IsLambda

IsLambda( value )
IsLambda( value )
IsLambda( value )
IsLambda( value )
Not available in this language yet.
Not available in this language yet.

Description

The IsLambda function returns true only if value is a Lambda function, otherwise it returns false.

Parameters

Argument Type Definition and Requirements

value

Any

Any value, which is to be tested to determine whether it is a Lambda function or not.

Returns

Returns a boolean, indicating whether value was a Lambda function 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 IsLambda with that value:

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"),
      "IsLambda": f.IsLambda(f.Var("x")),
    })))

if (err != nil) {
  fmt.Println(err)
} else {
  fmt.Println(result)
}
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"), "IsLambda", IsLambda(Var("x")))
            )
        )
    ).get());
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'),
      IsLambda: q.IsLambda(q.Var('x')),
    })
  )
)
.then((ret) => console.log(ret))
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"), "IsLambda" -> IsLambda(Var("x")))
      )
    )
  ),
  5.seconds
))
Not available in this language yet.
Not available in this language yet.
[map[IsLambda:false value:[array]] map[IsLambda:false value:true] map[IsLambda:false value:false] map[IsLambda:false value:[1 2 3 4]] map[IsLambda:false value:[1 2 3 4]] map[IsLambda:false value:{Letters 0xc00009a390 0xc00009a390 <nil>}] map[IsLambda:false value:{264354436692836874 0xc00009a4b0 0xc00009a4b0 <nil>}] map[IsLambda:false value:{child_db 0xc00009a6f0 0xc00009a6f0 <nil>}] map[IsLambda:false value:{0 63709113600 <nil>}] map[IsLambda:false value:{123 0xc00009a900 0xc00009a900 <nil>}] map[IsLambda:false value:10.1] map[IsLambda:false value:{double 0xc00009aa50 0xc00009aa50 <nil>}] map[IsLambda:false value:{all_letters 0xc00009ab70 0xc00009ab70 <nil>}] map[IsLambda:false value:10] map[IsLambda:false value:{248967241620521472 0xc00009acc0 0xc00009acc0 <nil>}] map[IsLambda:true 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[IsLambda:false value:{}] map[IsLambda:false value:{}] map[IsLambda:false value:map[x:10]] map[IsLambda:false value:{employees 0xc00009aed0 0xc00009aed0 <nil>}] map[IsLambda:false value:{map[match:{all_letters 0xc00009b020 0xc00009b020 <nil>}]}] map[IsLambda:false value:ten] map[IsLambda:false value:10] map[IsLambda:false value:{641563000 63724302465 <nil>}] map[IsLambda:false value:{249062079147803136 0xc00009b1d0 0xc00009b1d0 <nil>}]]
[{value: ["array"], IsLambda: false},
 {value: true, IsLambda: false},
 {value: false, IsLambda: false},
 {value: [0x01 0x02 0x03 0x04], IsLambda: false},
 {value: [1, 2, 3, 4], IsLambda: false},
 {value: ref(id = "Letters", collection = ref(id = "collections")),
  IsLambda: false},
 {value: ref(id = "248967019900174848", collection = ref(id = "credentials")),
  IsLambda: false},
 {value: ref(id = "child_db", collection = ref(id = "databases")),
  IsLambda: false},
 {value: 2019-11-12, IsLambda: false},
 {value: ref(id = "123", collection = ref(id = "Letters", collection = ref(id = "collections"))),
  IsLambda: false},
 {value: 10.1, IsLambda: false},
 {value: ref(id = "double", collection = ref(id = "functions")),
  IsLambda: false},
 {value: ref(id = "all_letters", collection = ref(id = "indexes")),
  IsLambda: false},
 {value: 10, IsLambda: false},
 {value: ref(id = "248967241620521472", collection = ref(id = "keys")),
  IsLambda: false},
 {value: QueryV({lambda=x, expr={var=x}}), IsLambda: true},
 {value: null, IsLambda: false},
 {value: {x: 10}, IsLambda: false},
 {value: ref(id = "employees", collection = ref(id = "roles")),
  IsLambda: false},
 {value: {@set = {match: ref(id = "all_letters", collection = ref(id = "indexes"))}},
  IsLambda: false},
 {value: "ten", IsLambda: false},
 {value: "10", IsLambda: false},
 {value: 2019-11-12T13:15:16.789Z, IsLambda: false},
 {value: ref(id = "249062079147803136", collection = ref(id = "tokens")),
  IsLambda: false}]
[ { value: [ 'array' ], IsLambda: false },
  { value: true, IsLambda: false },
  { value: false, IsLambda: false },
  { value: Bytes("AQIDBA=="), IsLambda: false },
  { value: [ 1, 2, 3, 4 ], IsLambda: false },
  { value: Collection("Letters"), IsLambda: false },
  { value: Ref(Credentials(), "248967019900174848"),
    IsLambda: false },
  { value: Database("child_db"), IsLambda: false },
  { value: Date("2019-11-12"), IsLambda: false },
  { value: Ref(Collection("Letters"), "123"), IsLambda: false },
  { value: 10.1, IsLambda: false },
  { value: Function("double"), IsLambda: false },
  { value: Index("all_letters"), IsLambda: false },
  { value: 10, IsLambda: false },
  { value: Ref(Keys(), "248967241620521472"), IsLambda: false },
  { value: Query(Lambda("x", Var("x"))), IsLambda: true },
  { value: null, IsLambda: false },
  { value: { x: 10 }, IsLambda: false },
  { value: Role("employees"), IsLambda: false },
  { value: Match(Index("all_letters")), IsLambda: false },
  { value: 'ten', IsLambda: false },
  { value: '10', IsLambda: false },
  { value: Time("2019-11-12T13:15:16.789Z"), IsLambda: false },
  { value: Ref(Tokens(), "249062079147803136"), IsLambda: false } ]
[{value: ["array"], IsLambda: false},
 {value: true, IsLambda: false},
 {value: false, IsLambda: false},
 {value: [0x01 0x02 0x03 0x04], IsLambda: false},
 {value: [1, 2, 3, 4], IsLambda: false},
 {value: ref(id = "Letters", collection = ref(id = "collections")),
  IsLambda: false},
 {value: ref(id = "248967019900174848", collection = ref(id = "credentials")),
  IsLambda: false},
 {value: ref(id = "child_db", collection = ref(id = "databases")),
  IsLambda: false},
 {value: 2019-11-12, IsLambda: false},
 {value: ref(id = "123", collection = ref(id = "Letters", collection = ref(id = "collections"))),
  IsLambda: false},
 {value: 10.1, IsLambda: false},
 {value: ref(id = "double", collection = ref(id = "functions")),
  IsLambda: false},
 {value: ref(id = "all_letters", collection = ref(id = "indexes")),
  IsLambda: false},
 {value: 10, IsLambda: false},
 {value: ref(id = "248967241620521472", collection = ref(id = "keys")),
  IsLambda: false},
 {value: {lambda: "x", expr: {var: "x"}}, IsLambda: true},
 {value: NullV, IsLambda: false},
 {value: {x: 10}, IsLambda: false},
 {value: ref(id = "employees", collection = ref(id = "roles")),
  IsLambda: false},
 {value: {@set = {match: ref(id = "all_letters", collection = ref(id = "indexes"))}},
  IsLambda: false},
 {value: "ten", IsLambda: false},
 {value: "10", IsLambda: false},
 {value: 2019-11-12T13:15:16.789Z, IsLambda: false},
 {value: ref(id = "249062079147803136", collection = ref(id = "tokens")),
  IsLambda: 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.

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