diff --git a/include/parser.h b/include/parser.h
index b8f80f9..abb4061 100644
--- a/include/parser.h
+++ b/include/parser.h
@@ -9,9 +9,13 @@ typedef struct {
     size_t pos;
 } ASTNodeSlice;
 
-ASTNode *nud(ASTNodeSlice *slice, size_t pos);
-ASTNode *led(ASTNodeSlice *slice, size_t pos, size_t right_precedence);
+ASTNode ASTNodeSlice_peek(ASTNodeSlice slice);
+ASTNode ASTNodeSlice_next(ASTNodeSlice slice);
+
+ASTNode *nud(ASTNodeSlice *slice);
+ASTNode *led(ASTNodeSlice *slice, size_t right_precedence);
 
 size_t node_lbp(ASTNode node);
 size_t node_rbp(ASTNode node);
 AST parse(ASTNodeArray arr);
+AST parse_expr(ASTNodeSlice *arr);
diff --git a/src/parser.c b/src/parser.c
index 238cd0a..788e7de 100644
--- a/src/parser.c
+++ b/src/parser.c
@@ -2,8 +2,30 @@
 #include "lexer.h"
 #include <stdlib.h>
 
-size_t node_lbp(Operator op) {
-    switch (op) {
+size_t node_lbp(ASTNode node) {
+    if (node.type == NODE_INTEGER) {
+        return 0;
+    }
+
+    switch (node.data.binary.op) {
+        case OP_ADD:
+        case OP_SUB:
+            return 10;
+            break;
+        case OP_DIV:
+        case OP_MUL:
+            return 20;
+        default:
+            return 0;
+    }
+}
+
+size_t node_rbp(ASTNode node) {
+    if (node.type == NODE_INTEGER) {
+        return 0;
+    }
+
+    switch (node.data.binary.op) {
         case OP_ADD:
         case OP_SUB:
             return 10;
@@ -14,14 +36,4 @@ size_t node_lbp(Operator op) {
     }
 }
 
-size_t node_rbp(Operator op) {
-    switch (op) {
-        case OP_ADD:
-        case OP_SUB:
-            return 10;
-            break;
-        case OP_DIV:
-        case OP_MUL:
-            return 20;
-    }
-}
+