fvm is an extensible stack-based self-optimizing VM.
fvm comes with an example interpreter for a simple language called ednlang.
Here's a ednlang program that calculates and prints factorial(5):
;; import the standard library
{:op :requires
:value ["lib/std.edn"]}
;; define a new opcode for factorial
{:op :defop
:name :fact
:value [{:op :push
:value 0}
{:op :eq?
:then [{:op :pop}
{:op :pop}
{:op :push
:value 1}]
:else [{:op :pop}
{:op :dup}
{:op :dec}
{:op :fact}
{:op :mul}]}]}
;; call it
{:op :push
:value 5}
{:op :fact}
;; print the result
{:op :println}To run the example factorial program, do:
$ lein run test/fact.edn
Make sure you have GraalVM installed and $GRAALVM_HOME pointing to it, then do:
$ ./compile
Now you can do:
$ target/fvm test/fact.edn
$ lein eftest
- A pure Clojure library for writing JITing VMs (like RPython and Truffle/GraalVM)
- Simple, functional interface
- Hot loops are traced and inlined at runtime
- Simple language implemented on top of fvm
- Custom ops (like
factabove) are inlined and called at runtime - No recursion limit - try running the factorial program for large values
- Code is data is code - anonymous ops can be stored and called
- Designed to be easily parsable and an easy compilation target
- Does not require a GC, being completely stack based
This is a research project with rough edges - here be dragons.
Copyright © 2020 Divyansh Prakash
This program and the accompanying materials are made available under the terms of the Eclipse Public License 2.0 which is available at http://www.eclipse.org/legal/epl-2.0.
This Source Code may also be made available under the following Secondary Licenses when the conditions for such availability set forth in the Eclipse Public License, v. 2.0 are satisfied: GNU General Public License as published by the Free Software Foundation, either version 2 of the License, or (at your option) any later version, with the GNU Classpath Exception which is available at https://www.gnu.org/software/classpath/license.html.