returning). There are many styles of asynchronous interfaces: • Callback argument • Return a placeholder (Future, Promise, Deferred) • Deliver to a queue • Callback registry (e.g. POSIX signals) Regardless do not actually make things asynchronous). Asynchronous operations in Tornado generally return placeholder objects (Futures), with the exception of some low- level components like the IOLoop that use callbacks address is a tuple suitable to pass to socket.connect (i.e. a (host, port) pair for IPv4; additional fields may be present for IPv6). If a callback is passed, it will be run with the result as an argument

before returning). There are many styles of asynchronous interfaces: Callback argument Return a placeholder (Future, Promise, Deferred) Deliver to a queue Callback registry (e.g. POSIX signals) Regardless do not actually make things asynchronous). Asynchronous operations in Tornado generally return placeholder objects (Futures), with the exception of some low-level components like the IOLoop that use callbacks python.org/3/library/socket.html#socket.socket.connect] (i.e. a (host, port) pair for IPv4; additional fields may be present for IPv6). If a callback is passed, it will be run with the result as an argument

bindings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1066 55.2 DataType fields . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1066 55.3 Subtypes . tuple is constructed: julia> x = (a=2, b=1+2) (a = 2, b = 3) julia> x[1] 2 julia> x.a 2 The fields of named tuples can be accessed by name using dot syntax (x.a) in addition to the regular indexing that here. You may choose how you wish to handle this exception, whether logging it, return a placeholder value or as in the case below where we just printed out a statement. One thing to think about

bindings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1066 55.2 DataType fields . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1066 55.3 Subtypes . tuple is constructed: julia> x = (a=2, b=1+2) (a = 2, b = 3) julia> x[1] 2 julia> x.a 2 The fields of named tuples can be accessed by name using dot syntax (x.a) in addition to the regular indexing that here. You may choose how you wish to handle this exception, whether logging it, return a placeholder value or as in the case below where we just printed out a statement. One thing to think about

bindings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1247 57.2 DataType fields . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1247 57.3 Subtypes . tuple is constructed: julia> x = (a=2, b=1+2) (a = 2, b = 3) julia> x[1] 2 julia> x.a 2 The fields of named tuples can be accessed by name using dot syntax (x.a) in addition to the regular indexing that here. You may choose how you wish to handle this exception, whether logging it, return a placeholder value or as in the case below where we just printed out a statement. One thing to think about

bindings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1247 57.2 DataType fields . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1247 57.3 Subtypes . tuple is constructed: julia> x = (a=2, b=1+2) (a = 2, b = 3) julia> x[1] 2 julia> x.a 2 The fields of named tuples can be accessed by name using dot syntax (x.a) in addition to the regular indexing that here. You may choose how you wish to handle this exception, whether logging it, return a placeholder value or as in the case below where we just printed out a statement. One thing to think about

bindings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1247 57.2 DataType fields . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1247 57.3 Subtypes . tuple is constructed: julia> x = (a=2, b=1+2) (a = 2, b = 3) julia> x[1] 2 julia> x.a 2 The fields of named tuples can be accessed by name using dot syntax (x.a) in addition to the regular indexing that here. You may choose how you wish to handle this exception, whether logging it, return a placeholder value or as in the case below where we just printed out a statement. One thing to think about

bindings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1300 58.2 DataType fields . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1300CONTENTS x 58.3 Subtypes tuple is constructed: julia> x = (a=2, b=1+2) (a = 2, b = 3) julia> x[1] 2 julia> x.a 2 The fields of named tuples can be accessed by name using dot syntax (x.a) in addition to the regular indexing that here. You may choose how you wish to handle this exception, whether logging it, return a placeholder value or as in the case below where we just printed out a statement. One thing to think about

bindings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1298 58.2 DataType fields . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1298CONTENTS x 58.3 Subtypes tuple is constructed: julia> x = (a=2, b=1+2) (a = 2, b = 3) julia> x[1] 2 julia> x.a 2 The fields of named tuples can be accessed by name using dot syntax (x.a) in addition to the regular indexing that here. You may choose how you wish to handle this exception, whether logging it, return a placeholder value or as in the case below where we just printed out a statement. One thing to think about

bindings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1297 58.2 DataType fields . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1297CONTENTS x 58.3 Subtypes tuple is constructed: julia> x = (a=2, b=1+2) (a = 2, b = 3) julia> x[1] 2 julia> x.a 2 The fields of named tuples can be accessed by name using dot syntax (x.a) in addition to the regular indexing that here. You may choose how you wish to handle this exception, whether logging it, return a placeholder value or as in the case below where we just printed out a statement. One thing to think about