feat: enhance SetStatement with body support and update parsing logic

- Modify SetStatement to accept an optional body array for block statements.
- Update the Parser to handle new SetStatement structure, allowing for statements within the set.
- Introduce new token type 'EndSet' for proper parsing of set blocks.
- Adjust Interpreter logic to evaluate the body when the value is null.

Author: CodeWithKyrian

src/AST/SetStatement.php

@@ -9,8 +9,14 @@ class SetStatement extends Statement
 {
     public string $type = "Set";
 
+    /**
+     * @param Expression $assignee
+     * @param ?Expression $value
+     * @param Statement[] $body
+     */
     public function __construct(
         public Expression $assignee,
-        public Expression $value
+        public ?Expression $value,
+        public array $body = []
     ) {}
 }

src/Core/Interpreter.php

@@ -317,6 +317,10 @@ private function evaluateFilterExpression(FilterExpression $node, Environment $e
                             };
                         });
                         return new ArrayValue($operand->value);
+                    case "join":
+                        return new StringValue(implode('', $operand->value));
+                    case "string":
+                        return new StringValue(json_encode($operand->value));
                     default:
                         throw new \Exception("Unknown ArrayValue filter: {$node->filter->value}");
                 }
@@ -670,7 +674,8 @@ private function evaluateMemberExpression(MemberExpression $expr, Environment $e
 
     private function evaluateSet(SetStatement $node, Environment $environment): NullValue
     {
-        $rhs = $this->evaluate($node->value, $environment);
+        $rhs = $node->value ? $this->evaluate($node->value, $environment) : $this->evaluateBlock($node->body, $environment);
+
         if ($node->assignee->type === "Identifier") {
             $environment->setVariable($node->assignee->value, $rhs);
         } elseif ($node->assignee->type === "MemberExpression") {

src/Core/Parser.php

@@ -191,11 +191,23 @@ private function parseSetStatement(): Statement
 
         if ($this->is(TokenType::Equals)) {
             $this->current++;
-            $value = $this->parseSetStatement();
+            $value = $this->parseExpression();
 
-            return new SetStatement($left, $value);
+            return new SetStatement($left, $value, []);
+        } else {
+            $body = [];
+
+            $this->expect(TokenType::CloseStatement, "Expected closing statement token");
+
+            while ($this->not(TokenType::OpenStatement, TokenType::EndSet)) {
+                $body[] = $this->parseAny();
+            }
+
+            $this->expect(TokenType::OpenStatement, "Expected opening statement token");
+            $this->expect(TokenType::EndSet, "Expected endset token");
+
+            return new SetStatement($left, null, $body);
         }
-        return $left;
     }
 
     private function parseIfStatement(): IfStatement

src/Core/Token.php

@@ -17,6 +17,7 @@ class Token
         'is' => TokenType::Is,
         'if' => TokenType::If,
         'else' => TokenType::Else,
+        'endset' => TokenType::EndSet,
         'endif' => TokenType::EndIf,
         'elif' => TokenType::ElseIf,
         'endfor' => TokenType::EndFor,

src/Core/TokenType.php

@@ -47,6 +47,7 @@ enum TokenType: string
     case Is = "Is";
     case NotIn = "NotIn";
     case Else = "Else";
+    case EndSet = "EndSet";
     case EndIf = "EndIf";
     case ElseIf = "ElseIf";
     case EndFor = "EndFor";