added byte buffer impl

src/cst/parser.rs

@@ -94,7 +94,6 @@ fn parse_constant(node: &AstNode) -> Result<CstConstantStatement, CstParserError
             name: name.ok_or(CstParserError::MissingContent { node_type: AstNodeType::StatementConstName })?.to_string(),
             atoms: atom_buff,
         }
-
     )
 }
 

src/main.rs

@@ -15,6 +15,8 @@ mod resolver;
 mod compiler;
 mod ast;
 mod cst;
+mod rst;
+mod util;
 
 fn main() {
     let compiler = HexoCompiler::new(HexoCompilerContext::new());

src/rst/mod.rs

@@ -0,0 +1 @@
+mod node;

src/rst/node.rs

@@ -0,0 +1 @@
+pub(crate) struct HexoFile {}

src/util/byte_buffer.rs

@@ -0,0 +1,72 @@
+pub(crate) struct ByteBuffer {
+    inner: Vec<u8>,
+}
+
+impl ByteBuffer {
+    pub(crate) fn new() -> Self {
+        ByteBuffer {
+            inner: Vec::new()
+        }
+    }
+
+    pub(crate) fn push_byte(&mut self, byte: u8) {
+        self.inner.push(byte);
+    }
+
+    pub(crate) fn push_string(&mut self, string: String) {
+        self.inner.extend_from_slice(string.as_bytes());
+    }
+
+    pub(crate) fn push_u32(&mut self, num: u32) {
+        self.inner.extend_from_slice(num.to_be_bytes().as_slice());
+    }
+
+    pub(crate) fn len(&self) -> usize {
+        self.inner.len()
+    }
+
+    pub(crate) fn as_vec(&self) -> Vec<u8> {
+        self.inner.clone()
+    }
+}
+
+mod test {
+    use crate::util::ByteBuffer;
+
+    #[test]
+    fn byte_push() {
+        let mut buffer = ByteBuffer::new();
+        buffer.push_byte(0x01);
+        buffer.push_byte(0x02);
+
+        assert_eq!(buffer.len(), 2);
+
+        assert_eq!(buffer.as_vec(), vec![0x01, 0x02]);
+    }
+
+    #[test]
+    fn string_push() {
+        let mut buffer = ByteBuffer::new();
+        buffer.push_string("hello world".to_string());
+
+        assert_eq!(buffer.len(), 11);
+
+        assert_eq!(
+            buffer.as_vec(),
+            vec![104, 101, 108, 108, 111, 32, 119, 111, 114, 108, 100]
+        );
+    }
+
+    #[test]
+    fn u32_push() {
+        let mut buffer = ByteBuffer::new();
+        buffer.push_u32(13);
+
+        assert_eq!(buffer.len(), 4);
+
+        assert_eq!(
+            buffer.as_vec(),
+            vec![0, 0, 0, 13]
+        );
+    }
+}

src/util/mod.rs

@@ -0,0 +1,3 @@
+mod byte_buffer;
+
+pub(crate) use byte_buffer::ByteBuffer;