From 30f12dfc1f32688f377913c52b131aa78d7830b5 Mon Sep 17 00:00:00 2001
From: Preston Pan <preston@nullring.xyz>
Date: Fri, 6 Jan 2023 11:14:52 -0800
Subject: fixed stack bug; found recursion bug

---
 doc/main.nxs        |  2 ++
 src/include/stack.h |  2 ++
 src/main.c          | 22 ++++++++++++++--------
 src/stack.c         |  8 +++++++-
 src/visitor.c       |  4 +++-
 5 files changed, 28 insertions(+), 10 deletions(-)
 create mode 100644 doc/main.nxs

diff --git a/doc/main.nxs b/doc/main.nxs
new file mode 100644
index 0000000..e09c304
--- /dev/null
+++ b/doc/main.nxs
@@ -0,0 +1,2 @@
+(bind factorial (lambda (n)
+	(if (= n 0) 1 (* n (factorial (- n 1))))))
diff --git a/src/include/stack.h b/src/include/stack.h
index 5a58f0b..6b0ed9a 100644
--- a/src/include/stack.h
+++ b/src/include/stack.h
@@ -13,4 +13,6 @@ void stack_push(stack_t *s, hash_table_t *h);
 hash_table_t *stack_peek(stack_t *s);
 
 hash_table_t *stack_pop(stack_t *s);
+
+bool is_empty(stack_t *s);
 #endif
diff --git a/src/main.c b/src/main.c
index ff28829..b111ec5 100644
--- a/src/main.c
+++ b/src/main.c
@@ -78,14 +78,20 @@ int main(int argc, char **argv) {
   /* print(res); */
 
   /* DONE: TEST NON-BUILTIN FUNCTIONS (stack frame) */
-  lexer_t *lexer = init_lexer("(bind my_var 3) (bind hello (lambda (x y) (+ x "
-                              "y))) (hello (+ my_var 4) 4) (+ my_var 4)");
-  parser_t *parser = init_parser(lexer);
-  visitor_t *visitor = init_visitor(parser);
-  ast_t *root = eval(visitor);
-  print_root(root);
-  /* ast_t *res = root->subnodes[0]; */
-  /* print(res); */
+  /* lexer_t *lexer = init_lexer("(if (= (+ 3 2) 5) 1 2)"); */
+  /* parser_t *parser = init_parser(lexer); */
+  /* visitor_t *visitor = init_visitor(parser); */
+  /* ast_t *root = eval(visitor); */
+  /* print_root(root); */
+
+  /* TODO: TEST RECURSION */
+  /* lexer_t *lexer = init_lexer("(bind factorial (lambda (x) (if (<= x 0) 1 (*
+   * x" */
+  /*                             "(factorial (- x 1)))))) (factorial 3)"); */
+  /* parser_t *parser = init_parser(lexer); */
+  /* visitor_t *visitor = init_visitor(parser); */
+  /* ast_t *root = eval(visitor); */
+  /* print_root(root); */
 
   /*   lexer_t *lexer = init_lexer("((lambda (x y) (+ x y)) (+ 3 4) 4) (+ 3
    * 4)"); */
diff --git a/src/stack.c b/src/stack.c
index 2438792..ebfa640 100644
--- a/src/stack.c
+++ b/src/stack.c
@@ -26,7 +26,7 @@ void stack_push(stack_t *s, hash_table_t *h) {
 }
 /* fix heap buffer overflow */
 hash_table_t *stack_peek(stack_t *s) {
-  if (s->cur == -1)
+  if (is_empty(s))
     return NULL;
   return s->stack[s->cur];
 }
@@ -37,3 +37,9 @@ hash_table_t *stack_pop(stack_t *s) {
   s->cur--;
   return h;
 }
+
+bool is_empty(stack_t *s) {
+  if (s->cur == -1)
+    return true;
+  return false;
+}
diff --git a/src/visitor.c b/src/visitor.c
index 736ce03..5e58952 100644
--- a/src/visitor.c
+++ b/src/visitor.c
@@ -44,7 +44,7 @@ bool is_built_in(ast_t *e) {
   /* Comparison functions */
   if (strcmp(cmp, "<") == 0 || strcmp(cmp, ">") == 0 || strcmp(cmp, "=") == 0 ||
       strcmp(cmp, "<=") == 0 || strcmp(cmp, ">=") == 0 ||
-      strcmp(cmp, "eq") == 0)
+      strcmp(cmp, "eq") == 0 || strcmp(cmp, "if") == 0)
     return true;
 
   /* Type-checking */
@@ -67,6 +67,8 @@ bool is_built_in(ast_t *e) {
  * =, equal (for strings), input */
 ast_t *eval_symbol(visitor_t *v, ast_t *e) {
   /* hash_table_t *lmao = stack_peek(v->stack_frame); */
+  printf("symbol\n");
+  printf("%s\n", e->string_value);
   hash_table_t *h = stack_peek(v->stack_frame);
   if (is_built_in(e))
     return e;
-- 
cgit