Allow redirection of print output.

Author: Moderocky

pom.xml

@@ -6,7 +6,7 @@
 
     <groupId>org.byteskript</groupId>
     <artifactId>byteskript</artifactId>
-    <version>1.0.31</version>
+    <version>1.0.32</version>
     <name>ByteSkript</name>
     <description>A compiled JVM implementation of the Skript language.</description>
 

src/main/java/org/byteskript/skript/lang/syntax/flow/execute/RunAsyncEffect.java

@@ -93,6 +93,7 @@ public void compile(Context context, Pattern.Match match) throws Throwable {
             final MethodErasure bootstrap = new MethodErasure(LambdaMetafactory.class.getMethod("metafactory", MethodHandles.Lookup.class, String.class, MethodType.class, MethodType.class, MethodHandle.class, MethodType.class));
             method.writeCode((writer, visitor) -> visitor.visitInvokeDynamicInsn("run", creator.getDescriptor(), new Handle(Opcodes.H_INVOKESTATIC, "java/lang/invoke/LambdaMetafactory", bootstrap.name(), bootstrap.getDescriptor(), false), org.objectweb.asm.Type.getType("()V"), new Handle(6, internal, runnable.name(), runnable.getDescriptor(), false), org.objectweb.asm.Type.getType("()V")));
             // todo hold synchronicity to following sleep
+            // todo error protection?
         }
         final Method target = ExtractedSyntaxCalls.class.getMethod("runOnAsyncThread", Runnable.class);
         this.writeCall(method, target, context);

src/main/java/org/byteskript/skript/lang/syntax/generic/PrintEffect.java

@@ -15,6 +15,7 @@
 import org.byteskript.skript.compiler.Pattern;
 import org.byteskript.skript.compiler.SkriptLangSpec;
 import org.byteskript.skript.lang.element.StandardElements;
+import org.byteskript.skript.runtime.internal.ExtractedSyntaxCalls;
 
 import java.io.PrintStream;
 
@@ -37,17 +38,10 @@ public PrintEffect() {
         super(SkriptLangSpec.LIBRARY, StandardElements.EFFECT, "print %Object%");
     }
 
-    @Override
-    public void preCompile(Context context, Pattern.Match match) throws Throwable {
-        final MethodBuilder method = context.getMethod();
-        method.writeCode(WriteInstruction.getField(System.class.getField("out")));
-        super.preCompile(context, match);
-    }
-    
     @Override
     public void compile(Context context, Pattern.Match match) throws Throwable {
         final MethodBuilder method = context.getMethod();
-        method.writeCode(WriteInstruction.invokeVirtual(PrintStream.class.getMethod("println", Object.class)));
+        method.writeCode(WriteInstruction.invokeStatic(ExtractedSyntaxCalls.class.getMethod("print", Object.class)));
         context.setState(CompileState.CODE_BODY);
     }
 

src/main/java/org/byteskript/skript/runtime/Skript.java

@@ -20,6 +20,7 @@
 import org.byteskript.skript.error.ScriptCompileError;
 import org.byteskript.skript.error.ScriptLoadError;
 import org.byteskript.skript.error.ScriptRuntimeError;
+import org.byteskript.skript.runtime.event.Unload;
 import org.byteskript.skript.runtime.internal.*;
 import org.byteskript.skript.runtime.threading.*;
 import org.byteskript.skript.runtime.type.Converter;
@@ -83,6 +84,8 @@ public final class Skript {
     final List<Script> scripts = new ArrayList<>(); // the only strong reference, be careful!
     @Ignore
     final Map<Converter.Data, Converter<?, ?>> converters;
+    @Ignore
+    protected PrintStream out = System.out;
 
     @Description("""
         Create a Skript runtime with a custom (non-default) Skript compiler.
@@ -745,6 +748,7 @@ public void unloadScript(Class<?> main) {
         """)
     @GenerateExample
     public void unloadScript(Script script) {
+        final Unload unload = new Unload(script);
         script.stop();
         synchronized (events) {
             for (final EventHandler value : events.values()) {
@@ -755,8 +759,9 @@ public void unloadScript(Script script) {
                 }
             }
         }
-        scripts.remove(script);
+        this.scripts.remove(script);
         UnsafeAccessor.graveyard(script);
+        this.runEvent(unload);
     }
 
     @Description("""
@@ -983,6 +988,26 @@ public Script loadScript(final File source, final String name)
         }
     }
 
+    //region Output
+    
+    /**
+     * Set the current print stream used by the `print` effect.
+     * This can be used to redirect output in a particular state.
+     */
+    public void setOutput(final PrintStream out) {
+        if (out == null) this.out = System.out;
+        else this.out = out;
+    }
+    
+    public void println(Object object) {
+        this.out.println(object);
+    }
+    
+    public void print(Object object) {
+        this.out.print(object);
+    }
+    //endregion
+    
     @Description("""
         Generates a script thread from the given process.
         """)

src/main/java/org/byteskript/skript/runtime/event/Unload.java

@@ -0,0 +1,34 @@
+/*
+ * Copyright (c) 2021 ByteSkript org (Moderocky)
+ * View the full licence information and permissions:
+ * https://github.com/Moderocky/ByteSkript/blob/master/LICENSE
+ */
+
+package org.byteskript.skript.runtime.event;
+
+import mx.kenzie.autodoc.api.note.Ignore;
+import org.byteskript.skript.api.Event;
+import org.byteskript.skript.api.note.EventValue;
+import org.byteskript.skript.runtime.Script;
+
+@Ignore
+public class Unload extends Event {
+    
+    protected final String name, path;
+    
+    public Unload(Script script) {
+        this.name = script.getSimpleName();
+        this.path = script.getPath();
+    }
+    
+    @EventValue("name")
+    public String getName() {
+        return name;
+    }
+    
+    @EventValue("script")
+    public String getPath() {
+        return path;
+    }
+    
+}

src/main/java/org/byteskript/skript/runtime/internal/ExtractedSyntaxCalls.java

@@ -98,6 +98,11 @@ public static void runOnMainThread(final Instruction<?> runnable) throws Throwab
         }
     }
 
+    public static void print(Object object) throws Throwable {
+        final Skript skript = findInstance();
+        skript.println(object);
+    }
+    
     public static String readSystemInput() throws Throwable {
         final BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
         return reader.readLine();

src/test/resources/tests/monitor.bsk

@@ -4,19 +4,14 @@ function test:
         set {lock} to a new object
         monitor {lock}
         set {thread} to the current process
-        set {lock} to a new object
         set {@thing} to false
         set {var} to a new runnable:
             monitor {lock}
-            assert {@thing} is null
             set {@thing} to true
             wake {thread}
         monitor {lock}:
             assert {@thing} is false
-            run {var} in the background
-            delete {@thing}
-            assert {@thing} is null
-        sleep
+        wait for {var}
         assert {@thing} is true
         delete {@thing}
         return true