Fluent 6.2.16 Crack 1
Julia Heaslet
In software engineering, a fluent interface is an object-oriented API whose design relies extensively on method chaining. Its goal is to increase code legibility by creating a domain-specific language (DSL). The term was coined in 2005 by Eric Evans and Martin Fowler.[1]
A fluent interface is normally implemented by using method chaining to implement method cascading (in languages that do not natively support cascading), concretely by having each method return the object to which it is attached, often referred to as this or self. Stated more abstractly, a fluent interface relays the instruction context of a subsequent call in method chaining, where generally the context is
Note that a "fluent interface" means more than just method cascading via chaining; it entails designing an interface that reads like a DSL, using other techniques like "nested functions and object scoping".[1]
The term "fluent interface" was coined in late 2005, though this overall style of interface dates to the invention of method cascading in Smalltalk in the 1970s, and numerous examples in the 1980s. A common example is the iostream library in C++, which uses the operators for the message passing, sending multiple data to the same object and allowing "manipulators" for other method calls. Other early examples include the Garnet system (from 1988 in Lisp) and the Amulet system (from 1994 in C++) which used this style for object creation and property assignment.
Fluent interface can also be used to chain a set of method, which operates/shares the same object. Instead of creating a customer class, we can create a data context which can be decorated with fluent interface as follows.
There are many places where fluent APIs can simplify how software is written and help create an API language that helps users be much more productive and comfortable with the API because the return value of a method always provides a context for further actions in that context.
There are many examples of JavaScript libraries that use some variant of this: jQuery probably being the most well known. Typically, fluent builders are used to implement "database queries", for example in the Dynamite client library:
It's possible to create immutable fluent interfaces that utilise copy-on-write semantics. In this variation of the pattern, instead of modifying internal properties and returning a reference to the same object, the object is instead cloned, with properties changed on the cloned object, and that object returned.
In typed languages, using a constructor requiring all parameters will fail at compilation time while the fluent approach will only be able to generate runtime errors, missing all the type-safety checks of modern compilers. It also contradicts the "fail-fast" approach for error protection.
Subclasses in strongly typed languages (C++, Java, C#, etc.) often have to override all methods from their superclass that participate in a fluent interface in order to change their return type. For example:
In a dependently typed language, e.g. Scala, methods can also be explicitly defined as always returning this and thus can be defined only once for subclasses to take advantage of the fluent interface:
A few months ago I attended a workshop with Eric Evans, and hetalked about a certain style of interface which we decided to name afluent interface. It's not a common style, but one we think shouldbe better known. Probably the best way to describe it is by example.
Probably the most important thing to notice about this style isthat the intent is to do something along the lines of an internalDomainSpecificLanguage. Indeed this is why we chose theterm 'fluent' to describe it, in many ways the two terms are synonyms.The API is primarily designed to be readable and to flow. The price ofthis fluency is more effort, both in thinking and in the APIconstruction itself. The simple API of constructor, setter, andaddition methods is much easier to write. Coming up with a nice fluentAPI requires a good bit of thought.
Indeed one of the problems of this little example is that I justknocked it up in a Calgary coffee shop over breakfast. Good fluentAPIs take a while to build. If you want a much more thought outexample of a fluent API take a look at JMock. JMock, like any mockinglibrary, needs to create complex specifications of behavior. Therehave been many mocking libraries built over the last few years,JMock's contains a very nice fluent API which flows verynicely. Here's an example expectation:
So far we've mostly seen fluent APIs to create configurations ofobjects, often involving value objects. I'm not sure if this is adefining characteristic, although I suspect there is something aboutthem appearing in a declarative context. The key test of fluency,for us, is the Domain Specific Language quality. The more the use ofthe API has that language like flow, the more fluent it is.
Building a fluent API like this leads to some unusual API habits.One of the most obvious ones are setters that return a value. (In theorder example with adds an order line to the order and returns theorder.) The common convention in the curly brace world is thatmodifier methods are void, which I like because it follows theprinciple of CommandQuerySeparation. This convention doesget in the way of a fluent interface, so I'm inclined to suspend theconvention for this case.
You should choose your return type based on what you need tocontinue fluent action. JMock makes a big point of moving its typesdepending on what's likely to be needed next. One of the nice benefitsof this style is that method completion (intellisense) helps tell youwhat to type next - rather like a wizard in the IDE. In general I finddynamic languages work better for DSLs since they tend to have a lesscluttered syntax. Using method completion, however, is a plus forstatic languages.
One of the problems of methods in a fluent interface is that theydon't make much sense on their own. Looking at a method browser ofmethod by method documentation doesn't show much sense towith. Indeed sitting there on its own I'd argue thatit's a badly named method that doesn't communicate its intent at allwell. It's only in the context of the fluent action that it showsits strengths. One way around this may be to use builder objectsthat are only used in this context.
One thing that Eric mentioned was that so far he's used, andseen, fluent interfaces mostly around configurations of value objects.Value objects don't have domain-meaningful identity so you can makethem and throw them away easily. So the fluency rides on making newvalues out of old values. In that sense the order example isn't thattypical since it's an entity in the EvansClassification.
I haven't seen a lot of fluent interfaces out there yet, so Iconclude that we don't know much about their strengths andweaknesses. So any exhortations to use them can only be preliminary -however I do think they are ripe for more experimentation.
Update (23 June 2008). Since I wrote this post this term's beenused rather widely, which gives me a nice feeling of tinglygratification. I've refined my ideas about fluent interfaces andinternal DSLs in the book I've been working on. I've also noticed acommon misconception - many people seem to equate fluent interfaceswith Method Chaining. Certainly chaining is a common technique touse with fluent interfaces, but true fluency is much more than that.
To better characterize fluent and nonfluent variants of primary progressive aphasia (PPA). Although investigators have recognized both fluent and nonfluent patients with PPA, the clinical and neuroimaging features of these variants have not been fully defined. We present clinical and neuropsychological data on 47 PPA patients comparing the fluent (n=21) and nonfluent (n=26) subjects. We further compared language features with PET/SPECT data available on 39 of these patients. Compared to the nonfluent PPA patients, those with fluent PPA had greater impairment of confrontational naming and loss of single word comprehension. They also exhibited semantic paraphasic errors and loss of single word comprehension. Patients with nonfluent PPA were more likely to be female, were more often dysarthric, and exhibited phonological speech errors in the absence of semantic errors. No significant differences were seen with regard to left hemisphere abnormalities, suggesting that both variants result from mechanisms that overlap frontal, temporal, and parietal regions. Of the language measures, only semantic paraphasias were strongly localized, in this case to the left temporal lobe. Fluent and nonfluent forms of PPA are clinically distinguishable by letter fluency, single word comprehension, object naming, and types of paraphasic errors. Nevertheless, there is a large amount of overlap between dysfunctional anatomic regions associated with these syndromes.
You can run multiple plugin instances in the same fluent-bit process, for example if you want to push to different Loki servers or route logs into different Loki tenant IDs. To do so, add additional [Output] sections.
Fluent API is a way of implementing object oriented API in a way that it provides readable code. A fluent interface is normally implemented by using method chaining to relay the instruction context of a subsequent call (Wikipedia:Fluent Interface Design). Each line of code does a task oriented operation.
Make sure you practice every day for at least 20 to 30 minutes. This may mean listening to podcasts, watching YouTube videos in fluent American English during your commute, or taking an online course during lunch break.
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