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Qore (programming language)

Qore (programming language) is a computer science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Qore (programming language) rather than just read about it. In short: Qore is an interpreted, high-level, general-purpose, garbage collected dynamic programming language, featuring support for code embedding and sandboxing with optional strong typing and a focus on fundamental support for multithreading and SMP scalability. Qore is unique because it is an interpreted scripting language with fundamental support for multithreading (meaning more than one part of the same code can run at…

Key takeaways

  • Qore (programming language) belongs to computer science; place it in that map before memorising details.
  • Learn the definition first, then one example that makes the definition concrete.
  • Connect Qore (programming language) to a quantity you can measure, compute or draw — that is where exam questions come from.
  • Reproduce the core statement of Qore (programming language) from memory before moving on to harder problems.

Reference excerpt

Qore is an interpreted, high-level, general-purpose, garbage collected dynamic programming language, featuring support for code embedding and sandboxing with optional strong typing and a focus on fundamental support for multithreading and SMP scalability. Qore is unique because it is an interpreted scripting language with fundamental support for multithreading (meaning more than one part of the same code can run at the same time), and additionally because it features automatic memory management (meaning programmers do not have to allocate and free memory explicitly) while also supporting the RAII idiom with destructors for scope-based resource management and exception-safe programming. This is due to Qore's unique prompt collection implementation for garbage collection.

Qore Scripts Qore scripts typically have the following extensions:

.q: for Qore scripts .qm: for Qore user modules .qtest: for Qore test scripts Executable Qore scripts on Unix-like operating systems will typically start with a hashbang to specify the filename of the interpreter as follows:

#!/usr/bin/env qore

Syntax Qore syntax is similar to and inspired from the following programming languages:

Perl: without %new-style, Qore's syntax is highly similar to Perl; the foreach statement, splice, push, pop, chomp operators, Perl5-compatible regular expressions, and more Java: with %new-style, Qore code looks more similar to Java; the synchronized keyword, the instanceof operator, object and class implementation C++: multiple inheritance, exception handling, static methods, abstract methods D: the on_exit, on_success, and on_error statements provide exception-aware functionality similar to D's scope(exit), scope(failure), allowing exception-aware cleanup code to be placed next to the code requiring cleanup Haskell: the map, foldl, foldr, and select operators with lazy evaluation of functional and list operators and statements

Data Types Basic types include: boolean, string, integer, float, date, binary, list, hash (associative arrays), and object, as well as code code for code used as a data type. Complex types are also supported such as hash<string, bool>, list<string>, reference<list<string>> as well as type-safe hashes Archived 2017-09-30 at the Wayback Machine.

Multithreading Despite being an interpreted language, Qore was designed to support multithreading as a fundamental design principle. All elements of Qore are thread-safe, and the language in general has been designed with SMP scalability in mind. Because all elements of the language were designed to support multithreading, Qore programs and scripts do not have to limit themselves to a subset of Qore's functionality, which is also why there is no Global interpreter lock in Qore. Threading functionality in Qore is provided by the operating system's POSIX threads library.

Garbage Collection Qore features a unique garbage collection approach called prompt collection that allows destructors to be run immediately when objects go out of scope, even if they have recursive references back to themselves. This allows for Qore to support the RAII idiom and also perform garbage collected automatic memory management.

Support for Code Embedding and Sandboxing Qore was designed to support embedding and sandboxing logic in applications; this also applies to applications written in Qore as well as applications using the Qore library's public C++ API. By using the Program class which represents a logic container with sandboxing controls, discrete objects can be created and destroyed at runtime containing embedded code to extend or modify the behavior of your application in user-defined ways.

Runtime Library Qore's standard runtime library supports data mapping, APIs for communicating with databases (including high-level APIs for SQL operations, schema management, and DBA actions), client APIs and server infrastructure implementations for many protocols including HTTP, REST (with REST schema validation/code generation including Swagger support), client/server SOAP support (including code and message generation), WebSocket, RPC protocols, generic connector APIs Archived 2017-09-30 at the Wayback Machine, generic data mapping APIs Archived 2017-09-30 at the Wayback Machine, and many file format and file- and data-exchange protocols and more.

Testing Qore supports testing through the QUnit module Archived 2018-08-19 at the Wayback Machine which facilitates automated testing and Continuous integration processes for code written in Qore.

Availability Qore's Git (software) repository is hosted on GitHub. Binary packages are available as RPM s, in MacPorts and in FreeBSD Ports as well as for other operating systems, including Microsoft Windows; see General Source and Download Info on the Qore wiki for more information.

References

External links Official website Qore Wiki (github.com) Qore for the Perl Programmer (houston.pm.org) openSUSE (software.opensuse.org) NetBSD (ftp.netbsd.org) FreeBSD (portsmon.freebsd.org)

Worked examples

Example 1 — a first encounter with Qore (programming language)

Start with the simplest possible case. Write down what Qore (programming language) claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In computer science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Qore (programming language) before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Qore (programming language) ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Qore (programming language)

In research
Qore (programming language) appears in computer science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry
Engineering practice reuses Qore (programming language) in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom
Qore (programming language) is common in secondary-school and first-year university syllabi. It links to neighbouring topics American inventions, Cross-platform software, Dynamic programming languages, so understanding it makes those chapters shorter.
In everyday life
Look for Qore (programming language) outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Qore (programming language) in 20 minutes

  1. Read the reference excerpt below once, without taking notes.
  2. Close the page and write down what Qore (programming language) means in your own words.
  3. Compare your version with the excerpt and mark what you missed.
  4. Work through the three examples above with pen and paper.
  5. Explain Qore (programming language) out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Qore (programming language) in simple terms?

Qore is an interpreted, high-level, general-purpose, garbage collected dynamic programming language, featuring support for code embedding and sandboxing with optional strong typing and a focus on fundamental support for multithreading and SMP scalability. Qore is unique because it is an interpreted…

Why does Qore (programming language) matter?

Because it connects several computer science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Qore (programming language)?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Qore (programming language).

Tags

  • American inventions
  • Cross-platform software
  • Dynamic programming languages
  • Dynamically typed programming languages
  • Free and open source interpreters
  • Free software programmed in C++
  • High-level programming languages
  • Object-oriented programming languages
  • Procedural programming languages
  • Programming languages
  • Scripting languages
  • Software using the GNU General Public License

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