Sodg-Maven-Plugin

The sodg-maven-plugin builds a graph from an EO program. SODG stands for Surging Object DiGraph. The primary consumer of SODG graphs is the reo project. You can find some examples of .sodg files.

Quick Start

Then, start with a simple EO program in the order.eo file:

[qty price] > order
  qty.mul > cost
    price

That can be translated to the following XMIR:

<object>
   <o name="order">
      <o base="ξ" name="xi🌵"/>
      <o base="∅" name="qty"/>
      <o base="∅" name="price"/>
      <o base="ξ.qty.mul" name="cost">
         <o as="α0" base="ξ.price"/>
      </o>
   </o>
</object>

Then, add this plugin to your pom.xml:

<plugin>
   <groupId>org.eolang</groupId>
   <artifactId>sodg-maven-plugin</artifactId>
   <version>0.0.3</version>
   <executions>
      <execution>
         <goals>
            <goal>sodg</goal>
         </goals>
      </execution>
   </executions>
</plugin>

Or invoke it directly:

mvn org.eolang:sodg-maven-plugin:0.0.3:sodg

You should see order.sodg file being created under target/eo/sodg folder, with the following content:

formation(b1, "xi🌵", "qty", "price", "cost")
dispatch(b2, b1, "xi🌵")
dispatch(b3, b1, "qty")
dispatch(b4, b1, "price")
dispatch(b5, b3, "mul")
application(b6, b5, α0, b4)
put(b1, "cost", b6)

SODG Format

To generate these text files, we first use an intermediate XML format:

<sodg>
   <i name="formation">
      <a>b1</a>
      <a>xi🌵</a>
      <a>qty</a>
      <a>price</a>
      <a>cost</a>
   </i>
   <i name="dispatch">
      <a>b2</a>
      <a>b1</a>
      <a>xi🌵</a>
   </i>
   <i name="dispatch">
      <a>b3</a>
      <a>b1</a>
      <a>qty</a>
   </i>
   <i name="dispatch">
      <a>b4</a>
      <a>b1</a>
      <a>price</a>
   </i>
   <i name="dispatch">
      <a>b5</a>
      <a>b3</a>
      <a>mul</a>
   </i>
   <i name="application">
      <a>b6</a>
      <a>b5</a>
      <a>α0</a>
      <a>b4</a>
   </i>
   <i name="put">
      <a>b1</a>
      <a>cost</a>
      <a>b6</a>
   </i>
</sodg>

This DSL consists of these commands:

• formation(o, attr0, attr1, ...) – creates a new formation object
• dispatch(o, base, attr) – creates a new dispatch object
• application(o, proto, attr, arg) – creates a new application object
• delta(o, data) – sets Δ-asset to the object
• lambda(o, name) - sets λ-asset to the object
• put(o, attr, kid) – sets attribute of the object

The sodg-maven-plugin performs the following steps:

1. Turns .xmir into intermediate XML
2. Turns XML into a .dot graph (renderable by GraphViz)
3. Turns XML into .sodg text file (with DSL)
4. Turns XML into .xe (Xembly) file that, if executed, would generate a graph in XML
5. Turns XML into .graph.xml, which is a graph as XML

The .sodg file is essentially a sequence of instructions for a virtual machine that parses them. An example of such a machine can be found in the SODG repo. When the graph is built by the virtual machine, it must be possible to execute a program using graph traversing algorithm. Once the graph is built, it can be used to execute a program via a graph traversal algorithm. An example of such an executor is reo.

Configuration

You can configure the plugin goal's behavior using <configuration/>. The most important parameters are:

• scope - current object scope, default: compile.
• generateSodgXmlFiles - shall we generate .sodg.xml files with SODGs?
• generateXemblyFiles - shall we generate .xe files with Xembly instructions graph?
• generateGraphFiles - shall we generate .graph.xml files with XML graph?
• generateDotFiles - shall we generate .dot files with DOT language graph commands?
• sodgIncludes - object names to participate in SODG generation, in the glob format, default: **.
• sodgExcludes - object names to be excluded from SODG generation, in the glob format.
• failOnXmirErrors - shall we fail SODG generation if XMIRs contain errors?

For failOnXmirErrors default value is true. It means that, if .xmir contains /object/errors, then SODG generation will be failed:

<object>
   ...
   <errors>
      <error check="validate-object-name" severity="critical">...</error>
   </errors>
</object>

If failOnXmirErrors set to false, then even .xmir contains /object/errors, the plugin will try to convert it to SODG.

How to Contribute

Fork repository, make changes, then send us a pull request. We will review your changes and apply them to the master branch shortly, provided they don't violate our quality standards. To avoid frustration, before sending us your pull request please run full Maven build:

mvn clean install -Pqulice

You will need Maven 3.3+ and Java 11+ installed.