In this portion of our guide to computer programming languages, we'll focus on Ciao, a general-purpose programming language in the Prolog family.
While Ciao first appeared forty years ago, in 1984, it continues to be under active development and maintenance on GitHub, and is available under the GPL and LGPL licenses.
Among its key features is constraint logic programming. Ciao embraces the core strengths of Prolog, supporting the ISO-Prolog standard, allowing programmers to express complex relationships and constraints declaratively.
Ciao extends Prolog to offer meta-programming, higher-order functions, concurrency, and other features, lending the flexibility to tackle diverse problem domains.
Ciao's syntax and semantics can be extended further by user-defined packages that enhance expressiveness and allow seamless interaction with foreign code.
Ciao builds upon the logic-based simple kernel, designed to be portable, extensible, and modular.
Ciao facilitates large-scale development through modularization, allowing for the organization of code into reusable modules and bundles. Ciao unifies static and dynamic verification using assertions, which ensures robustness and correctness.
Among the design goals of Ciao were declarative power (leveraging Prolog's elegance for logical reasoning, practicality (bridging the gap between theory and real-world applications), extensibility (allowing users to define their own language extensions), and modularity (encouraging well-structured, maintainable code).
Although Ciao's greatest influences were from Prolog, it also incorporates ideas from other languages, like Constraint Handling Rules (CHR) and functional programming.
Ciao's strengths include its declarative nature, which simplifies complex problems. User packages and modular design promote flexibility, and its seamless integration with foreign code is an additional strength.
Prolog's unique paradigm, carried over into Ciao, can be challenging for newcomers, and its adoption is more specialized due to its focus on logical programming.
Ciao's applications include artificial intelligence, software verification, and web development. Ciao can run natively or even in a browser without installation.
Ciao extends Prolog with additional features, making it more versatile, and it shares some similarities with CHR, particularly in constraint handling.
Ciao stands at the intersection of logic, pragmatism, and extensibility.
Recommended Resources
An Overview of Ciao and its Design Philosophy
Published on arXiv, an open-access repository of electronic preprints and post-prints, known as e-prints, which serves as a platform for sharing scholarly articles in various fields, this paper provides insights into the Ciao multiparadigm programming system. Ciao is a modern Prolog implementation that builds upon a logic-based simple kernel. Its design goals, key features, and programming environment are discussed, illustrating its design philosophy.
https://arxiv.org/abs/1102.5497
Cambridge: An Overview of Ciao and its Design Philosophy
Published in the journal "Theory and Practice of Logic Programming," and hosted on the website of Cambridge University Press, the paper discusses the Ciao programming system, a multiparadigm language that goes beyond traditional logic programming, particularly Prolog. The key aspects of Ciao (multiparadigm approach, extensibility, programming environment, and design philosophy) are outlined, along with an informal overview, highlighting its design philosophy.
https://www.cambridge.org/core/journals/theory-and-practice-of-logic-programming/article/abs/an-overview-of-ciao-and-its-design-philosophy/5CEA99C1E160B3D8EBE50AB9A124D969
Licensed by the GNU General Public License and the GNU Lesser General Public License, Ciao is a general-purpose programming language, developed in 1984, that provides a full Prolog system, supporting ISO-Prolog, declarative subsets and extensions of Prolog. The Ciao Project is discussed, with development notes, source code patches, and bug reports, as well as documentation that includes a free PDF book on the language, reference manuals, and a catalog of Ciao bundles.
https://ciao-lang.org/
Hosted on the official Ciao programming language website, this is a web-based platform designed to explore and experiment with Ciao, a modern Prolog system, which was specifically crafted for writing safe, correct, and efficient Prolog programs, providing a rich set of features for developers. The Ciao system is compiled into WebAssembly, allowing it to run fully inside of a web browser. The playground serves as an interactive learning environment, allowing experimenting with code snippets.
https://ciao-lang.org/playground/
GitHub: The Ciao Programming Language
Ciao is a modern Prolog implementation that builds up from a logic-based simple kernel designed to be portable, extensible, and modular, and a general-purpose, multi-paradigm programming language in the Prolog family. Its official GitHub repository has several interconnected repositories, including the source code for the language, the Ciao playground, a preprocessor, documentation, and several other tools and utilities designed to work with Ciao. Contributor profiles are included.
https://github.com/ciao-lang
