I am c++/C expert, I like because it is easier than C++ and more powerful and flexible than C with Golang , you would not need consider create/destroy/monitor pthread , crazy pointer is not problem also . as far as I know , most of golanger is original user of C/C++
在 2018年3月3日星期六 UTC+8上午5:29:45,dorival...@gmail.com写道: > > Hi, I could be wrong (please correct me ;-), but here you are what I think > about Go: > > INTRODUCTION > Computers and software were initially developed for scientific computing; > e.g., ALGOL and FORTRAN from the 1950s! Therefore, several computer > languages and libraries have been invented and are used in scientific > computing to date. Nonetheless, when programming a new scientific > simulation, the question about computational efficiency versus ease-of-use > remains open. Here, we aim to shed light on a suitable answer to this > question---TL;DR use Go and Gosl! > > One would say that scripting (interpreted) languages might provide the > convenient platform for computations as long as care is taken to send > intensive tasks to functions pre-compiled with high-performance languages. > This strategy fails to create an easy-to-use environment because the > programmer needs to think when and where those tasks should go. Considering > that this kind of decision is essential for performance, we argue that > scripting language is not the best solution. Furthermore, we argue that > scripting is the worst tool for teaching new programmers in scientific > computing. > > We argue that only experts should use scripting languages (scripts) for > computer programming because beginners cannot understand how dangerous the > flexibility of scripts can be. For example, the assignment of variables > with the same name to different types is often a cause of misunderstandings > and failures. To make this problem even worse, failures due to wrong types > are not captured at runtime---certainly not at compilation time (there is > no compilation time in scripts). In other words, the interpreter is too > permissive. The scientist, if aware (rarely the case with students), will > investigate the numerical output and, after much work, will find the source > of the error. Therefore, this situation is not ideal. To exemplify, the > following is allowed in Python (or Julia---similar syntax): > > ``` > a = 1.0 > a = "a" # OK in Python or Julia > ``` > > In the following code, Go will detect the error with a message such as > `./test.go:5: cannot use "a" (type string) as type float64 in assignment`: > > ``` > package main > func main() { > a := 1.0 > a = "a" // not accepted in Go > } > ``` > > The problem propagates in scripting languages when developing > objected-oriented code. For example, a member data of a class can be > entirely modified by `anyone`, `anywhere` in Python! This issue completely > defeats the purpose of encapsulation in OOP. > > In summary, scripting (e.g., Python) and alike (e.g., Julia, Matlab) > languages are excellent for the expert programmer only who can understand > what is going on. However, they are very misleading to the beginner. In > other words, the strictness of compiled languages DOES help to learn > computer programming. Furthermore, the tools for working with compiled > language often take advantage of well-defined types. The shift towards type > declaration is so apparent that new languages and strategies are being > invented to overcome these issues. For example, TypeScript and Javascript > (ES6) combined with FlowType have been recently developed and have a fast > adoption among web developers. It seems that no new large project will use > non-typed Javascript code. > > GO LANGUAGE > Go is a modern programming language created by Google engineers in 2007, > including Robert Griesemer, Rob Pike, and Ken Thompson. The language was > later made public as open source in 2009. Go has since grown exponentially > attracting a large number of co-developers and users. The primary goal > leading to the introduction of yet a new language was the combination of > efficiency (like C/C++) with ease of development (like Python). There are > other several innovations and advantages in Go when compared with > mainstream languages such as C/C++/C#/Java/Python/Ruby/Lua. > Also, Go automatically detects Fortran and C files which helps taking > advantage of good existing code. > > The vocabulary in Go is quite small compared to other languages, making > easy to have an overview of the syntax and available commands. Go avoids > complexities such as generics (aka templates) usually available in other > languages (e.g., C++). Go also tries to avoid unnecessary complexity by not > taking `in the language` advanced OOP concepts such as polymorphism, > multiple inheritances, and others. Moreover, Go is somewhat pragmatic in > the sense that, if an operation can be made much more straightforward, > although slightly orthogonal to the central paradigm, this operation will > be carefully defined and adopted in the language specification. These > features, thanks to the unquestionable expertise of the core developers, > made Go an enjoyable language to work with. > > One limitation of some other languages is code organization and package > development. For example, C/C++ require the use of `#ifndef`, `#define`, > `#endif`, or `#pragma once` everywhere to prevent code being included more > than once. In fact, it is frustrating at times to find how to deal with > this situation in C/C++, noting that the developer has to worry about what > code goes in the header (.h, .hpp) or in the (.c, .cpp) files. Moreover, > the cyclic nature of `imports` using C/C++ can be a nightmare. > > In Python, the organization of packages sometimes lead to situations where > the naming becomes very confusing. For example, we cite the case with > matplotlib.pyplot or pylab or other packages called mypackage.mypackage > that we find around. As another example, in Julia, module definition is > messy, because the user (programmer) has to decide among the files to be > included versus module definition. In summary, package definition is not > simple in Python or Julia. > > On the other hand, Go was designed from the beginning to be multi-modular, > prevent cyclic dependency, and made package definition simple. In Go, the > solution is based on how the directories are organized. For example, each > directory is a package, and