Xreate is an open source general purpose high level programming language designed to write efficient and safe computer programs. Here "high level" has very specific meaning, implying an ability to easily write, read, as well as adapt software to a constantly changing environment or business goals. In this respect, any software product can be evaluated on the basis of the three dimensions: efficiency, safety, and adaptability. Unfortunately, those properties are proved to be largely contradictory, for it is manageable to write either efficient (yet unsafe) or safe (yet impractical) code, but not both. Thus, the ultimate goal of the language is to allow developers to produce code that would have all these properties at the same time. Xreate's design principles allow to adopt any programming technique as long as it does not improve one dimension at the expense of another. To achieve the aforementioned design goals, Xreate employs three distinctive layers: Brute. The lowest layer is called Brute — this is code that is intended to be actually compiled. Code on this level implements actual software functionality. It resembles the usual imperative languages' apparatus and consists of executable instructions such as arithmetic, branching, input/output, etc. Transcend. Brute level alone is not enough to constitute a full-fledged language since code requires various non-executable metadata to express developer's intents, check correctness, validity and perform other types of analyses. In Xreate everything of this sort belongs to a layer called Transcend. Transcend due to its declarative nature is appropriate to do management-type work — it analyzes, oversees and controls brute by guiding compilation process. Everything on this level — logic or transcend facts and rules — is gathered and sent to an external logic solver to make solutions that are brought back in order to guide compilation. Interpretation. There is also Interpretation — the intermediate level resembling dynamically typed languages that is used as a contact point and interpreter between brute and transcend and their respective low level and high level constructs and structures. On a syntactic level, Xreate is a procedural language with extensive use of annotations — arbitrary unconstrained metadata that software developer can attach to different language constructs, variables and code blocks. Annotations are completely invisible for the compiler proper and used by transcend more as a suggestion conveying additional information. "a different language constructs": если подразумевается "конструкции разных языков", тогда лучше "different languages' constructs". Если конструкции языка, в целом, то тогда артикль a не нужен Most severe and hard to resolve problems in software development stem from interaction of different components on different levels. Each individual component often is thoroughly tested and works reliably. But combining them when building end-user software for which purpose complex interaction and extensive IO is enabled usually leads to a range of runtime errors, security vulnerabilities and performance degradation. Thus Xreate places key emphasis on domain-specific component level improvements and joint use of external resources. This aspect is covered in exploitation and containers chapters. Unlike academic languages, Xreate targets safe and reliable usage of effectful computations such as IO covered in virtualization and exploitation chapters, and mutable structures covered in communication.

To demonstrate what Xreate is all about, basic example is given below: name="tests/introduction.cpp: Introduction.Doc_Example_1", lines=15 guard:: iAmVeryFast { div = function(a:: float, b:: float):: float { a / b } } guard:: iAmVerySafe { div = function(a:: float, b:: float):: float { if ( b == (0::float)):: float {0::float} else {a / b} } } test = function:: float; entry; iAmVerySecure { div(10, 5) } Here entry point of the program is a function test recognized so by compiler because of annotation entry in its signature. There are also two functions div called specializations. Each specialization has a guard that defines a condition that has to be met in order to invoke this particular specialization. In the example, specializations of div have iAmVeryFast and iAmVerySafe guards, respectively. Let's say that developer specifies two specializations where the first one is a very fast division implementation, while the second one is a very safe division implementation since it checks division by zero, although it is unacceptably slow due to an extra check instruction. This is a basis of polymorphism — client's code test is able to work with any specialization, and compiler must decide which one to invoke with the only hint it has — annotation iAmVerySecure in the function test's signature. "provides two specializations" - возможно, лучший вариант "designates/assigns/allocates two specializations". Или даже просто specifies/indicates. (PS заменил на specifies) "unbearably slow" - я бы заменил на более нейтральное "too slow". Unbearable - это скорее об ощущениях человека. Или, если под "unbearably" имеется в виду "недопустимо медленный", тогда - unacceptably slow. All annotations (except entry) are custom defined by developer itself. This is when transcend comes into play. By adding a transcend rule as shown below it is possible to associate annotation iAmVerySecure with invocation of specialization guarded by iAmVerySafe: name="tests/introduction.cpp: Introduction.Doc_Example_1", lines=15 dfa_callguard(SiteInv, iAmVerySafe):- dfa_callfn(SiteInv, div); SiteInv = s(_, _, ScopeInv); cfa_parent(ScopeInv, function(FnInv)); bind_func(FnInv, iAmVerySecure). Transcend rules are written in ASP syntax — common syntax to write logic programs. This particular rule reads that for any function annotated with iAmVerySecure, certain specialization iAmVerySafe is chosen for div invocation. In this example an appropriate specialization is statically resolved, so the other specialization isn't even compiled. the, потому что их всего две. By providing custom rules it is possible to implement any polymorphism strategy, be it performed statically or dynamically. The example demonstrates basic workflow: transcend gathers available information about a program such as annotations and using custom rules makes a decision to guide compilation process, particularly by selecting appropriate specializations as in the above example.

Major dependencies: gcc 7 llvm 5, clang 5 boost 1.66 coco clingo Building tested on OpenSuse Leap 15. Please change commands accordingly if using other distributions. Pull sources directly from repository: git clone --recursive https://pgess@bitbucket.org/pgess/xreate.git Enter into the source directory and run the following script to prepare building environment. Script will install the required system packages as well as Coco and Clingo from sources: "Enter into source directory" - тут перед directory явно нужен артикль. Гугл говорит, что определенный - the Carefully inspect scripts before run On OpenSuse Leap 15: ./installation/prepare-opensuse-leap15 That was one time operation to prepare environment. After that enter into build directory and start actual tests building: "build directory": здесь ты все-таки вначале указываешь имя объекта (build), и лишь потом родовое название (directory) cd build make After successful build you can run xreate tests: cd .. ./build/tests/xreate-tests Please pay attention that the working directory should be the repository root For consequent rebuilds after updates etc invoke cmake as follows: #working dir build cmake -DCMAKE_BUILD_TYPE=Debug \ -DBUILD_XREATE_TESTS=1 \ -DCOCO_EXECUTABLE=<FILE> \ -DCLINGO_PATH=<DIR> \ -DCOCO_FRAMES_PATH=../vendors/coco/generator/ \ -DCMAKE_CXX_COMPILER=g++ ../cpp make Cmake's selected parameters: BUILD_XREATE_TESTS Determines whether to build tests COCO_EXECUTABLE Full filename of Coco executable CLINGO_PATH Installed Clingo directory "Directory of Clingo installation": может, with Clingo installation? (это если речь идет о папке, где хранятся инсталляционные файлы) Если наоборот, куда будет устанавливаться - тогда Directory for installing Clingo. Оригинальный вариант ("of Clingo installation") немного сбивает с толку.