Made 'init' and 'iteration' statements of a for-loop optionals.

Author: jamailun

dsl/src/main/java/fr/jamailun/ultimatespellsystem/dsl/nodes/statements/blocks/ForLoopStatement.java

@@ -12,6 +12,7 @@
 import lombok.Getter;
 import lombok.RequiredArgsConstructor;
 import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
 
 /**
  * A for loop.
@@ -20,17 +21,17 @@
 @RequiredArgsConstructor
 public class ForLoopStatement extends StatementNode {
 
-    private final StatementNode initialization;
+    private final @Nullable StatementNode initialization;
     private final ExpressionNode condition;
-    private final StatementNode iteration;
+    private final @Nullable StatementNode iteration;
     private final StatementNode child;
 
     @Override
     public void validateTypes(@NotNull TypesContext context) {
         TypesContext childContext = context.childContext();
-        initialization.validateTypes(childContext);
+        if(initialization != null) initialization.validateTypes(childContext);
         assertExpressionType(condition, CollectionFilter.MONO_ELEMENT, childContext, TypePrimitive.BOOLEAN);
-        iteration.validateTypes(childContext);
+        if(iteration != null) iteration.validateTypes(childContext);
         child.validateTypes(childContext);
     }
 
@@ -48,12 +49,27 @@ public void visit(@NotNull StatementVisitor visitor) {
     public static @NotNull ForLoopStatement parseForLoop(@NotNull TokenStream tokens) {
         tokens.dropOrThrow(TokenType.BRACKET_OPEN);
 
-        StatementNode init = StatementNode.parseNextStatement(tokens);
+        // Optional init
+        StatementNode init;
+        if(tokens.peek().getType() == TokenType.SEMI_COLON) {
+            init = null;
+            tokens.drop();
+        } else {
+            init = StatementNode.parseNextStatement(tokens);
+        }
+
+        // Required condition
         ExpressionNode condition = ExpressionNode.readNextExpression(tokens);
         tokens.dropOrThrow(TokenType.SEMI_COLON);
-        StatementNode iterator = StatementNode.parseNextStatement(tokens);
 
-        tokens.dropOrThrow(TokenType.BRACKET_CLOSE);
+        // Optional iteration
+        StatementNode iterator;
+        if(tokens.dropOptional(TokenType.BRACKET_CLOSE)) {
+            iterator = null;
+        } else {
+            iterator = StatementNode.parseNextStatement(tokens);
+            tokens.dropOrThrow(TokenType.BRACKET_CLOSE);
+        }
         StatementNode child = StatementNode.parseNextStatement(tokens);
 
         return new ForLoopStatement(init, condition, iterator, child);

dsl/src/main/java/fr/jamailun/ultimatespellsystem/dsl/visitor/PrintingVisitor.java

@@ -334,10 +334,10 @@ public void handleIf(@NotNull IfElseStatement statement) {
     public void handleForLoop(@NotNull ForLoopStatement statement) {
         builder.append(indent())
             .append("FOR(");
-        statement.getInitialization().visit(this);
+        if(statement.getInitialization() != null) statement.getInitialization().visit(this);
         statement.getCondition().visit(this);
         builder.append(";");
-        statement.getInitialization().visit(this);
+        if(statement.getIteration() != null) statement.getIteration().visit(this);
         builder.append("):");
         statement.getChild().visit(this);
     }

dsl/src/test/resources/parsing/corrects/blocks/for.uss

@@ -1,3 +1,14 @@
 for(define %i = 0; %i < 5; increment %i) {
-    send to %caster message "[%i]";
+    send to %caster message "i=%i";
+}
+
+%x = 12;
+for(; %x < 5; decrement %x) {
+    send to %caster message "x=%x";
+}
+
+%z = 8;
+for(; %x > 5; ) {
+    decrement %z;
+    send to %caster message "z=%z";
 }

plugin/src/main/java/fr/jamailun/ultimatespellsystem/plugin/runner/builder/SpellBuilderVisitor.java

@@ -15,6 +15,7 @@
 import fr.jamailun.ultimatespellsystem.api.runner.RuntimeStatement;
 import fr.jamailun.ultimatespellsystem.plugin.runner.nodes.functions.*;
 import lombok.Getter;
+import org.jetbrains.annotations.Contract;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
@@ -242,6 +243,7 @@ private void add(RuntimeStatement rs) {
         currentQueue.add(rs);
     }
 
+    @Contract("null -> null; !null -> !null")
     private RuntimeStatement convertOneStatement(@Nullable StatementNode dsl) {
         if(dsl == null)
             return null;

plugin/src/main/java/fr/jamailun/ultimatespellsystem/plugin/runner/nodes/blocks/ForLoopNode.java

@@ -7,17 +7,18 @@
 import fr.jamailun.ultimatespellsystem.api.runner.SpellRuntime;
 import lombok.Getter;
 import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
 
 public class ForLoopNode extends RuntimeStatement {
 
     private final RuntimeExpression condition;
-    private final RuntimeStatement initializer, iteration;
+    private final @Nullable RuntimeStatement initializer, iteration;
     @Getter private final RuntimeStatement child;
 
     //TODO make the safeguard configurable !
     private final static int MAX_ITERATIONS = 4096;
 
-    public ForLoopNode(@NotNull RuntimeStatement initializer, @NotNull RuntimeExpression condition, @NotNull RuntimeStatement iteration, @NotNull RuntimeStatement child) {
+    public ForLoopNode(@Nullable RuntimeStatement initializer, @NotNull RuntimeExpression condition, @Nullable RuntimeStatement iteration, @NotNull RuntimeStatement child) {
         this.initializer = initializer;
         this.condition = condition;
         this.iteration = iteration;
@@ -28,7 +29,7 @@ public ForLoopNode(@NotNull RuntimeStatement initializer, @NotNull RuntimeExpres
     public void run(@NotNull SpellRuntime runtimeParent) {
         SpellRuntime runtime = runtimeParent.makeChild();
 
-        initializer.run(runtime);
+        if(initializer != null) initializer.run(runtime);
         RunInstance run = new RunInstance(runtime);
 
         while(run.conditionValid()) {
@@ -56,7 +57,7 @@ private class RunInstance {
         void applyIteration() {
             iterationCount++;
             child.run(runtime);
-            iteration.run(runtime);
+            if(iteration != null) iteration.run(runtime);
         }
 
         boolean conditionValid() {