From 1079eb1671a4d418900a41d8664fa8b1a0d1c6b2 Mon Sep 17 00:00:00 2001
From: Daniel M <daniel.q.mueller@stud.h-da.de>
Date: Sat, 29 Jan 2022 21:26:14 +0100
Subject: [PATCH] Implement bitwise not

---
 README.md          |  2 +-
 src/interpreter.rs |  1 +
 src/lexer.rs       |  4 ++++
 src/parser.rs      | 10 +++++++++-
 4 files changed, 15 insertions(+), 2 deletions(-)

diff --git a/README.md b/README.md
index ccc2d84..39f48ab 100644
--- a/README.md
+++ b/README.md
@@ -30,7 +30,7 @@
     - [x] Bitwise AND `X&Y`
     - [x] Bitwise OR `X|Y`
     - [x] Bitwise XOR `X^Y`
-    - [ ] Bitwise NOT `~X`
+    - [x] Bitwise NOT `~X`
     - [x] Bitwise left shift `X<<Y`
     - [x] Bitwise right shift `X>>Y`
 - [ ] Variables
diff --git a/src/interpreter.rs b/src/interpreter.rs
index 3899908..64f4498 100644
--- a/src/interpreter.rs
+++ b/src/interpreter.rs
@@ -33,6 +33,7 @@ impl Interpreter {
 
         match (operand, uo) {
             (Value::I64(val), UnOpType::Negate) => Value::I64(-val),
+            (Value::I64(val), UnOpType::BNot) => Value::I64(!val),
             // _ => panic!("Value type is not compatible with unary operation"),
         }
     }
diff --git a/src/lexer.rs b/src/lexer.rs
index 042ea8b..f28bf6c 100644
--- a/src/lexer.rs
+++ b/src/lexer.rs
@@ -43,6 +43,9 @@ pub enum Token {
     /// Shift Right (>>)
     Shr,
 
+    /// Tilde (~)
+    Tilde,
+
     /// End of file
     EoF,
 }
@@ -107,6 +110,7 @@ impl<'a> Lexer<'a> {
                 '^' => tokens.push(Token::BXor),
                 '(' => tokens.push(Token::LParen),
                 ')' => tokens.push(Token::RParen),
+                '~' => tokens.push(Token::Tilde),
 
                 //TODO: Don't panic, keep calm
                 _ => panic!("Lexer encountered unexpected char: '{}'", ch),
diff --git a/src/parser.rs b/src/parser.rs
index 54debc9..11f9e96 100644
--- a/src/parser.rs
+++ b/src/parser.rs
@@ -40,6 +40,9 @@ pub enum BinOpType {
 pub enum UnOpType {
     /// Unary Negate
     Negate,
+
+    /// Bitwise Not
+    BNot,
 }
 
 #[derive(Debug, PartialEq, Eq, Clone)]
@@ -55,7 +58,7 @@ pub enum Ast {
 /*
 ## Grammar
 ### Expressions
-expr_primary = LITERAL | "(" expr p | "-" expr_primary
+expr_primary = LITERAL | "(" expr p | "-" expr_primary | "~" expr_primary
 expr_mul = expr_primary (("*" | "/" | "%") expr_primary)*
 expr_add = expr_mul (("+" | "-") expr_mul)*
 expr_shift = expr_add ((">>" | "<<") expr_add)*
@@ -137,6 +140,11 @@ impl<T: Iterator<Item = Token>> Parser<T> {
                 Ast::UnOp(UnOpType::Negate, operand.into())
             }
 
+            Token::Tilde => {
+                let operand = self.parse_primary();
+                Ast::UnOp(UnOpType::BNot, operand.into())
+            }
+
             tok => panic!("Error parsing primary expr: Unexpected Token '{:?}'", tok),
         }
     }