all files in the same directory belong to that > package. When importing code from other packages, the full path (like URL) > of that package is used. There is no need for `header` files in Go! > Moreover, the coding of one feature can span multiple files in the same > directory. Go comes with a set of tools to build applications and even > download third-party code. > > Go also has a strict convention for code formatting. In other words, there > is only one way to format your code in Go---using braces starting at the > end of the line with the `standard` indentation. In this way, a true > `standard` exists for Go codes which makes sharing straightforward and > quite pleasant; e.g., no one argues about the positioning of braces > anymore! Moreover, the strict code convention and specification in Go > largely facilitates the development of auxiliary programming tools to > process code. For instance, the import field in source code can be > automatized as is done with the excellent goimports tool. Many other tools > (e.g., vet, lint) take advantage of Go conciseness. > > Because files and directories in Go follow a well-defined specification, > it is very easy (and fast) to find definitions, code lines, files, and > packages (libraries) in Go projects. The compiler in Go benefits from this > organization and indeed helps with Go being very fast to compile code---you > can run Go code as if it was a scripting language! Furthermore, the > excellent specification and organization in Go helped with the creation of > many other tools to assist in Go code development. For instance, we > mention the `goimports` and `gorename` that automatically import all > dependencies as you type and rename a variable in all code derived from a > particular library. > > Furthermore, also thanks in part to how well the Go specification and > conciseness were invented, there are several other useful and fast commands > for handling Go code. For instance, we mention the commands `go run,` `go > build`, `go install` and `go get` that perform the operations of running > the code, building the code, installing the code and downloading (and > compiling) external dependencies automatically. > > One particular innovation in Go is the concept of concurrency that can > lead to easy-to-write parallel algorithms. Also, Go is a garbage-collected > language that makes easier the code development with fewer worries about > dangling pointers. Go is in part compiled in Go language and has a > reasonably comprehensive standard library, including tools for sorting, > templating, encodings, cryptography, compression algorithms, mathematical > functions (e.g., for complex numbers), image tools, and even web servers. > Furthermore, Go uses the concept of unit tests very well and even includes > tools to assist in benchmarking. Also, Go comes with tools to prepare > examples and to automate the documentation---there is no need for Doxygen! > > The Go language syntax resembles that of C/C++/Java (C-class) but has > significant differences. One fundamental difference is the way variables > are declared. The type definition comes after the variable name. This > difference seems strange at first to C-class programmers, but it makes > sense. In fact, it makes reading easy, where one would read `variable and > anotherVariable` are `float64` in `variable, anotherVariable > float64`---there is no need to type float64 twice (or ten times...). The > syntax is particularly convenient when declaring multiple function > arguments. > > Go uses curly braces to define scope but has a strict rule regarding where > the braces can be put and how to deal with indentation. This approach makes > the code consistent and easy for collaborations. Also, with the help of > the tools called `goimports` and `gofmt`, the workflow is straightforward. > Go allows some constructions similar to the `range` command in Python and > does not require the use of parentheses in repetition commands as in > C-class. > > There is only one repetition command in Go: the `for` keyword. Compared to > C-class languages, the syntax of the `switch` command is simpler and more > powerful. Because of that, the programmer is induced (positively) to use > `switch` over `if` when there is more than one decision branch. > > Go code can be directly executed as in: `go run hello.go`. The code could > be built first with `go build hello.go' and executed (Linux) with > `./hello`. But this last approach is only necessary when deploying the > final application. In fact, Go can be used as scripting (using `go run` > like `python`). > > Variables are defined in two ways: the first one requires the command > `var` and the second one uses the assignment operator `:=` which > automatically understands the data type. Another great advantage of Go when > compared to many other languages is the standardized auto-initialization of > all variables to their `zero` default value. For instance, numeric > variables declared with `var` are always zero and strings are always empty. > This feature can be exploited with advantage by the programmer who may > consider variable names such that everything starts zeroed already. For > instance, instead of creating a `silent` variable that needs to be set to > `true` all the time, it's more convenient to use a `verbose` variable that > is always `false` already. > > One type that is extensively used in Go is the `slice` of integers or real > numbers represented by float point numbers (64-bit version; aka `double` in > C-class). Slices in Go are a view to an internal sequence of values; i.e., > slices record the start and end positions in memory. Therefore, slices can > be passed into functions with minimal overhead. There is hence no need for > constantly worrying about `by reference` or `by value`. Pointers can also > be used in Go. We use pointers whenever a user-defined structure is to be > modified by the called function. In Go, the slice notation `S[s:E]` means a > view to array `S` starting at `s` and ending at `E-1`, inclusive. > > In conclusion, code written in Go is beautiful, concise and with a very > clear logic. > > -- You received this message because you are subscribed to the Google Groups "golang-nuts" group. To unsubscribe from this group and stop receiving emails from it, send an email to golang-nuts+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.