Play Video
1
Type-ZERO - All Systems Nominal (MechWarrior Online Tribute)
Type-ZERO - All Systems Nominal (MechWarrior Online Tribute)
::2013/01/02::
Play Video
2
Scala
Scala's Type System: a tutorial
::2012/04/01::
Play Video
3
All Systems Nominal: Episode #5 - Confrontation
All Systems Nominal: Episode #5 - Confrontation
::2013/07/19::
Play Video
4
All Systems Nominal: Episode #6 - Retroactive
All Systems Nominal: Episode #6 - Retroactive
::2014/11/04::
Play Video
5
Data Types C# - common language runtime types, nominal storage allocation, and value range
Data Types C# - common language runtime types, nominal storage allocation, and value range
::2014/09/26::
Play Video
6
Systems Nominal (Anything But)
Systems Nominal (Anything But)
::2014/12/23::
Play Video
7
All Systems Nominal: Episode #1 - Watchful Cicada
All Systems Nominal: Episode #1 - Watchful Cicada
::2013/02/01::
Play Video
8
Systems Nominal | Nerd³
Systems Nominal | Nerd³'s Early Christmas Present
::2014/12/24::
Play Video
9
[DOWNLOAD] MW3 Reactor online, sensors online, weapons online, all systems nominal
[DOWNLOAD] MW3 Reactor online, sensors online, weapons online, all systems nominal
::2012/03/10::
Play Video
10
All Systems Nominal: Episode #3 - Equilibrium
All Systems Nominal: Episode #3 - Equilibrium
::2013/03/31::
Play Video
11
All Systems Nominal: Episode #2 - Fright Night
All Systems Nominal: Episode #2 - Fright Night
::2013/02/23::
Play Video
12
All Systems Nominal
All Systems Nominal
::2012/06/20::
Play Video
13
Top 30 Richest Countries in Africa by GDP Nominal
Top 30 Richest Countries in Africa by GDP Nominal
::2014/05/16::
Play Video
14
APC Smart-UPS SC620 4-Outlet 620VA 390W UPS System
APC Smart-UPS SC620 4-Outlet 620VA 390W UPS System
::2014/08/26::
Play Video
15
Trust Gxt 38 2.1 Speaker System
Trust Gxt 38 2.1 Speaker System
::2015/01/31::
Play Video
16
[MWO] All Systems Nominal
[MWO] All Systems Nominal
::2012/11/09::
Play Video
17
AMADA/WASINO G-05 2-AXIS CNC HIGH SPEED GANG TYPE CHUCKER WITH GANTRY LOADING SYSTEM
AMADA/WASINO G-05 2-AXIS CNC HIGH SPEED GANG TYPE CHUCKER WITH GANTRY LOADING SYSTEM
::2014/11/05::
Play Video
18
Nominal Ledger
Nominal Ledger
::2012/11/09::
Play Video
19
systems nominal new hack 2015
systems nominal new hack 2015
::2014/12/23::
Play Video
20
HI-TEX Active spekers, Hornsonic
HI-TEX Active spekers, Hornsonic
::2011/04/17::
Play Video
21
PylePro PDWM3400 Premier Series UHF Microphone System with 2 Body-Pack Transmitters 2 Headsets
PylePro PDWM3400 Premier Series UHF Microphone System with 2 Body-Pack Transmitters 2 Headsets
::2015/01/26::
Play Video
22
Logitech X-140 Speakers Unboxing & Inside Look
Logitech X-140 Speakers Unboxing & Inside Look
::2009/09/25::
Play Video
23
Golden Rules of Accounting,how to understand the concepts of Real,Personal and Nominal account rules
Golden Rules of Accounting,how to understand the concepts of Real,Personal and Nominal account rules
::2013/09/05::
Play Video
24
Logitech Z 506 Speaker System
Logitech Z 506 Speaker System
::2012/01/28::
Play Video
25
DIATONE DS-77Z
DIATONE DS-77Z
::2014/06/12::
Play Video
26
APC SU1400rmi2u UPS used as a 24VDC to 240VAC inverter
APC SU1400rmi2u UPS used as a 24VDC to 240VAC inverter
::2014/02/07::
Play Video
27
Jamo S-35-HCS-BLK 5.0 Home Cinema System - Black
Jamo S-35-HCS-BLK 5.0 Home Cinema System - Black
::2014/12/11::
Play Video
28
Assembleon (Philips) Gem Series Topaz Placement System
Assembleon (Philips) Gem Series Topaz Placement System
::2011/07/18::
Play Video
29
How to Select the Right FRAM (F-RAM) for your Applications
How to Select the Right FRAM (F-RAM) for your Applications
::2013/10/21::
Play Video
30
How to Use SPSS: Oraganizing,Coding and Entering Data for Non-Parametric Data Analysis
How to Use SPSS: Oraganizing,Coding and Entering Data for Non-Parametric Data Analysis
::2013/08/28::
Play Video
31
Creative T6160 5.1 Unboxing
Creative T6160 5.1 Unboxing
::2011/01/14::
Play Video
32
How to tell if your Samsung Galaxy S3 CPU is fast, nominal or slow.
How to tell if your Samsung Galaxy S3 CPU is fast, nominal or slow.
::2013/02/22::
Play Video
33
Learn Modern Standard Arabic (structure - Nominal sentence) Fosha Lesson 9 of 11
Learn Modern Standard Arabic (structure - Nominal sentence) Fosha Lesson 9 of 11
::2013/10/03::
Play Video
34
APC Smart-UPS RM SMT1500RM2U 1000W/1440VA 2U Rackmount LCD UPS System Quick Review
APC Smart-UPS RM SMT1500RM2U 1000W/1440VA 2U Rackmount LCD UPS System Quick Review
::2015/02/05::
Play Video
35
Alpine 117, Alpine SWR-1242D (600 Watt Nominal), Dls Mad11 (750 Watt-2Om)
Alpine 117, Alpine SWR-1242D (600 Watt Nominal), Dls Mad11 (750 Watt-2Om)
::2014/11/19::
Play Video
36
Video review "MyTinySun" HEAD 1000 PRO Lighting System.
Video review "MyTinySun" HEAD 1000 PRO Lighting System.
::2013/11/19::
Play Video
37
Multi strand system.avi
Multi strand system.avi
::2012/03/30::
Play Video
38
NEW Subaru WRX STI 2015 Impreza official video
NEW Subaru WRX STI 2015 Impreza official video
::2014/01/14::
Play Video
39
Changing Battery - Razor MX650 Dirt Rocket
Changing Battery - Razor MX650 Dirt Rocket
::2014/12/12::
Play Video
40
JBL EON 210P Portable PA System @ Namm 2012 with DJkit.tv
JBL EON 210P Portable PA System @ Namm 2012 with DJkit.tv
::2012/01/31::
Play Video
41
HOW Mad Mimi: Gaining & Keeping Clients using RFPs with Janine Gregor
HOW Mad Mimi: Gaining & Keeping Clients using RFPs with Janine Gregor
::2015/01/07::
Play Video
42
APC Smart-UPS SMX1000 X 1000VA Rack/Tower LCD 120V UPS System Quick Review
APC Smart-UPS SMX1000 X 1000VA Rack/Tower LCD 120V UPS System Quick Review
::2015/01/28::
Play Video
43
Jamo 360 S 25 HCS 5.0 Home Cinema System
Jamo 360 S 25 HCS 5.0 Home Cinema System
::2015/01/25::
Play Video
44
Razor MX650 (+LiFePO4) First Winter Ride - way
Razor MX650 (+LiFePO4) First Winter Ride - way 'Hobby marketplace - Preobrazhenskaya Ploschad'
::2014/12/14::
Play Video
45
SELF-EXPANDING NITINOL STENT "JAGUAR" with delivery system
SELF-EXPANDING NITINOL STENT "JAGUAR" with delivery system
::2014/02/28::
Play Video
46
PROpak Portable Foam System
PROpak Portable Foam System
::2014/05/16::
Play Video
47
APC Smart-UPS RM SMT1000RM2U 700W/1000VA 120V 2U Rackmount LCD UPS System
APC Smart-UPS RM SMT1000RM2U 700W/1000VA 120V 2U Rackmount LCD UPS System
::2014/08/30::
Play Video
48
KRK KNS 8400 Unboxing
KRK KNS 8400 Unboxing
::2012/05/18::
Play Video
49
Kef Coda 8 (serie melhorada)
Kef Coda 8 (serie melhorada)
::2012/07/31::
Play Video
50
AEMC® - PEL App For Android™
AEMC® - PEL App For Android™
::2014/08/08::
NEXT >>
RESULTS [51 .. 101]
From Wikipedia, the free encyclopedia
  (Redirected from Nominative type system)
Jump to: navigation, search

