When comparing Armed Bear Common Lisp vs Xtend, the Slant community recommends Xtend for most people. In the question“What are the best languages that run on the JVM?” Xtend is ranked 8th while Armed Bear Common Lisp is ranked 14th. The most important reason people chose Xtend is:
Lambdas are written like Smalltalk's blocks. If it's the last argument, it can go after the parentheses like Ruby's blocks. Parentheses on method calls are optional.
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Pros
Pro Can be integrated into java programs for scripting capabilities
Pro Fairly simple to learn and use
Written and interoperable with Java.
Pro Ruby-like syntactic conveniences
Lambdas are written like Smalltalk's blocks. If it's the last argument, it can go after the parentheses like Ruby's blocks. Parentheses on method calls are optional.
Pro Type inference
It uses Java's static type system, but you don't have to declare the type of everything all the time, since the Xtend compiler can usually figure it out. This also dramatically cuts down on Java's infamous verbosity.
Pro Code runs just as fast as Java
Because Xtend relies heavily on JDK and Android classes, it runs just as fast as native Java code.
Pro Easy to switch back to Java
Xtend is a low-risk option. Because it compiles to human-readable Java, if you decide you don't like it for your project, you can just switch back to Java without losing your work.
Pro Extend even library classes with new methods
This is where it gets its name. You can open classes and add new methods, kind of like Ruby. (Of course this has to be compiled to Java, so really it lives in a kind of helper class.)
Pro Succint
Uses functional features ,which are very concise and idiomatic. Plus it has annotations, which cuts down on the Java boilerplate.
Pro Better defaults than Java
Methods are public if you don't specify, and fields are private. Locals declared with val
in Xtend are final
in Java. This dramatically cuts down on Java's infamous verbosity.
Cons
Con The java API isn't always enough
Some of its features are made private and can't easily be modified from java.
Con Can be slow and clunky because of the java overhead
It is using java.
Java is slow.
Ergo: abcl is slow.
Con Difficult to configure in Android Studio
Con Slower compilation
Unlike most JVM languages, Xtend compiles to Java rather than directly to JVM bytecode. So you have to compile everything four times for Android: from Xtend to Java, from Java to JVM bytecode (.class files), from .class to .dex bytecode, and then AOT compilation from .dex to native ARM upon installation. This can really slow down development and testing vs a more interactive language like Clojure.
