Add set capability to functions and sections.

pom.xml

@@ -6,7 +6,7 @@
 
     <groupId>org.byteskript</groupId>
     <artifactId>byteskript</artifactId>
-    <version>1.0.26</version>
+    <version>1.0.27</version>
     <name>ByteSkript</name>
     <description>A compiled JVM implementation of the Skript language.</description>
 

src/main/java/org/byteskript/skript/compiler/ElementTree.java

@@ -70,6 +70,8 @@ public void preCompile(Context context) { // Pre-compilation is (outer -> inner)
             if (compile && current instanceof Section section && !context.isSectionHeader())
                 section.preCompileInline(context, match);
             else if (compile) current.preCompile(context, match);
+        } catch (ScriptCompileError ex) {
+            throw ex;
         } catch (Throwable ex) {
             throw new ScriptCompileError(context.lineNumber(), "Failure during pre-compilation of '" + current.name() + "'", ex);
         }
@@ -91,6 +93,8 @@ public void compile(Context context) { // Post-compilation is (inner -> outer)
             if (compile && current instanceof Section section && !context.isSectionHeader())
                 section.compileInline(context, match);
             else if (compile) current.compile(context, match);
+        } catch (ScriptCompileError ex) {
+            throw ex;
         } catch (Throwable ex) {
             throw new ScriptCompileError(context.lineNumber(), "Failure during compilation of '" + current.name() + "'", ex);
         }

src/main/java/org/byteskript/skript/compiler/structure/LoopTree.java

@@ -9,10 +9,10 @@
 import mx.kenzie.foundation.MethodBuilder;
 import org.byteskript.skript.api.SyntaxElement;
 import org.byteskript.skript.compiler.Context;
-import org.byteskript.skript.error.ScriptCompileError;
 import org.byteskript.skript.lang.syntax.flow.conditional.ElseIfSection;
 import org.byteskript.skript.lang.syntax.flow.conditional.ElseSection;
 import org.objectweb.asm.Label;
+import org.objectweb.asm.Opcodes;
 
 public class LoopTree extends ProgrammaticSplitTree {
 
@@ -28,14 +28,6 @@ public LoopTree(SectionMeta owner) {
         this.end = new MultiLabel();
     }
 
-    public Label getTop() {
-        return top;
-    }
-
-    public void setTop(Label next) {
-        this.top = next;
-    }
-
     @Override
     public SectionMeta owner() {
         return owner;
@@ -57,13 +49,22 @@ public void branch(Context context) {
 
     @Override
     public void close(Context context) {
-        this.open = false;
         final MethodBuilder method = context.getMethod();
-        if (method == null) throw new ScriptCompileError(context.lineNumber(), "Loop block left unclosed.");
+        final Label top = this.getTop();
+        method.writeCode((writer, visitor) -> visitor.visitJumpInsn(Opcodes.GOTO, top));
+        this.open = false;
         method.writeCode(end.instruction());
         context.removeTree(this);
     }
 
+    public Label getTop() {
+        return top;
+    }
+
+    public void setTop(Label next) {
+        this.top = next;
+    }
+
     @Override
     public boolean permit(SyntaxElement element) {
         return element instanceof ElseIfSection || element instanceof ElseSection;

src/main/java/org/byteskript/skript/compiler/structure/TestTree.java

@@ -16,8 +16,8 @@ public class TestTree extends ProgrammaticSplitTree {
 
     private final SectionMeta owner;
     private final MultiLabel end = new MultiLabel();
-    private boolean open;
     private final Label next = new Label();
+    private boolean open;
 
     public TestTree(SectionMeta owner) {
         this.owner = owner;

src/main/java/org/byteskript/skript/compiler/structure/TryCatchTree.java

@@ -35,10 +35,6 @@ public Label getStartTry() {
         return startTry;
     }
 
-    public Label getStartCatch() {
-        return startCatch;
-    }
-
     @Override
     public SectionMeta owner() {
         return owner;
@@ -60,7 +56,18 @@ public void start(Context context) {
 
