xc000134330 <nil>}] map[IsIndex:false value:{264354436692836874 0xc000134450 0xc000134450 <nil>}] map[IsIndex:false value:{child_db 0xc000134570 0xc000134570 <nil>}] map[IsIndex:false value:{0 63709113600 <nil>}] map[IsIndex:false value:{123 0xc000134780 0xc000134780 <nil>}] map[IsIndex:false value:10.1] map[IsIndex:false value:{double 0xc0001348d0 0xc0001348d0 <nil>}] map[IsIndex:true value:{all_letters 0xc0001349f0 0xc0001349f0 <nil>}] map[IsIndex:false value:10] map[IsIndex:false value:{248967241620521472 0xc000134b40 0xc000134b40 <nil>}] map[IsIndex:false value:{[123 34 108 97 109 98 100 97 34 58 34 120 34 44 34 101 120 112 114 34 58 123 34 118 97 114 34 58 34 120 34 125 125]}] map[IsIndex:false value:{}] map[IsIndex:false value:{}] map[IsIndex:false value:map[x:10]] map[IsIndex:false value:{employees 0xc000134d50 0xc000134d50 <nil>}] map[IsIndex:false value:{map[match:{all_letters 0xc000134ea0 0xc000134ea0 <nil>}]}] map[IsIndex:false value:ten] map[IsIndex:false value:10] map[IsIndex:false value:{358249000 63724302394 <nil>}] map[IsIndex:false value:{249062079147803136 0xc000135050 0xc000135050 <nil>}]]

System.out.println(
    client.query(
        Map(
            Arr(
                Arr(Value("array")),
                Value(true),
                Value(false),
                Value(new byte[] {0x1, 0x2, 0x3, 0x4}),
                Arr(Value(0x1), Value(0x2), Value(0x3), Value(0x4)),
                Collection("Letters"),
                Ref("credentials/self"),
                Database("child_db"),
                Date("2019-11-12"),
                Ref(Collection("Letters"), "123"),
                Value(10.1),
                Function("double"),
                Index("all_letters"),
                Value(10),
                Ref(Keys(), "248967241620521472"),
                Query(Lambda("x", Var("x"))),
                Null(),
                Obj("x", Value(10)),
                Role("employees"),
                Match(Index("all_letters")),
                Value("ten"),
                Value("10"),
                Now(),
                Ref(Tokens(), "249062079147803136")
            ),
            Lambda(
                "x",
                Obj("value", Var("x"), "IsIndex", IsIndex(Var("x")))
            )
        )
    ).get());

[{value: ["array"], IsIndex: false},
 {value: true, IsIndex: false},
 {value: false, IsIndex: false},
 {value: [0x01 0x02 0x03 0x04], IsIndex: false},
 {value: [1, 2, 3, 4], IsIndex: false},
 {value: ref(id = "Letters", collection = ref(id = "collections")),
  IsIndex: false},
 {value: ref(id = "248967019900174848", collection = ref(id = "credentials")),
  IsIndex: false},
 {value: ref(id = "child_db", collection = ref(id = "databases")),
  IsIndex: false},
 {value: 2019-11-12, IsIndex: false},
 {value: ref(id = "123", collection = ref(id = "Letters", collection = ref(id = "collections"))),
  IsIndex: false},
 {value: 10.1, IsIndex: false},
 {value: ref(id = "double", collection = ref(id = "functions")),
  IsIndex: false},
 {value: ref(id = "all_letters", collection = ref(id = "indexes")),
  IsIndex: true},
 {value: 10, IsIndex: false},
 {value: ref(id = "248967241620521472", collection = ref(id = "keys")),
  IsIndex: false},
 {value: QueryV({lambda=x, expr={var=x}}), IsIndex: false},
 {value: null, IsIndex: false},
 {value: {x: 10}, IsIndex: false},
 {value: ref(id = "employees", collection = ref(id = "roles")),
  IsIndex: false},
 {value: {@set = {match: ref(id = "all_letters", collection = ref(id = "indexes"))}},
  IsIndex: false},
 {value: "ten", IsIndex: false},
 {value: "10", IsIndex: false},
 {value: 2019-11-12T13:15:16.789Z, IsIndex: false},
 {value: ref(id = "249062079147803136", collection = ref(id = "tokens")),
  IsIndex: false}]

client.query(
  q.Map(
    [
      ['array'],
      true,
      false,
      new Uint8Array([1, 2, 3, 4]),
      [0x1, 0x2, 0x3, 0x4],
      q.Collection('Letters'),
      q.Ref('credentials/self'),
      q.Database('child_db'),
      q.Date('2019-11-12'),
      q.Ref(q.Collection('Letters'), 123),
      10.1,
      q.Function('double'),
      q.Index('all_letters'),
      10,
      q.Ref(q.Keys(), '248967241620521472'),
      q.Query(q.Lambda('x', q.Var('x'))),
      null,
      { x: 10 },
      q.Role('employees'),
      q.Match(q.Index('all_letters')),
      'ten',
      '10',
      q.Now(),
      q.Ref(q.Tokens(), '249062079147803136'),
    ],
    q.Lambda('x', {
      value: q.Var('x'),
      IsIndex: q.IsIndex(q.Var('x')),
    })
  )
)
.then((ret) => console.log(ret))

