Added fancier tuple argument specs.

Made ArgSpec use visitor pattern to avoid problems the best way.
Merged empty tuple and non-empty tuple classes.

1 files changed, 32 insertions, 11 deletions

diff --git a/checker/src/main/java/lv/enes/orang/checker/Checker.java b/checker/src/main/java/lv/enes/orang/checker/Checker.java
index 66b7dac..f926f59 100644
--- a/checker/src/main/java/lv/enes/orang/checker/Checker.java
+++ b/checker/src/main/java/lv/enes/orang/checker/Checker.java
@@ -65,12 +65,6 @@ public class Checker implements ExpressionVisitor<Void, CheckerException>, State
         }
 
         @Override
-        public Void visitEmptyTupleExpression() {
-                // Always ok
-                return null;
-        }
-
-        @Override
         public Checker visitExpression(ExpressionStatement expr) throws CheckerException {
                 visit(expr.expr());
                 return this;
@@ -78,13 +72,40 @@ public class Checker implements ExpressionVisitor<Void, CheckerException>, State
 
         @Override
         public Void visitFnExpression(FnExpression expr) throws CheckerException {
-                var newScope = new HashSet<>(definitions);
-                for (var arg : expr.args()) {
-                        if (arg instanceof ArgSpec.Named(String name)) {
-                                newScope.add(name);
+                class Helper implements ArgSpecVisitor<HashSet<String>, CheckerException> {
+                        private final HashSet<String> scope = new HashSet<>();
+
+                        @Override
+                        public HashSet<String> visitIgnored() {
+                                // do nothing
+                                return scope;
+                        }
+
+                        @Override
+                        public HashSet<String> visitNamed(ArgSpecNamed named) throws CheckerException {
+                                if (scope.contains(named.name())) {
+                                        throw new CheckerException(STR."Redefined argument \{named.name()}!");
+                                }
+                                scope.add(named.name());
+                                return scope;
+                        }
+
+                        @Override
+                        public HashSet<String> visitTuple(ArgSpecTuple tuple) throws CheckerException {
+                                for (var child : tuple.children()) {
+                                        visit(child);
+                                }
+                                return scope;
                         }
                 }
-                new Checker(newScope).visit(expr.body());
+
+                var helper = new Helper();
+                for (var arg : expr.args()) {
+                        helper.visit(arg);
+                }
+
+                helper.scope.addAll(definitions);
+                new Checker(helper.scope).visit(expr.body());
                 return null;
         }