feat: evaluator unknown operator error

Author: DeveloperC286

src/evaluator/boolean/mod.rs

@@ -5,7 +5,7 @@ pub fn evaluate(boolean_token: Token) -> Object {
     match boolean_token {
         Token::TRUE => Object::TRUE,
         Token::FALSE => Object::FALSE,
-        _ => Object::NULL,
+        _ => panic!("Boolean token not a boolean token."),
     }
 }
 

src/evaluator/infix/mod.rs

@@ -35,7 +35,7 @@ pub fn evaluate(left_hand: Expression, operator_token: Token, right_hand: Expres
                         true => Object::TRUE,
                         false => Object::FALSE,
                     },
-                    _ => Object::NULL,
+                    _ => panic!("Operator token is not operator token."),
                 },
                 _ => Object::TYPE_MISMATCH,
             }
@@ -58,15 +58,15 @@ fn evaluate_same_boolean(operator_token: Token) -> Object {
     match operator_token {
         Token::EQUALS => Object::TRUE,
         Token::NOT_EQUALS => Object::FALSE,
-        _ => Object::NULL,
+        _ => Object::UNKNOWN_OPERATOR,
     }
 }
 
 fn evaluate_opposite_boolean(operator_token: Token) -> Object {
     match operator_token {
         Token::EQUALS => Object::FALSE,
         Token::NOT_EQUALS => Object::TRUE,
-        _ => Object::NULL,
+        _ => Object::UNKNOWN_OPERATOR,
     }
 }
 

src/evaluator/infix/tests/mod.rs

@@ -64,3 +64,23 @@ fn test_evaluator_infix_boolean_expressions(code: &str, snapshot_name: &str) {
 fn test_evaluator_infix_type_mismatch_expressions(code: &str, snapshot_name: &str) {
     assert_expected_returned_object!(code, snapshot_name);
 }
+
+#[rstest(
+    code,
+    snapshot_name,
+    case(
+        "true + TRUE",
+        "test_evaluator_infix_unknown_operator_expressions_case1"
+    ),
+    case(
+        "5 + 10; FALSE * FALSE; 7",
+        "test_evaluator_infix_unknown_operator_expressions_case2"
+    ),
+    case(
+        "if (5 < 10) { FALSE + FALSE }",
+        "test_evaluator_infix_unknown_operator_expressions_case3"
+    )
+)]
+fn test_evaluator_infix_unknown_operator_expressions(code: &str, snapshot_name: &str) {
+    assert_expected_returned_object!(code, snapshot_name);
+}

src/evaluator/infix/tests/snapshots/rust_monkey_interpreter__evaluator__infix__tests__test_evaluator_infix_unknown_operator_expressions_case1.snap

@@ -0,0 +1,5 @@
+---
+source: src/evaluator/infix/tests/mod.rs
+expression: "crate::evaluator::evaluate(crate::syntax_analysis::get_abstract_syntax_tree(crate::lexical_analysis::get_tokens(code.to_string())))"
+---
+"UNKNOWN_OPERATOR"

src/evaluator/infix/tests/snapshots/rust_monkey_interpreter__evaluator__infix__tests__test_evaluator_infix_unknown_operator_expressions_case2.snap

@@ -0,0 +1,5 @@
+---
+source: src/evaluator/infix/tests/mod.rs
+expression: "crate::evaluator::evaluate(crate::syntax_analysis::get_abstract_syntax_tree(crate::lexical_analysis::get_tokens(code.to_string())))"
+---
+"UNKNOWN_OPERATOR"

src/evaluator/infix/tests/snapshots/rust_monkey_interpreter__evaluator__infix__tests__test_evaluator_infix_unknown_operator_expressions_case3.snap

@@ -0,0 +1,5 @@
+---
+source: src/evaluator/infix/tests/mod.rs
+expression: "crate::evaluator::evaluate(crate::syntax_analysis::get_abstract_syntax_tree(crate::lexical_analysis::get_tokens(code.to_string())))"
+---
+"UNKNOWN_OPERATOR"

src/evaluator/integer/mod.rs

@@ -6,7 +6,7 @@ pub fn evaluate(integer_token: Token) -> Object {
         Token::INTEGER { literal } => Object::INTEGER {
             value: literal.parse().unwrap(),
         },
-        _ => Object::NULL,
+        _ => panic!("Integer token not a integer token."),
     }
 }
 

src/evaluator/mod.rs

@@ -14,6 +14,10 @@ mod return_statement;
 pub fn evaluate(abstract_syntax_tree: AbstractSyntaxTree) -> Object {
     let mut object = Object::NULL;
 
+    if !abstract_syntax_tree.syntax_parsing_errors.is_empty() {
+        panic!("Syntax errors unable to evaluate.");
+    }
+
     for syntax_tree_node in abstract_syntax_tree.abstract_syntax_tree {
         object = evaluate_node(syntax_tree_node);
 
@@ -22,7 +26,7 @@ pub fn evaluate(abstract_syntax_tree: AbstractSyntaxTree) -> Object {
                 object = *value;
                 break;
             }
-            Object::TYPE_MISMATCH => break,
+            Object::TYPE_MISMATCH | Object::UNKNOWN_OPERATOR => break,
             _ => {}
         }
     }
@@ -37,7 +41,7 @@ fn evaluate_block(block: Block) -> Object {
         object = evaluate_node(syntax_tree_node);
 
         match object.clone() {
-            Object::RETURN { value: _ } | Object::TYPE_MISMATCH => break,
+            Object::RETURN { value: _ } | Object::TYPE_MISMATCH | Object::UNKNOWN_OPERATOR => break,
             _ => {}
         }
     }

src/evaluator/object/mod.rs

@@ -9,4 +9,5 @@ pub enum Object {
     FALSE,
     NULL,
     TYPE_MISMATCH,
+    UNKNOWN_OPERATOR,
 }

src/evaluator/prefix/mod.rs

@@ -8,13 +8,13 @@ pub fn evaluate(prefix_token: Token, right_hand_expression: Expression) -> Objec
         Token::NOT => match object {
             Object::TRUE => Object::FALSE,
             Object::FALSE => Object::TRUE,
-            _ => Object::NULL,
+            _ => Object::UNKNOWN_OPERATOR,
         },
         Token::MINUS => match object {
             Object::INTEGER { value } => Object::INTEGER { value: -value },
-            _ => Object::NULL,
+            _ => Object::UNKNOWN_OPERATOR,
         },
-        _ => Object::NULL,
+        _ => panic!("Prefix token not a prefix token."),
     }
 }