Add lexing to loops

examples/loops.reid

@@ -0,0 +1,15 @@
+// Arithmetic, function calls and imports!
+
+
+fn main() -> u32 {
+  for i in [0, 1, 2, 3, 4, 5, 6, 7, 9, 10] {
+    print("hello")
+  }
+
+  let mut num = 0;
+  while num < 10 {
+    num = num + 1;
+  }
+
+  return num;
+}

reid/src/ast/mod.rs

@@ -178,6 +178,8 @@ pub enum BlockLevelStatement {
     },
     Expression(Expression),
     Return(ReturnType, Expression),
+    ForLoop(String, Expression, Block),
+    WhileLoop(Expression, Block),
 }
 
 #[derive(Debug, Clone)]

reid/src/ast/parse.rs

@@ -231,10 +231,10 @@ impl Parse for PrimaryExpression {
                     stream.expect(Token::BracketClose)?;
                     Expression(Kind::Array(expressions), stream.get_range().unwrap())
                 }
-                _ => Err(stream.expected_err("expression inner")?)?,
+                _ => Err(stream.expecting_err("expression")?)?,
             }
         } else {
-            Err(stream.expected_err("expression")?)?
+            Err(stream.expecting_err("expression")?)?
         };
 
         while let Ok(index) = stream.parse::<ValueIndex>() {

reid/src/ast/process.rs

@@ -148,6 +148,10 @@ impl ast::Block {
                 ast::BlockLevelStatement::Return(_, e) => {
                     (StmtKind::Expression(e.process(module_id)), e.1)
                 }
+                ast::BlockLevelStatement::ForLoop(expression, expression1, block) => {
+                    todo!()
+                }
+                ast::BlockLevelStatement::WhileLoop(expression, block) => todo!(),
             };
 
             mir_statements.push(mir::Statement(kind, range.as_meta(module_id)));

reid/src/lexer.rs

@@ -42,6 +42,10 @@ pub enum Token {
     Extern,
     /// `struct`
     Struct,
+    /// `while`
+    While,
+    /// `for`
+    For,
 
     // Symbols
     /// `;`
@@ -136,6 +140,8 @@ impl ToString for Token {
             Token::Extern => String::from("extern"),
             Token::Struct => String::from("struct"),
             Token::AsKeyword => String::from("as"),
+            Token::For => String::from("for"),
+            Token::While => String::from("while"),
             Token::Semi => String::from(';'),
             Token::Equals => String::from('='),
             Token::Colon => String::from(':'),
@@ -322,6 +328,8 @@ pub fn tokenize<T: Into<String>>(to_tokenize: T) -> Result<Vec<FullToken>, Error
                     "pub" => Token::PubKeyword,
                     "struct" => Token::Struct,
                     "as" => Token::AsKeyword,
+                    "for" => Token::For,
+                    "while" => Token::While,
                     _ => Token::Identifier(value),
                 };
                 variant