     @Override
     public void branch(Context context) {
+        final Label label = end.use();
+        final Label next = this.getStartCatch();
         this.caught = true;
+        final MethodBuilder method = context.getMethod();
+        method.writeCode(((writer, visitor) -> {
+            visitor.visitJumpInsn(Opcodes.GOTO, label);
+            visitor.visitLabel(next);
+        }));
+    }
+
+    public Label getStartCatch() {
+        return startCatch;
     }
 
     @Override

src/main/java/org/byteskript/skript/lang/syntax/flow/error/CatchSection.java

@@ -6,22 +6,16 @@
 
 package org.byteskript.skript.lang.syntax.flow.error;
 
-import mx.kenzie.foundation.MethodBuilder;
-import mx.kenzie.foundation.WriteInstruction;
 import mx.kenzie.foundation.compiler.State;
 import org.byteskript.skript.api.note.Documentation;
 import org.byteskript.skript.api.syntax.Section;
 import org.byteskript.skript.compiler.*;
-import org.byteskript.skript.compiler.structure.PreVariable;
+import org.byteskript.skript.compiler.structure.ProgrammaticSplitTree;
 import org.byteskript.skript.compiler.structure.SectionMeta;
 import org.byteskript.skript.compiler.structure.TryCatchTree;
 import org.byteskript.skript.error.ScriptCompileError;
-import org.byteskript.skript.error.ScriptParseError;
 import org.byteskript.skript.lang.element.StandardElements;
 import org.byteskript.skript.lang.handler.StandardHandlers;
-import org.byteskript.skript.lang.syntax.variable.VariableExpression;
-import org.objectweb.asm.Label;
-import org.objectweb.asm.Opcodes;
 
 @Documentation(
     name = "Catch",
@@ -45,18 +39,12 @@ public CatchSection() {
     @Override
     public Pattern.Match match(String thing, Context context) {
         if (!thing.startsWith("catch ")) return null;
-        if (!thing.contains("{")) {
-            context.getError().addHint(this, "The catch section needs to use a '{variable}'");
-            return null;
-        }
         return super.match(thing, context);
     }
 
     @Override
     public void preCompile(Context context, Pattern.Match match) throws Throwable {
-        final ElementTree holder = context.getLine().nested()[0];
-        if (!(holder.current() instanceof VariableExpression))
-            throw new ScriptParseError(context.lineNumber(), "The error must be a variable: 'catch {varname}'");
+        final ElementTree holder = context.getCompileCurrent().nested()[0];
         holder.type = StandardHandlers.SET;
         holder.compile = false;
     }
@@ -65,30 +53,7 @@ public void preCompile(Context context, Pattern.Match match) throws Throwable {
     public void compile(Context context, Pattern.Match match) throws Throwable {
         if (!(context.getTree(context.getSection(1)) instanceof TryCatchTree tree))
             throw new ScriptCompileError(context.lineNumber(), "Catch used without preceding try-section.");
-        final ElementTree holder = context.getLine().nested()[0];
-        if (!(holder.current() instanceof VariableExpression))
-            throw new ScriptParseError(context.lineNumber(), "The error must be a variable: 'catch {varname}'");
-        final Label label = tree.getEnd().use();
-        final Label next = tree.getStartCatch();
-        final MethodBuilder method = context.getMethod();
-        tree.branch(context);
-        if (method == null) throw new ScriptCompileError(context.lineNumber(), "Try/catch used outside method.");
-        context.getMethod().writeCode(((writer, visitor) -> {
-            visitor.visitJumpInsn(Opcodes.GOTO, label);
-            visitor.visitLabel(next);
-        }));
-        final int slot = context.slotOf(this.getHolderVariable(context, match));
-        method.writeCode(WriteInstruction.storeObject(slot));
-        context.setState(CompileState.CODE_BODY);
-    }
-
-    private PreVariable getHolderVariable(Context context, Pattern.Match match) {
-        final String pattern = match.groups()[0].trim();
-        assert pattern.startsWith("{") && pattern.endsWith("}");
-        final String name = pattern.substring(1, pattern.length() - 1);
-        if (name.charAt(0) == '@' || name.charAt(0) == '_' || name.charAt(0) == '!')
-            throw new ScriptCompileError(context.lineNumber(), "Holder variable must be a normal variable: '{var}'");
-        return context.getVariable(name);
+        this.compileTogether(context, match, tree);
     }
 
