From 49ada446f8e25ea75a8a66ea95d8c715af827c41 Mon Sep 17 00:00:00 2001
From: Daniel M <daniel.q.mueller@stud.h-da.de>
Date: Sat, 29 Jan 2022 23:29:09 +0100
Subject: [PATCH] Implement line comments

---
 README.md    |  2 +-
 src/lexer.rs | 14 ++++++++------
 src/main.rs  |  3 +--
 3 files changed, 10 insertions(+), 9 deletions(-)

diff --git a/README.md b/README.md
index d8014d7..949d385 100644
--- a/README.md
+++ b/README.md
@@ -42,7 +42,7 @@
   - [ ] If else statement `if X { ... } else { ... }`
     - [ ] If Statement
     - [ ] Else statement
-- [ ] Line comments `//`
+- [x] Line comments `//`
 - [ ] Strings
 - [ ] IO Intrinsics
   - [ ] Print
diff --git a/src/lexer.rs b/src/lexer.rs
index 5a2b577..0aedac8 100644
--- a/src/lexer.rs
+++ b/src/lexer.rs
@@ -9,7 +9,7 @@ pub enum Token {
 
     /// Identifier (name for variables, functions, ...)
     Ident(String),
-    
+
     /// Left Parenthesis ('(')
     LParen,
 
@@ -62,8 +62,8 @@ pub enum Token {
     RAngle,
 
     /// Left angle bracket Equal (<=)
-    LAngleEqu, 
-    
+    LAngleEqu,
+
     /// Left angle bracket Equal (>=)
     RAngleEqu,
 
@@ -129,7 +129,9 @@ impl<'a> Lexer<'a> {
                     self.next();
                     tokens.push(Token::LArrow);
                 }
-                
+                // Line comment. Consume every char until linefeed (next line)
+                '/' if matches!(self.peek(), '/') => while self.next() != '\n' {},
+
                 ';' => tokens.push(Token::Semicolon),
                 '+' => tokens.push(Token::Add),
                 '-' => tokens.push(Token::Sub),
@@ -169,7 +171,7 @@ impl<'a> Lexer<'a> {
                     // TODO: We only added numeric chars to the string, but the conversion could still fail
                     tokens.push(Token::I64(sval.parse().unwrap()));
                 }
-                
+
                 // Lex characters as identifier
                 ch @ ('a'..='z' | 'A'..='Z' | '_') => {
                     let mut ident = String::from(ch);
@@ -237,7 +239,7 @@ impl Token {
 
             Token::LAngle => BinOpType::Less,
             Token::LAngleEqu => BinOpType::LessEqu,
-            
+
             Token::RAngle => BinOpType::Greater,
             Token::RAngleEqu => BinOpType::GreaterEqu,
 
diff --git a/src/main.rs b/src/main.rs
index 140c190..3e5cb39 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,5 +1,3 @@
-use std::io::Write;
-
 use nek_lang::{lexer::lex, parser::parse, interpreter::Interpreter};
 
 
@@ -10,6 +8,7 @@ fn main() {
     // let mut code = String::new();
     let code = "
         a <- 5;
+        // nek-lang best lang
         a * 2;
     ";