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Explang Goals and Features

Focus on support for Programming in the Small, friendliness to casual users of the language

  • Dynamic typing, implicit conversions to Boolean and numeric values when required.
  • Dynamic variables: allows for passing values as variables in the context and defining user functions without arguments.
  • Lisp2 language: different namespaces for variables and functions, so there is no potential conflict between user-defined variables and built-in functions.
  • Batteries included: contains rich set of utility functions for operating on collections, regexp and globbing support, etc.
  • Support for both imperative and functional style programming.
  • Has a rich set of features for defining function arguments (keyword args, rest args, optional args, etc) instead of functions overloading.
  • Documentation mechanism for user functions and builtins.

Pluggable parsers for language syntax

Explang comes with two parsers for LISP like languages: - lisp - recursive parser that a sub-set of Common Lisp parser features. - sexp - simple S-exp parser that is written imperatively (no depth limit because of JVM stack).

There is a parser with a Julia-like Algebraic syntax: - opsit-explang-alg-parser

Modularity, safety and adaptability

Language features come in packages, so language integrators may select just the features that are needed for their use cases. For example, to implement a calculator one may include only arithmetical operations and variables. For integrating webhooks one may allow conditionals, declaration of functions but not loops or FFI for calling arbitrary Java methods.

The language strives to provide feature flags and configuration parameters to allow configuration of language behavior, such as case sensitivity, use of default values vs. exceptions on access to undefined variables, etc.

Simplicity and ease of integration into existing systems

  • Explang Core comes with minimum dependencies.
  • Minimum types of its own: Explang works with built-in Java data types: Strings, Numbers, Collections, arrays, Character sequences.
  • Abstraction mechanisms to use same functions on different Java native types (such as Collections, arrays and character sequences).
  • Ability to use Java Beans like objects without writing glue code in Java.
  • Ability to add easily additional Java based functions and special forms to be called from Explang code.
  • Explang source strives to be simple and understandable by Java programmers. There are currently no language features that defined in Explang itself.