     @Override
@@ -100,15 +65,39 @@ public boolean allowedIn(State state, Context context) {
 
     @Override
     public void onSectionExit(Context context, SectionMeta meta) {
-        if (!(context.getTree(context.getSection()) instanceof TryCatchTree tree))
-            throw new ScriptCompileError(context.lineNumber(), "Unable to balance try/catch flow tree.");
-        context.setState(CompileState.CODE_BODY);
-        tree.close(context);
+        final ProgrammaticSplitTree current;
+        if (context.getTree(context.getSection()) instanceof TryCatchTree found) current = found;
+        else current = context.getCurrentTree();
+        if (current instanceof TryCatchTree tree) {
+            context.setState(CompileState.CODE_BODY);
+            tree.close(context);
+        }
     }
 
     @Override
     public void compileInline(Context context, Pattern.Match match) throws Throwable {
-        throw new ScriptCompileError(context.lineNumber(), "'Catch' must be used as section-header.");
+        if (!(context.getTree(context.getSection(0)) instanceof TryCatchTree tree))
+            throw new ScriptCompileError(context.lineNumber(), "Inline catch used without preceding try-section.");
+        this.compileTogether(context, match, tree);
+        tree.close(context);
+    }
+
+    @Override
+    public void preCompileInline(Context context, Pattern.Match match) throws Throwable {
+        this.preCompile(context, match);
+    }
+
+    public void compileTogether(Context context, Pattern.Match match, TryCatchTree tree) throws Throwable {
+        final ElementTree holder = context.getCompileCurrent().nested()[0];
+        tree.branch(context);
+        store:
+        {
+            holder.type = StandardHandlers.SET;
+            holder.compile = true;
+            holder.preCompile(context);
+            holder.compile(context);
+        }
+        context.setState(CompileState.CODE_BODY);
     }
 
 }

src/main/java/org/byteskript/skript/lang/syntax/flow/loop/LoopInSection.java

@@ -23,7 +23,6 @@
 import org.byteskript.skript.lang.syntax.variable.VariableExpression;
 import org.byteskript.skript.runtime.internal.OperatorHandler;
 import org.objectweb.asm.Label;
-import org.objectweb.asm.Opcodes;
 
 import java.util.Iterator;
 
@@ -50,20 +49,12 @@ public LoopInSection() {
     public Pattern.Match match(String thing, Context context) {
         if (!thing.startsWith("loop ")) return null;
         if (!thing.contains(" in ")) return null;
-        if (!thing.startsWith("loop {")) {
-            context.getError().addHint(this, "This must use a variable: 'loop {xyz} in ...'");
-            return null;
-        }
-        if (thing.charAt(6) == '@' || thing.charAt(6) == '_' || thing.charAt(6) == '!') {
-            context.getError().addHint(this, "Holder variable must be a normal variable: '{var}'");
-            return null;
-        }
         return super.match(thing, context);
     }
 
     @Override
     public void preCompile(Context context, Pattern.Match match) throws Throwable {
-        final ElementTree holder = context.getLine().nested()[0];
+        final ElementTree holder = context.getCompileCurrent().nested()[0];
         if (!(holder.current() instanceof VariableExpression))
             throw new ScriptParseError(context.lineNumber(), "The extracted element must be a variable.");
         holder.type = StandardHandlers.SET;
@@ -93,7 +84,6 @@ private void compileTogether(Context context, LoopTree tree, Pattern.Match match
         variable.internal = true;
         context.forceUnspecVariable(variable);
         final int slot = context.slotOf(variable);
-        final int holder = context.slotOf(this.getHolderVariable(context, match));
         this.writeCall(method, OperatorHandler.class.getMethod("acquireIterator", Object.class), context);
         method.writeCode(WriteInstruction.storeObject(slot));
         final Label top = new Label();
@@ -106,7 +96,14 @@ private void compileTogether(Context context, LoopTree tree, Pattern.Match match
         method.writeCode((writer, visitor) -> visitor.visitJumpInsn(153, end));
         method.writeCode(WriteInstruction.loadObject(slot));
         method.writeCode(WriteInstruction.invokeInterface(Iterator.class.getMethod("next")));
-        method.writeCode(WriteInstruction.storeObject(holder));
+        store:
+        {
+            final ElementTree holder = context.getCompileCurrent().nested()[0];
+            holder.type = StandardHandlers.SET;
+            holder.compile = true;
+            holder.preCompile(context);
+            holder.compile(context);
+        }
         context.setState(CompileState.CODE_BODY);
     }
 
