The 'repeat' statement now adds an index variable, so that its inner scope can know the iteration index

Author: jamailun

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

@@ -14,8 +14,16 @@
 
 import java.util.Optional;
 
+/**
+ * Statement of a {@code repeat <N> times}.
+ */
 public class RepeatStatement extends BlockHolder {
 
+    /**
+     * Name of the variable set by this statement.
+     */
+    public static final String INDEX_VARIABLE = "_repeat_index";
+
     private final ExpressionNode delay; // optional
     @Getter private @NotNull final ExpressionNode count;
     @Getter private @NotNull final ExpressionNode period;
@@ -29,12 +37,15 @@ public RepeatStatement(StatementNode child, ExpressionNode delay, @NotNull Expre
 
     @Override
     public void validateTypes(@NotNull TypesContext context) {
+        TypesContext childContext = context.childContext();
+        childContext.promiseVariable(INDEX_VARIABLE, TypePrimitive.NUMBER.asType());
+
         if(delay != null)
-            assertExpressionType(delay, CollectionFilter.MONO_ELEMENT, context, TypePrimitive.DURATION);
-        assertExpressionType(count, CollectionFilter.MONO_ELEMENT, context, TypePrimitive.NUMBER);
-        assertExpressionType(period, CollectionFilter.MONO_ELEMENT, context, TypePrimitive.DURATION);
+            assertExpressionType(delay, CollectionFilter.MONO_ELEMENT, childContext, TypePrimitive.DURATION);
+        assertExpressionType(count, CollectionFilter.MONO_ELEMENT, childContext, TypePrimitive.NUMBER);
+        assertExpressionType(period, CollectionFilter.MONO_ELEMENT, childContext, TypePrimitive.DURATION);
 
-        child.validateTypes(context.childContext());
+        child.validateTypes(childContext.childContext());
     }
 
     public Optional<ExpressionNode> getDelay() {

dsl/src/main/java/fr/jamailun/ultimatespellsystem/dsl/nodes/type/TypesContext.java

@@ -46,7 +46,7 @@ public Type computeType(TypesContext context) {
      * Create a new context, and register the '%caster' variable.
      */
     public TypesContext() {
-        variables.put("caster", new VariableDefinition(TypePrimitive.ENTITY.asType()));
+        promiseVariable("caster", TypePrimitive.ENTITY.asType());
     }
 
     /**
@@ -61,6 +61,15 @@ public void registerVariable(String varName, ExpressionNode variable) {
         variables.put(varName, new VariableDefinition(variable));
     }
 
+    /**
+     * Guarantee a variable will be set by a runtime implementation.
+     * @param name the name of the variable.
+     * @param type the type of the variable.
+     */
+    public void promiseVariable(String name, Type type) {
+        variables.put(name, new VariableDefinition(type));
+    }
+
     public void registerVariable(String varName, TokenPosition position, Type type) {
         if("caster".equals(varName)) {
             throw new SyntaxException(position, "Cannot override variable '%" + varName + "'.");

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

@@ -1,6 +1,7 @@
 package fr.jamailun.ultimatespellsystem.plugin.runner.nodes.blocks;
 
 import fr.jamailun.ultimatespellsystem.api.UltimateSpellSystem;
+import fr.jamailun.ultimatespellsystem.dsl.nodes.statements.blocks.RepeatStatement;
 import fr.jamailun.ultimatespellsystem.dsl.nodes.type.Duration;
 import fr.jamailun.ultimatespellsystem.api.runner.RuntimeExpression;
 import fr.jamailun.ultimatespellsystem.api.runner.RuntimeStatement;
@@ -29,12 +30,18 @@ public void run(@NotNull SpellRuntime runtime) {
         long delayTicks = delay == null ? 0 : delay.toTicks();
 
         UltimateSpellSystem.runTaskRepeat(
-                () -> {
-                    try {
-                        child.run(runtime);
-                    } catch (Throwable t) {
-                        UltimateSpellSystem.logError("Uncaught "+t.getClass().getSimpleName()+" on RunRepeatNode#run : " + t.getMessage());
-                        t.printStackTrace();
+                new Runnable() {
+                    private int count = 0;
+                    @Override
+                    public void run() {
+                        runtime.variables().set(RepeatStatement.INDEX_VARIABLE, count);
+                        try {
+                            child.run(runtime);
+                        } catch (Throwable t) {
+                            UltimateSpellSystem.logError("Uncaught "+t.getClass().getSimpleName()+" on RunRepeatNode#run : " + t.getMessage());
+                            t.printStackTrace();
+                        }
+                        count++;
                     }
                 },
                 count,