[ { value: [ 'array' ], IsIndex: false },
  { value: true, IsIndex: false },
  { value: false, IsIndex: false },
  { value: Bytes("AQIDBA=="), IsIndex: false },
  { value: [ 1, 2, 3, 4 ], IsIndex: false },
  { value: Collection("Letters"), IsIndex: false },
  { value: Ref(Credentials(), "248967019900174848"),
    IsIndex: false },
  { value: Database("child_db"), IsIndex: false },
  { value: Date("2019-11-12"), IsIndex: false },
  { value: Ref(Collection("Letters"), "123"), IsIndex: false },
  { value: 10.1, IsIndex: false },
  { value: Function("double"), IsIndex: false },
  { value: Index("all_letters"), IsIndex: true },
  { value: 10, IsIndex: false },
  { value: Ref(Keys(), "248967241620521472"), IsIndex: false },
  { value: Query(Lambda("x", Var("x"))), IsIndex: false },
  { value: null, IsIndex: false },
  { value: { x: 10 }, IsIndex: false },
  { value: Role("employees"), IsIndex: false },
  { value: Match(Index("all_letters")), IsIndex: false },
  { value: 'ten', IsIndex: false },
  { value: '10', IsIndex: false },
  { value: Time("2019-11-12T13:15:16.789Z"), IsIndex: false },
  { value: Ref(Tokens(), "249062079147803136"), IsIndex: false } ]

Not available in this language yet.

println(Await.result(
  client.query(
    Map(
      Arr(
        Arr("array"),
        true,
        false,
        BytesV(0x1, 0x2, 0x3, 0x4),
        Arr(0x1, 0x2, 0x3, 0x4),
        Collection("Letters"),
        Ref("credentials/self"),
        Database("child_db"),
        Date("2019-11-12"),
        Ref(Collection("Letters"), 123),
        10.1,
        Function("double"),
        Index("all_letters"),
        10,
        Ref(Keys(), "248967241620521472"),
        Query(Lambda("x", Var("x"))),
        Null,
        Obj("x" -> 10),
        Role("employees"),
        Match(Index("all_letters")),
        "ten",
        "10",
        Now(),
        Ref(Tokens(), "249062079147803136")
      ),
      Lambda(
        "x",
        Obj( "value" -> Var("x"), "IsIndex" -> IsIndex(Var("x")))
      )
    )
  ),
  5.seconds
))

[{value: ["array"], IsIndex: false},
 {value: true, IsIndex: false},
 {value: false, IsIndex: false},
 {value: [0x01 0x02 0x03 0x04], IsIndex: false},
 {value: [1, 2, 3, 4], IsIndex: false},
 {value: ref(id = "Letters", collection = ref(id = "collections")),
  IsIndex: false},
 {value: ref(id = "248967019900174848", collection = ref(id = "credentials")),
  IsIndex: false},
 {value: ref(id = "child_db", collection = ref(id = "databases")),
  IsIndex: false},
 {value: 2019-11-12, IsIndex: false},
 {value: ref(id = "123", collection = ref(id = "Letters", collection = ref(id = "collections"))),
  IsIndex: false},
 {value: 10.1, IsIndex: false},
 {value: ref(id = "double", collection = ref(id = "functions")),
  IsIndex: false},
 {value: ref(id = "all_letters", collection = ref(id = "indexes")), IsIndex: true},
 {value: 10, IsIndex: false},
 {value: ref(id = "248967241620521472", collection = ref(id = "keys")),
  IsIndex: false},
 {value: {lambda: "x", expr: {var: "x"}}, IsIndex: false},
 {value: NullV, IsIndex: false},
 {value: {x: 10}, IsIndex: false},
 {value: ref(id = "employees", collection = ref(id = "roles")),
  IsIndex: false},
 {value: {@set = {match: ref(id = "all_letters", collection = ref(id = "indexes"))}},
  IsIndex: false},
 {value: "ten", IsIndex: false},
 {value: "10", IsIndex: false},
 {value: 2019-11-12T13:15:16.789Z, IsIndex: false},
 {value: ref(id = "249062079147803136", collection = ref(id = "tokens")),
  IsIndex: false}]

This query operates on a pre-existing schema, which is not provided here.

Also, the query is executed via a client connection, that uses a secret acquired by calling Login (not shown here), so that Ref("credentials/self") returns a valid value.

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!

IsIndex

Description

Parameters

Returns

Examples

Related functions

Keyboard shortcuts

While reading

While searching

URL fragments