M4J - MUMPS for JAVA

An attempt at making a MUMPS runtime environment for the java virtual machine (JVM) similar to how other programming languages such as Groovy, Scala, Ruby, Python etc. have utilized the JVM platform

• ANTLR-based Lexer/parser that can interpret and execute M code
• Compiler that can compile M code to JVM byte-code (very early, only 1-2 commands implemented)
• Globals API/proxy
  • Plain java persistence (Using H2's MVStore storage engine)
  • Connecters back to InterSystems Cache (Using cache extreme drivers)
• Runtime environment (~40% of the system commands/functions implemented)
• Shell/console tool including:
  • command history
  • TAB-expansion of variable and routine names
  • VI/EMACS-style key bindings

About

• Created by Brian Bray, President/Founder of BrayLabs
• Initially created as an exercise in learning M while working for the VA on the Health Management Platform (HMP). The original project, not the current eHMP project.
• This is an enhanced version of what was originally published as open source software by the VA to OSEHRA,
• Questions/comments can be directed to me via email, or I also still lurk on the Hardhats list a bit.

Prerequisites

• Java (7 or 8)
• Maven
• InterSystems Cache (Optional)
• ANTLR4 Eclipse Plugin (Optional)

Known issues

• Currently will fail to fetch Cache dependencies, might need to comment them out or install into local maven repo manually
• CacheGlobalStore doesn't work on OSX, the cache driver causes core dumps
• There is still some quirky M code that the ANTLR grammar cannot handle
• Not all the commands/system functions are implemented nor are they fully implemented and completely compatible
• Some forms of indirection work, others do not

Quick start

git clone https://github.com/braylabs/m4j.git
cd m4j
mvn package

Quick Start - Launch M4J Console

java -jar target/m4j-0.1.jar
Welcome to M4J console, type 'H' to quit

M4J> S SAY="HELLO",NAME="WORLD"
M4J> W SAY_" "_NAME
HELLO WORLD
M4J>

Quick Start - M4J Compiler

Currently only 1 M routine in src/test/ compiles. This should generate a class file that can be utilized by regular java apps.

m4jc -package=m4j. -dest=target/m4jc/m4j src/test/java/com/braylabs/m4j/lang/M4JCTST.int

Quick Start - Java Code Example

import java.io.File;
import java.io.IOException;

import com.braylabs.m4j.lang.M4JRuntime;
import com.braylabs.m4j.lang.M4JRuntime.M4JProcess;
import com.braylabs.m4j.lang.RoutineProxy;
import com.braylabs.m4j.lang.RoutineProxy.MInterpRoutineProxy;
import com.braylabs.m4j.lang.RoutineProxy.JavaClassProxy.M4JEntryPoint;
import com.braylabs.m4j.lang.RoutineProxy.JavaClassProxy.M4JRoutine;

import static com.braylabs.m4j.lang.MUMPS.*;

public class Demo {
	public static void main(String[] args) throws IOException {
	  // Create a M4J runtime and register 2 routines:
	  // 1) Register an annotated java static method as a M routine
	  // 2) Load/Parse a M-language routine file from disk
		M4JRuntime runtime = new M4JRuntime();
		runtime.registerRoutine(new RoutineProxy.JavaClassProxy(MyFirstM4JRoutine.class));
		runtime.registerRoutine(new MInterpRoutineProxy(new File("src/main/mumps/XLFSTR.int")));
		
		// Create a M4J Process and evaluate a simple line
		M4JProcess proc = new M4JProcess(runtime, 123);
		proc.getInterpreter().evalLine("W !,$$SAY^HELLO($$UP^XLFSTR(\"world\")),!");
	}

	// Register this class as a M routine named 'HELLO'
	@M4JRoutine(name="HELLO")
	public static class MyFirstM4JRoutine {
		
		// With an entry point named 'SAY'
		@M4JEntryPoint(name="SAY")
		public static String hello(String val) {
			return "Hello: " + val;
		}
	}
}