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Simple .NET/ASP.NET PDF document editor web control SDKMaintainability is concerned with the evolution of your system over time. It s highly unusual to ship an application and have all business stakeholders and users simultaneously proclaim Yes! Yes! This is exactly what we needed! It does the job perfectly! It s more likely that they ll start requesting changes right away. Sometimes they ll wait a day while your team recovers from pulling an all-nighter to get the thing working in production in the first place, but when they do make requests, what type of changes to the system can you expect Your initial requirements may be quite a bit more ambitious than what you ve committed to ship on the application s first iteration. Office was not built in a day. However, knowing the requirements that will be present in future iterations can be of great benefit during the architectural design phase, as you can take some of these features into account in the solution. how to install barcode font in excel 2010, free barcode add in for excel 2007, how to put barcode in excel 2010, how to add barcode in excel 2007, barcode data entry excel, how to create barcodes in excel 2010 free, active barcode excel 2003, barcode in excel 2003, convert text to barcode in excel 2016, download barcode font for excel 2010,let lookupName nm (dict : Dictionary<string,string>) = let mutable res = "" let foundIt = dict.TryGetValue(nm, &res) if foundIt then res else failwithf "Didn t find %s" nm At the time of this writing, the previous code gives a warning in F# since the use of the address-of operator & may lead to unverifiable or even invalid .NET code. The use of a reference cell can be cleaner. For example: > let res = ref "";; val res: string ref > capitals.TryGetValue("Australia", res);; val it: bool = false > capitals.TryGetValue("USA", res);; val it: bool = true > res;; val it: string ref = { contents = "Washington" } Finally, here is the technique where you simply don t pass the final parameter, and instead the result is returned as part of a tuple: > capitals.TryGetValue("Australia");; val it: bool * string = (false, null) > capitals.TryGetValue("USA");; val it: bool * string = (true, "Washington") Note the value returned in the second element of the tuple may be null if the lookup failed when this technique is used. null values are discussed in the section Working with null Values at the end of this chapter. Note All SQL submitted from JDBC is dynamic. This is clear from the fact that to find a syntax error in You can use dictionaries with compound keys such as tuple keys of type (int * int). If necessary, you can specify the hash function used for these values when creating the instance of the dictionary. The default is to use generic hashing, also called structural hashing, a topic covered in more detail in 8. If you want to indicate this explicitly, you do so by specifying Microsoft.FSharp.Collections.HashIdentity.Structural when creating the collection instance. In some cases, this can also lead to performance improvements because the F# compiler often generates a hashing function appropriate for the compound type. Here is an example where we use a dictionary with a compound key type to represent sparse maps: The application may also have a subset of features that are so volatile that it may be worth the investment to create some user interfaces that are entirely polymorphic in their behavior, and create a tool for end users (or power users) to control how this portion of the interface gets rendered There may even be a vendor-supplied tool that meets these requirements for you Content management systems and Web portal packages are just a couple of examples of generalized solutions that let qualified users affect the application at a higher level of abstraction than cranking out and compiling code Your application may have requirements that can be met by network or application administrators via configuration files or Microsoft Management Console (MMC) snap-ins These are tasks technical people need to perform, but they don t necessarily require a developer to change code that then needs to be compiled and shipped. the SQL string, you need to run the program. The only way to take advantage of static SQL from JDBC is to use PL/SQL and invoke it from the CallableStatement interface. > open System.Collections.Generic;; > open Microsoft.FSharp.Collections;; > let sparseMap = new Dictionary<(int * int), float>();; val sparseMap : Dictionary <string, string list> > sparseMap.[(0,2)] <- 4.0;; val it : unit = () > sparseMap.[(1021,1847)] <- 9.0;; val it : unit = () > sparseMap.Keys;; val it : Dictionary.KeyCollection<(int * int),float>
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