From 7a97ec3f90d7b08e047b1bb72c012acf83e37b01 Mon Sep 17 00:00:00 2001
From: Dustin Swan <dustin@dustinswan.com>
Date: Wed, 4 Mar 2026 17:56:53 -0700
Subject: [PATCH] texteditor. 'o' key

---
 src/cg/01-stdlib.cg     | 10 ++++++++++
 src/cg/06-textEditor.cg | 20 ++++++++++++++++++++
 2 files changed, 30 insertions(+)

diff --git a/src/cg/01-stdlib.cg b/src/cg/01-stdlib.cg
index cfb63bf..b05de06 100644
--- a/src/cg/01-stdlib.cg
+++ b/src/cg/01-stdlib.cg
@@ -77,6 +77,16 @@ join = s list \ list
   | [x] \ x
   | [x, ...xs] \ (x & s & (join s xs));
 
+# repeatStr : Int \ String \ String
+repeatStr = n str \ n
+  | 0 \ ""
+  | m \ str & (repeatStr (m - 1) str);
+
+# repeat : Int \ a \ List a
+repeat = n a \ n
+  | 0 \ []
+  | m \ [a, ...repeat (m - 1) a];
+
 # zipWith : (a \ b \ c) \ List a \ List b \ List c
 zipWith = f l1 l2 \ l1
   | [] \ []
diff --git a/src/cg/06-textEditor.cg b/src/cg/06-textEditor.cg
index c626821..81de2ca 100644
--- a/src/cg/06-textEditor.cg
+++ b/src/cg/06-textEditor.cg
@@ -52,6 +52,22 @@ textEditor = name \
       emit = []
     };
 
+  # 'o' key
+  openLine = state \
+    stateSnapshot = { lines = state.lines, cursorRow = state.cursorRow, cursorCol = state.cursorCol };
+    newUndoStack = [stateSnapshot, ...state.undoStack];
+    cursorRow = state.cursorRow + 1;
+    newLines = insertAt cursorRow "" state.lines;
+    {
+      state = state.{
+        lines = newLines,
+        cursorRow = cursorRow,
+        undoStack = newUndoStack,
+        mode = Insert
+      },
+      emit = []
+    };
+
   escape = state \ { state = state.{ mode = Normal }, emit = [] };
 
   undo = state \ state.undoStack
@@ -206,6 +222,10 @@ textEditor = name \
             | Insert \ insertChar "i" state
             | Normal \ insertMode state)
 
+          | Key { key = "o" } \ (state.mode
+            | Insert \ insertChar "o" state
+            | Normal \ openLine state)
+
           | Key { key = "d", ctrl = True } \ scrollHalfDown state ctx
           | Key { key = "u", ctrl = True } \ scrollHalfUp state ctx