From 92d142b9cf213b9c2b533bf523d2886002b24a03 Mon Sep 17 00:00:00 2001
From: LaEntropiaa <aadrian887mh@gmail.com>
Date: Wed, 25 Mar 2026 11:30:12 -0600
Subject: [PATCH] It works, basic but works, need to move out logic to places,
 like ASTNode array shouldn't be on the lexer or future logic for fractions
 and error handling in the evaluator. Just the things at the top of my head

---
 include/evaluator.h   |  9 +++++++++
 include/parser.h      |  4 ++++
 src/evaluator.c       | 22 ++++++++++++++++++++++
 test/test_evaluator.c | 32 ++++++++++++++++++++++++++++++++
 test/test_parser.c    | 28 ----------------------------
 5 files changed, 67 insertions(+), 28 deletions(-)
 create mode 100644 test/test_evaluator.c

diff --git a/include/evaluator.h b/include/evaluator.h
index e69de29..8e1ea47 100644
--- a/include/evaluator.h
+++ b/include/evaluator.h
@@ -0,0 +1,9 @@
+#ifndef EVALUATOR_H
+#define EVALUATOR_H
+
+#include "lexer.h"
+#include <stdint.h>
+
+uint64_t evaluate(ASTNode *tree);
+
+#endif // !EVALUATOR_H
diff --git a/include/parser.h b/include/parser.h
index 64f5df4..911d964 100644
--- a/include/parser.h
+++ b/include/parser.h
@@ -1,3 +1,6 @@
+#ifndef PARSER_H
+#define PARSER_H
+
 #include "lexer.h"
 #include <stdint.h>
 
@@ -23,3 +26,4 @@ uint8_t node_rbp(ASTNode node);
 AST parse(ASTNodeArray *arr);
 ASTNode *parse_expr(ASTNodeSlice *slice, uint8_t min_bp);
 
+#endif // !PARSER_H
diff --git a/src/evaluator.c b/src/evaluator.c
index e69de29..fc0048d 100644
--- a/src/evaluator.c
+++ b/src/evaluator.c
@@ -0,0 +1,22 @@
+#include "evaluator.h"
+#include "lexer.h"
+#include <stdint.h>
+
+uint64_t evaluate(ASTNode *tree) {
+    if (tree->type == NODE_BINARY_OP) {
+        switch (tree->data.binary.op) {
+            case OP_ADD:
+                return evaluate(tree->data.binary.left) + evaluate(tree->data.binary.left);
+            case OP_SUB:
+                return evaluate(tree->data.binary.left) - evaluate(tree->data.binary.left);
+            case OP_MUL:
+                return evaluate(tree->data.binary.left) * evaluate(tree->data.binary.left);
+            case OP_DIV:
+                return evaluate(tree->data.binary.left) / evaluate(tree->data.binary.left);
+
+        }
+    } else {
+        return tree->data.integer;
+    }
+}
+
diff --git a/test/test_evaluator.c b/test/test_evaluator.c
new file mode 100644
index 0000000..cf97930
--- /dev/null
+++ b/test/test_evaluator.c
@@ -0,0 +1,32 @@
+#include "lexer.h"
+#include "parser.h"
+#include "evaluator.h"
+#include <stdarg.h>
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <setjmp.h>
+#include <cmocka.h>
+#include <stdlib.h>
+
+static void test_basic_evaluation(void** state) {
+    (void) state;
+
+    char expr[256] = "2 + 4 * 40 / 2";
+    ASTNodeArray context;
+
+    tokenize(expr, &context);
+    AST tree = parse(&context);
+    uint64_t value = evaluate(tree.head);
+
+    assert_int_equal(value, 82);
+}
+
+int main(void) {
+    const struct CMUnitTest tests[] = {
+        cmocka_unit_test(test_basic_evaluation),
+    };
+
+    cmocka_run_group_tests(tests, NULL, NULL);
+    return EXIT_SUCCESS;
+}
diff --git a/test/test_parser.c b/test/test_parser.c
index 70e550d..83a6592 100644
--- a/test/test_parser.c
+++ b/test/test_parser.c
@@ -17,34 +17,6 @@ static void test_parsing_basic_expression(void **state) {
     assert_int_equal(tokenize(expr, &tokens), LEXER_OK);
     assert_int_equal(tokens.len, 7);
 
-    ASTNodeArray_get(&tokens, 0, &node);
-    assert_int_equal(node.type, NODE_INTEGER);
-    assert_int_equal(node.data.integer, 2);
-
-    ASTNodeArray_get(&tokens, 1, &node);
-    assert_int_equal(node.type, NODE_BINARY_OP);
-    assert_int_equal(node.data.binary.op, OP_ADD);
-
-    ASTNodeArray_get(&tokens, 2, &node);
-    assert_int_equal(node.type, NODE_INTEGER);
-    assert_int_equal(node.data.integer, 3);
-
-    ASTNodeArray_get(&tokens, 3, &node);
-    assert_int_equal(node.type, NODE_BINARY_OP);
-    assert_int_equal(node.data.binary.op, OP_DIV);
-
-    ASTNodeArray_get(&tokens, 4, &node);
-    assert_int_equal(node.type, NODE_INTEGER);
-    assert_int_equal(node.data.integer, 66);
-
-    ASTNodeArray_get(&tokens, 5, &node);
-    assert_int_equal(node.type, NODE_BINARY_OP);
-    assert_int_equal(node.data.binary.op, OP_MUL);
-
-    ASTNodeArray_get(&tokens, 6, &node);
-    assert_int_equal(node.type, NODE_INTEGER);
-    assert_int_equal(node.data.integer, 789);
-
     AST tree = parse(&tokens);
     // Assert head is +
     assert_int_equal(tree.head->type, NODE_BINARY_OP);