IsFunction

IsFunction( value )
IsFunction( value )
IsFunction( value )
IsFunction( value )
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Description

The IsFunction function returns true only if value is a 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 function or not.

Returns

Returns a boolean, indicating whether value was a 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 IsFunction 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"),
      "IsFunction": f.IsFunction(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"), "IsFunction", IsFunction(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'),
      IsFunction: q.IsFunction(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"), "IsFunction" -> IsFunction(Var("x")))
      )
    )
  ),
  5.seconds
))
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Not available in this language yet.
Not available in this language yet.
[map[IsFunction:false value:[array]] map[IsFunction:false value:true] map[IsFunction:false value:false] map[IsFunction:false value:[1 2 3 4]] map[IsFunction:false value:[1 2 3 4]] map[IsFunction:false value:{Letters 0xc0000b8d50 0xc0000b8d50 <nil>}] map[IsFunction:false value:{264354436692836874 0xc0000b9200 0xc0000b9200 <nil>}] map[IsFunction:false value:{child_db 0xc0000b9380 0xc0000b9380 <nil>}] map[IsFunction:false value:{0 63709113600 <nil>}] map[IsFunction:false value:{123 0xc0000b9590 0xc0000b9590 <nil>}] map[IsFunction:false value:10.1] map[IsFunction:true value:{double 0xc0000b96e0 0xc0000b96e0 <nil>}] map[IsFunction:false value:{all_letters 0xc0000b9800 0xc0000b9800 <nil>}] map[IsFunction:false value:10] map[IsFunction:false value:{248967241620521472 0xc0000b9950 0xc0000b9950 <nil>}] map[IsFunction: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[IsFunction:false value:{}] map[IsFunction:false value:{}] map[IsFunction:false value:map[x:10]] map[IsFunction:false value:{employees 0xc0000b9b60 0xc0000b9b60 <nil>}] map[IsFunction:false value:{map[match:{all_letters 0xc0000b9cb0 0xc0000b9cb0 <nil>}]}] map[IsFunction:false value:ten] map[IsFunction:false value:10] map[IsFunction:false value:{744903000 63724302339 <nil>}] map[IsFunction:false value:{249062079147803136 0xc0000b9e60 0xc0000b9e60 <nil>}]]
[{value: ["array"], IsFunction: false},
 {value: true, IsFunction: false},
 {value: false, IsFunction: false},
 {value: [0x01 0x02 0x03 0x04], IsFunction: false},
 {value: [1, 2, 3, 4], IsFunction: false},
 {value: ref(id = "Letters", collection = ref(id = "collections")),
  IsFunction: false},
 {value: ref(id = "248967019900174848", collection = ref(id = "credentials")),
  IsFunction: false},
 {value: ref(id = "child_db", collection = ref(id = "databases")),
  IsFunction: false},
 {value: 2019-11-12, IsFunction: false},
 {value: ref(id = "123", collection = ref(id = "Letters", collection = ref(id = "collections"))),
  IsFunction: false},
 {value: 10.1, IsFunction: false},
 {value: ref(id = "double", collection = ref(id = "functions")),
  IsFunction: true},
 {value: ref(id = "all_letters", collection = ref(id = "indexes")),
  IsFunction: false},
 {value: 10, IsFunction: false},
 {value: ref(id = "248967241620521472", collection = ref(id = "keys")),
  IsFunction: false},
 {value: QueryV({lambda=x, expr={var=x}}), IsFunction: false},
 {value: null, IsFunction: false},
 {value: {x: 10}, IsFunction: false},
 {value: ref(id = "employees", collection = ref(id = "roles")),
  IsFunction: false},
  {value: {@set = {match: ref(id = "all_letters", collection = ref(id = "indexes"))}},
  IsFunction: false},
 {value: "ten", IsFunction: false},
 {value: "10", IsFunction: false},
 {value: 2019-11-12T13:15:16.789Z, IsFunction: false},
 {value: ref(id = "249062079147803136", collection = ref(id = "tokens")),
  IsFunction: false}]
[ { value: [ 'array' ], IsFunction: false },
  { value: true, IsFunction: false },
  { value: false, IsFunction: false },
  { value: Bytes("AQIDBA=="), IsFunction: false },
  { value: [ 1, 2, 3, 4 ], IsFunction: false },
  { value: Collection("Letters"), IsFunction: false },
  { value: Ref(Credentials(), "248967019900174848"),
    IsFunction: false },
  { value: Database("child_db"), IsFunction: false },
  { value: Date("2019-11-12"), IsFunction: false },
  { value: Ref(Collection("Letters"), "123"), IsFunction: false },
  { value: 10.1, IsFunction: false },
  { value: Function("double"), IsFunction: true },
  { value: Index("all_letters"), IsFunction: false },
  { value: 10, IsFunction: false },
  { value: Ref(Keys(), "248967241620521472"), IsFunction: false },
  { value: Query(Lambda("x", Var("x"))), IsFunction: false },
  { value: null, IsFunction: false },
  { value: { x: 10 }, IsFunction: false },
  { value: Role("employees"), IsFunction: false },
  { value: Match(Index("all_letters")), IsFunction: false },
  { value: 'ten', IsFunction: false },
  { value: '10', IsFunction: false },
  { value: Time("2019-11-12T13:15:16.789Z"), IsFunction: false },
  { value: Ref(Tokens(), "249062079147803136"),
    IsFunction: false } ]
[{value: ["array"], IsFunction: false},
 {value: true, IsFunction: false},
 {value: false, IsFunction: false},
 {value: [0x01 0x02 0x03 0x04], IsFunction: false},
 {value: [1, 2, 3, 4], IsFunction: false},
 {value: ref(id = "Letters", collection = ref(id = "collections")),
  IsFunction: false},
 {value: ref(id = "248967019900174848", collection = ref(id = "credentials")),
  IsFunction: false},
 {value: ref(id = "child_db", collection = ref(id = "databases")),
  IsFunction: false},
 {value: 2019-11-12, IsFunction: false},
 {value: ref(id = "123", collection = ref(id = "Letters", collection = ref(id = "collections"))),
  IsFunction: false},
 {value: 10.1, IsFunction: false},
 {value: ref(id = "double", collection = ref(id = "functions")),
  IsFunction: true},
 {value: ref(id = "all_letters", collection = ref(id = "indexes")),
  IsFunction: false},
 {value: 10, IsFunction: false},
 {value: ref(id = "248967241620521472", collection = ref(id = "keys")),
  IsFunction: false},
 {value: {lambda: "x", expr: {var: "x"}}, IsFunction: false},
 {value: NullV, IsFunction: false},
 {value: {x: 10}, IsFunction: false},
 {value: ref(id = "employees", collection = ref(id = "roles")),
  IsFunction: false},
 {value: {@set = {match: ref(id = "all_letters", collection = ref(id = "indexes"))}},
  IsFunction: false},
 {value: "ten", IsFunction: false},
 {value: "10", IsFunction: false},
 {value: 2019-11-12T13:15:16.789Z, IsFunction: false},
 {value: ref(id = "249062079147803136", collection = ref(id = "tokens")),
  IsFunction: 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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