eo/eo-maven-plugin

This is Maven plugin for EO.

Here is a simple program that gets a year from command line and tells you whether it's leap or not:

[args...] > main
  [y] > leap
    or. > @
      and.
        eq. (mod. y 4) 0
        not. (eq. (mod. y 100) 0)
      eq. (mod. y 400) 0
  QQ.io.stdout > @
    QQ.txt.sprintf
      "%d is %sa leap year!"
      (args.get 0).as-int > year!
      if (leap year:y) "" "not "

In order to compile this program, put it into src/main/eo/main.eo and then create a file pom.xml with this content (it's just a sample):

<project>
  [...]
  <build>
    <plugins>
      <plugin>
        <groupId>org.eolang</groupId>
        <artifactId>eo-maven-plugin</artifactId>
        <version>0.36.0</version>
        <executions>
          <execution>
            <goals>
              <goal>register</goal>
              <goal>assemble</goal>
              <goal>transpile</goal>
            </goals>
          </execution>
        </executions>
      </plugin>
      <plugin>
        <groupId>org.codehaus.mojo</groupId>
        <artifactId>exec-maven-plugin</artifactId>
        <executions>
          <execution>
            <phase>test</phase>
            <goals>
              <goal>java</goal>
            </goals>
          </execution>
        </executions>
        <configuration>
          <mainClass>org.eolang.Main</mainClass>
          <arguments>
            <argument>main</argument>
            <argument>2008</argument>
          </arguments>
        </configuration>
      </plugin>
    </plugins>
  </build>
</project>

Then, you just run mvn clean test (you will need Maven 3.3+) and the .eo file will be parsed to .xml files, transformed to .java files, and then compiled to .class files. You can see them all in the target directory. You will need Java 8+.

How it Works?

The entire process of turning an .eo program into an executable binary code consists of a few high-level steps, which must be done one after another:

• Parsing. It's done by the org.eolang.parser.EoSyntax class in the eo-parser module. It takes the source code in a plain text format and parses into XML document, using ANTLR4 and Xembly. The output of the parser you can find in the target/eo/parse directory. Parsed objects which are versioned (normally pulled from Objectionary) are cached in .eo/parsed folder.

• Optimization. There are a number of XSL transformations that need to be done with the XML document in order to make it ready for compilation. Each transformation has its own .xsl file in the eo-parser directory. The class org.eolang.parser.Program is responsible for making XSLT transformations and the entire list of them is stored in the org.eolang.parser.Pack class. Some of XLST files are sanity checks (or linters). The output of each transformation you can find in the target/eo/optimize directory.

• Compilation. The class org.eolang.maven.TranspileMojo in the eo-maven-plugin module is responsible for taking parsed and optimized XMIRs and then transforming the XML document into a collection of .java files. There are a number of transformations that do this, they all exist in .xsl files. The output of this step you can find in the target/generated-sources directory.

There is also a module called eo-runtime, which includes both .eo and .java code for most popular and important objects that any of you will need in order to write even a simple EO program. There are objects like string, int, sprintf, stdout, and so on. By the way, you may want to contribute there by creating new objects.

Objectionary objects cache

If any external object is used in EO program it will be pulled from Objectionary home. By default, during compilation the plugin will check local cache (~/.eo) for required objects and only download (and cache) them in case they are not found locally.

This behaviour can be changed to always download objects from remote by providing Maven option -U (see Maven CLI docs):

mvn -U clean install

If you want to build your project or run your tests which use eo-maven-plugin, you can change stack size for your purposes by stack-size option:

mvn clean install -Pqulice -Dstack-size=1M

where 1M is size of stack. By default stack-size = 256M in eo-maven-plugin, maximum size is 1G.

How to run Integration Tests only

If you want to run a specific integration test without waiting until other unit or integration tests are executed you need to go to eo-maven-plugin directory and execute the next command:

mvn clean integration-test invoker:run -Dinvoker.test=fibonacci -DskipTests

Here fibonacci is the name of the desired integration test, -DskipTests is used in order to skip eo-maven-plugin unit tests.

How to disable Integration Tests

It is sometime necessary to temporary disable the integration tests (for example for introducing braking changes into plugin or EO runtime). This can be achieved by disabling maven-invoker-plugin execution within eo-maven-plugin/pom.xml:

<plugins>
  ...
  <plugin>
    <artifactId>maven-invoker-plugin</artifactId>
    <version>0.36.0</version>
    <configuration>
        <skipInstallation>true</skipInstallation>
        <skipInvocation>true</skipInvocation>
    </configuration>
  </plugin>
  ...
</plugins>