timfel · May 5, 2023 12:08
diff --git a/Context.java b/Context.java
 Context context = Context.newBuilder("python").
    allowAllAccess(true).
    option("python.ForceImportSite", "true").
    option("python.Executable", VENV_EXECUTABLE).
    build();
diff --git a/GraphRenderer.java b/GraphRenderer.java
 interface GraphRenderer {
  InputStream render(String function, int steps);
 }
diff --git a/Main.java b/Main.java
 Main.class.getClassLoader().getResource("venv/bin/python").getPath();
diff --git a/pom_1.xml b/pom_1.xml
 <id>enforce-graalvm-python</id>
 <phase>validate</phase>
 <goals><goal>enforce</goal></goals>
 <configuration>
  <rules>
    <requireFilesExist>
      <message>JAVA_HOME must be a GraalVM with Python installed. Download GraalVM from https://www.graalvm.org/downloads and install the Python component: `gu install python`</message>
      <files><file>${env.JAVA_HOME}/bin/graalpy</file></files>
    </requireFilesExist>
  </rules>
  <fail>true</fail>
 </configuration>
diff --git a/pom_2.xml b/pom_2.xml
 <executions>
  <execution>
    <id>Prepare venv</id>
    <phase>generate-resources</phase>
    <goals><goal>exec</goal></goals>
    <configuration>
      <executable>${env.JAVA_HOME}/bin/graalpy</executable>
      <arguments>
        <argument>-m</argument>
        <argument>venv</argument>
        <argument>venv</argument>
      </arguments>
    </configuration>
  </execution>
  <execution>
    <id>Install required packages into venv</id>
    <phase>generate-resources</phase>
    <goals><goal>exec</goal></goals>
    <configuration>
      <executable>venv/bin/pip</executable>
      <arguments>
        <argument>install</argument>
        <argument>pygal==2.4.0</argument>
      </arguments>
      <environmentVariables>
        <VIRTUAL_ENV>${project.basedir}/venv</VIRTUAL_ENV>
      </environmentVariables>
    </configuration>
  </execution>
 </executions>
diff --git a/pom_3.xml b/pom_3.xml
 <resource>
  <directory>${project.basedir}</directory>
  <includes>
    <include>venv/**/*</include>
  </includes>
 </resource>
diff --git a/PyGalRenderer.java b/PyGalRenderer.java
 Value pygalRendererClass = context.getPolyglotBindings().getMember("PygalRenderer");
 Value pygalRenderer = pygalRendererClass.newInstance();
 pygalRenderer.as(GraphRenderer.class);
diff --git a/pygalrenderer.py b/pygalrenderer.py
 import polyglot
 polyglot.export_value("PygalRenderer", PygalRenderer)
diff --git a/renderer_1.py b/renderer_1.py
 class PygalRenderer:
  def render(self, func, steps):
diff --git a/renderer_2.py b/renderer_2.py
    values = []
    x = -100
    while x < 100:
      values.append(eval(func, globals={"x": x, **math.__dict__}))
      x += 200 / steps
diff --git a/renderer_3.py b/renderer_3.py
    chart = pygal.Line(fill=False)
    chart.add(f"f(x) = {func}", values)
    svg_data = chart.render()
diff --git a/renderer_4.py b/renderer_4.py
    stream = SVGInputStream()
    stream.this.bytestream = iter(svg_data)
    return stream
diff --git a/svg_input_stream.py b/svg_input_stream.py
 class SVGInputStream(java.io.InputStream):
  def read(self, *args):
    ...
	interface GraphRenderer {
	InputStream render(String function, int steps);
	}
	<id>enforce-graalvm-python</id>
	<phase>validate</phase>
	<goals><goal>enforce</goal></goals>
	<configuration>
	<rules>
	<requireFilesExist>
	<message>JAVA_HOME must be a GraalVM with Python installed. Download GraalVM from https://www.graalvm.org/downloads and install the Python component: `gu install python`</message>
	<files><file>${env.JAVA_HOME}/bin/graalpy</file></files>
	</requireFilesExist>
	</rules>
	<fail>true</fail>
	</configuration>
	<executions>
	<execution>
	<id>Prepare venv</id>
	<phase>generate-resources</phase>
	<goals><goal>exec</goal></goals>
	<configuration>
	<executable>${env.JAVA_HOME}/bin/graalpy</executable>
	<arguments>
	<argument>-m</argument>
	<argument>venv</argument>
	<argument>venv</argument>
	</arguments>
	</configuration>
	</execution>
	<execution>
	<id>Install required packages into venv</id>
	<phase>generate-resources</phase>
	<goals><goal>exec</goal></goals>
	<configuration>
	<executable>venv/bin/pip</executable>
	<arguments>
	<argument>install</argument>
	<argument>pygal==2.4.0</argument>
	</arguments>
	<environmentVariables>
	<VIRTUAL_ENV>${project.basedir}/venv</VIRTUAL_ENV>
	</environmentVariables>
	</configuration>
	</execution>
	</executions>
	<resource>
	<directory>${project.basedir}</directory>
	<includes>
	<include>venv/*/</include>
	</includes>
	</resource>
	Value pygalRendererClass = context.getPolyglotBindings().getMember("PygalRenderer");
	Value pygalRenderer = pygalRendererClass.newInstance();
	pygalRenderer.as(GraphRenderer.class);
	import polyglot
	polyglot.export_value("PygalRenderer", PygalRenderer)
	values = []
	x = -100
	while x < 100:
	values.append(eval(func, globals={"x": x, **math.__dict__}))
	x += 200 / steps
	chart = pygal.Line(fill=False)
	chart.add(f"f(x) = {func}", values)
	svg_data = chart.render()
	stream = SVGInputStream()
	stream.this.bytestream = iter(svg_data)
	return stream
	class SVGInputStream(java.io.InputStream):
	def read(self, *args):
	...