Allow pub-keyword for impl-block

examples/hello_world_harder.reid

@@ -1,5 +1,4 @@
 import std::print;
-import std::from_str;
 import std::add_char;
 import std::set_char;
 import std::free_string;
@@ -8,7 +7,7 @@ import std::add_num_to_str;
 import std::concat_strings;
 
 fn main() {
-    let mut test = from_str("hello");
+    let mut test = String::new();
 
     concat_strings(&mut test, from_str(" world"));
 

reid/lib/std.reid

@@ -11,6 +11,17 @@ struct String {
     must_be_freed: bool,
 }
 
+impl String {
+    pub fn new() -> String {
+        String {
+            inner: char::alloca(0),
+            length: 0,
+            max_length: 0,
+            must_be_freed: true,
+        }
+    }
+}
+
 impl binop (lhs: String) + (rhs: *char) -> String {
     let mut new = lhs;
     let added = from_str(rhs);

reid/src/ast/parse.rs

@@ -1052,7 +1052,9 @@ impl Parse for AssociatedFunctionBlock {
         let ty = stream.parse::<Type>()?;
         stream.expect(Token::BraceOpen)?;
         let mut functions = Vec::new();
-        while let Some(Token::FnKeyword) = stream.peek() {
+        loop {
+            match stream.peek() {
+                Some(Token::FnKeyword) | Some(Token::PubKeyword) => {
                     let mut fun: FunctionDefinition = stream.parse()?;
                     fun.0.self_kind = match fun.0.self_kind {
                         SelfKind::Owned(_) => SelfKind::Owned(ty.0.clone()),
@@ -1062,6 +1064,9 @@ impl Parse for AssociatedFunctionBlock {
                     };
                     functions.push(fun);
                 }
+                _ => break,
+            }
+        }
 
         stream.expect(Token::BraceClose)?;
         Ok(AssociatedFunctionBlock(ty, functions))