@@ -121,27 +118,24 @@ public void onSectionExit(Context context, SectionMeta meta) {
         final ProgrammaticSplitTree current;
         if (context.getTree(context.getSection()) instanceof LoopTree found) current = found;
         else current = context.getCurrentTree();
-        if (!(current instanceof LoopTree tree))
-            throw new ScriptCompileError(context.lineNumber(), "Unable to balance loop flow tree.");
-        context.setState(CompileState.CODE_BODY);
-        final MethodBuilder method = context.getMethod();
-        final Label top = tree.getTop();
-        method.writeCode((writer, visitor) -> visitor.visitJumpInsn(Opcodes.GOTO, top));
-        tree.close(context);
+        if (current instanceof LoopTree tree) {
+            tree.close(context);
+            context.setState(CompileState.CODE_BODY);
+        }
     }
 
     @Override
     public void compileInline(Context context, Pattern.Match match) throws Throwable {
         if (!(context.getTree(context.getSection()) instanceof LoopTree tree))
             throw new ScriptCompileError(context.lineNumber(), "Illegal mid-statement flow break.");
         this.compileTogether(context, tree, match);
+        tree.close(context);
+        context.setState(CompileState.CODE_BODY);
     }
 
     @Override
     public void preCompileInline(Context context, Pattern.Match match) throws Throwable {
-        final ElementTree holder = context.getLine().nested()[0];
-        if (!(holder.current() instanceof VariableExpression))
-            throw new ScriptParseError(context.lineNumber(), "The extracted element must be a variable.");
+        final ElementTree holder = context.getCompileCurrent().nested()[0];
         holder.type = StandardHandlers.SET;
         holder.compile = false;
         final LoopTree tree = new LoopTree(context.getSection());

src/main/java/org/byteskript/skript/lang/syntax/function/FunctionExpression.java

@@ -8,11 +8,13 @@
 
 import mx.kenzie.foundation.MethodBuilder;
 import mx.kenzie.foundation.Type;
+import mx.kenzie.foundation.WriteInstruction;
 import org.byteskript.skript.api.note.Documentation;
 import org.byteskript.skript.api.syntax.SimpleExpression;
 import org.byteskript.skript.compiler.*;
 import org.byteskript.skript.compiler.structure.Function;
 import org.byteskript.skript.lang.element.StandardElements;
+import org.byteskript.skript.lang.handler.StandardHandlers;
 
 import java.util.ArrayList;
 import java.util.List;
@@ -91,7 +93,11 @@ public Type getReturnType() {
 
     @Override
     public void preCompile(Context context, Pattern.Match match) throws Throwable {
-        for (final ElementTree tree : context.getCompileCurrent().nested()) {
+        final ElementTree[] trees = context.getCompileCurrent().nested();
+        if (context.getHandlerMode() == StandardHandlers.SET) {
+            if (trees.length > 0) trees[0].compile = false;
+        }
+        for (final ElementTree tree : trees) {
             tree.takeAtomic = true;
         }
         super.preCompile(context, match);
@@ -103,6 +109,7 @@ public void compile(Context context, Pattern.Match match) throws Throwable {
         final FunctionDetails details = match.meta();
         final Function function = context.getDefaultFunction(details.name, details.arguments);
         method.writeCode(function.invoke(context.getType().internalName()));
+        if (!context.getHandlerMode().expectReturn()) method.writeCode(WriteInstruction.pop());
     }
 
     private record FunctionDetails(String name, int arguments) {