In computer science, a nominal or nominative type system (or name-based type system) is a major class of type system, in which compatibility and equivalence of data types is determined by explicit declarations and/or the name of the types. Nominal systems are used to determine if types are equivalent, as well as if a type is a subtype of another. It contrasts with structural systems, where comparisons are based on the structure of the types in question and do not require explicit declarations.

Nominal typing[edit]

Nominal typing means that two variables are type-compatible if and only if their declarations name the same type. For example, in C++, two struct types with different names are never considered compatible, even if they have identical field declarations.

However, C++ also allows a typedef declaration, which introduces an alias for an existing type. These are merely syntactical and do not differentiate the type from its alias for the purpose of type checking. This feature, present in many languages, can result in a loss of type safety when (for example) the same primitive integer type is used in two semantically distinct ways. Haskell provides the C-style syntactic alias, as well as a declaration that does introduce a new, distinct type, isomorphic to an existing type.

Nominal subtyping[edit]

In a similar fashion, nominal subtyping means that one type is a subtype of another if and only if it is explicitly declared to be so in its definition. Nominally-typed languages typically enforce the requirement that declared subtypes be structurally compatible (though Eiffel allows non-compatible subtypes to be declared). However, subtypes which are structurally compatible "by accident", but not declared as subtypes, are not considered to be subtypes.

C++, C#, Java, Objective-C, Delphi and Swift all primarily use both nominal typing and nominal subtyping.

Some nominally-subtyped languages, such as Java and C#, allow classes to be declared final (or sealed in C# terminology), indicating that no further subtyping is permitted.

Comparison[edit]

Nominal typing is useful at preventing accidental type equivalence, and is considered[by whom?] to have better type-safety than structural typing. The cost is a reduced flexibility, as, for example, nominal typing does not allow new super-types to be created without modification of the existing subtypes.

See also[edit]

Notes[edit]

References[edit]

External links[edit]

Wikipedia content is licensed under the GFDL License
Powered by YouTube
MASHPEDIA
LEGAL
  • Mashpedia © 2015