1 files changed, 64 insertions, 0 deletions
diff --git a/src/linebuf.rs b/src/linebuf.rs
new file mode 100644
index 0000000..91d0306
--- /dev/null
+++ b/src/linebuf.rs
@@ -0,0 +1,64 @@
+use std::io::Write;
+use crate::cursor::*;
+
+pub struct LineBuf {
+    pre: Vec<u8>,
+    post: Vec<u8>,
+}
+
+#[allow(unused)]
+impl LineBuf {
+    pub fn new() -> Self {
+        Self {
+            pre: Vec::new(),
+            post: Vec::new(),
+        }
+    }
+
+    pub fn del_left(&mut self) -> Option<u8> {
+        self.pre.pop()
+    }
+
+    pub fn del_right(&mut self) -> Option<u8> {
+        self.post.pop()
+    }
+
+    pub fn left(&mut self) -> bool {
+        if let Some(byte) = self.del_left() {
+            self.post.push(byte);
+            true
+        } else {
+            false
+        }
+    }
+
+    pub fn right(&mut self) -> bool {
+        if let Some(byte) = self.del_right() {
+            self.pre.push(byte);
+            true
+        } else {
+            false
+        }
+    }
+
+    pub fn add(&mut self, chr: u8) {
+        self.pre.push(chr);
+    }
+
+    /// returns the whole contents of the buffer, and empties it in the process
+    pub fn dump(&mut self) -> Vec<u8> {
+        while self.right() {}
+        let mut buf = Vec::new();
+        core::mem::swap(&mut self.pre, &mut buf);
+        buf
+    }
+
+    /// TODO: kinda ugly that this is here
+    pub fn display_post(&self) {
+        for &x in self.post.iter().rev() {
+            std::io::stdout().write_all(&[x]).unwrap();
+        }
+        move_cursor(Direction::Left, self.post.len());
+        std::io::stdout().flush().unwrap();
+    }
+}