refactoring key events so all Insert mode are together... may regret that later but its cleaner now. Getting delete line working

src/cg/06-textEditor.cg

@@ -18,6 +18,19 @@ textEditor = name \
 
   lines = split "\n" source;
 
+  clampCursor = state \
+    line = nth state.cursorRow state.lines ~ unwrapOr "";
+
+    newRow = max 0 state.cursorRow;
+    newRow2 = min (len state.lines - 1) newRow;
+
+    maxCol = state.mode
+      | Insert \ len line
+      | Normal \ max 0 (len line - 1);
+    newCol2 = min maxCol (max 0 state.cursorCol);
+
+    state.{ cursorRow = newRow2, cursorCol = newCol2 };
+
   write = state \
     content = join "\n" state.lines;
     { state = state, emit = [rebindAt [buffersKey, name] content] };
@@ -62,12 +75,26 @@ textEditor = name \
       state = state.{
         lines = newLines,
         cursorRow = cursorRow,
+        cursorCol = 0,
         undoStack = newUndoStack,
         mode = Insert
       },
       emit = []
     };
 
+  deleteLine = state \
+    stateSnapshot = { lines = state.lines, cursorRow = state.cursorRow, cursorCol = state.cursorCol };
+    newUndoStack = [stateSnapshot, ...state.undoStack];
+    newLines = [...(take (state.cursorRow) state.lines), ...(drop (state.cursorRow + 1) state.lines)];
+    {
+      state = clampCursor state.{
+        lines = newLines,
+        undoStack = newUndoStack,
+        pending = None
+      },
+      emit = []
+    };
+
   escape = state \ { state = state.{ mode = Normal }, emit = [] };
 
   undo = state \ state.undoStack
@@ -111,19 +138,6 @@ textEditor = name \
 
     { state = state.{ lines = newLines2, cursorCol = 0, cursorRow = state.cursorRow + 1 }, emit = [] };
 
-  clampCursor = state \
-    line = nth state.cursorRow state.lines ~ unwrapOr "";
-
-    newRow = max 0 state.cursorRow;
-    newRow2 = min (len state.lines - 1) newRow;
-
-    maxCol = state.mode
-      | Insert \ len line
-      | Normal \ max 0 (len line - 1);
-    newCol2 = min maxCol (max 0 state.cursorCol);
-
-    state.{ cursorRow = newRow2, cursorCol = newCol2 };
-
   upArrow = state \
     newState = clampCursor state.{ cursorRow = state.cursorRow - 1 };
     { state = newState, emit = [] };
@@ -186,85 +200,48 @@ textEditor = name \
           scrollY = 0,
           undoStack = [],
           redoStack = [],
-          mode = Normal # Normal | Insert | Visual
+          mode = Normal, # Normal | Insert | Visual
+          pending = None # Some "d" | Some "g" | etc.
         },
 
-        update = state event \ event
+        update = state event \ state.mode
-          | Scrolled delta \ (
+          | Insert \ (event
-            maxLineLen = fold (acc line \ max acc (len line)) 0 state.lines;
+            | Key { key = "Escape" } \ escape state
-            totalW = maxLineLen * charW * scale + maxLineLen * charGap;
+            | Key { key = "Control" } \ escape state
-            totalH = len state.lines * lineH;
+            | Key { key = "Backspace" } \ backspace state
-            newX = max 0 (min (totalW - ctx.w) (state.scrollX + delta.deltaX));
+            | Key { key = "Enter" } \ enter state
-            newY = max 0 (min (totalH - ctx.h) (state.scrollY + delta.deltaY));
+            | Key { key = k } \ insertChar k state)
-            { state = state.{ scrollY = newY, scrollX = newX }, emit = [] })
+          | Normal \ (event
+            | Scrolled delta \ (
+              maxLineLen = fold (acc line \ max acc (len line)) 0 state.lines;
+              totalW = maxLineLen * charW * scale + maxLineLen * charGap;
+              totalH = len state.lines * lineH;
+              newX = max 0 (min (totalW - ctx.w) (state.scrollX + delta.deltaX));
+              newY = max 0 (min (totalH - ctx.h) (state.scrollY + delta.deltaY));
+              { state = state.{ scrollY = newY, scrollX = newX }, emit = [] })
 
-          | Key { key = "ArrowDown" } \ withScroll (downArrow state)
+            | Key { key = "ArrowDown" } \ withScroll (downArrow state)
-          | Key { key = "j" } \ (state.mode
+            | Key { key = "j" } \ withScroll (downArrow state)
-            | Insert \ insertChar "j" state
+            | Key { key = "ArrowUp" } \ withScroll (upArrow state)
-            | Normal \ withScroll (downArrow state))
+            | Key { key = "k" } \ withScroll(upArrow state)
-
+            | Key { key = "ArrowLeft" } \ withScroll (leftArrow state)
-          | Key { key = "ArrowUp" } \ withScroll (upArrow state)
+            | Key { key = "h" } \ withScroll(leftArrow state)
-          | Key { key = "k" } \ (state.mode
+            | Key { key = "ArrowRight" } \ withScroll (rightArrow state)
-            | Insert \ insertChar "k" state
+            | Key { key = "l" } \ withScroll(rightArrow state)
-            | Normal \ withScroll(upArrow state))
+            | Key { key = "i" } \ insertMode state
-
+            | Key { key = "o" } \ openLine state
-          | Key { key = "ArrowLeft" } \ withScroll (leftArrow state)
+            | Key { key = "d", ctrl = True } \ scrollHalfDown state ctx
-          | Key { key = "h" } \ (state.mode
+            | Key { key = "u", ctrl = True } \ scrollHalfUp state ctx
-            | Insert \ insertChar "h" state
+            | Key { key = "u" } \ undo state
-            | Normal \ withScroll(leftArrow state))
+            | Key { key = "d" } \ (state.pending
-
+              | Some "d" \ deleteLine state
-          | Key { key = "ArrowRight" } \ withScroll (rightArrow state)
+              | _ \ { state = state.{ pending = Some "d" }, emit = [] })
-          | Key { key = "l" } \ (state.mode
+            | Key { key = "r", ctrl = True } \ redo state
-            | Insert \ insertChar "l" state
+            | Key { key = "W", ctrl = True, shift = True } \ write state
-            | Normal \ withScroll(rightArrow state))
+            | Key { key = "A", ctrl = True, shift = True } \ apply state
-
+            # any other key or event
-          | Key { key = "i" } \ (state.mode
+            | _ \ { state = state, emit = [] }
-            | 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
-
-          | Key { key = "u" } \ (state.mode
-            | Insert \ insertChar "u" state
-            | Normal \ undo state)
-
-          | Key { key = "r", ctrl = True } \ (state.mode
-            | Insert \ { state = state, emit = [] }
-            | Normal \ redo state)
-
-          | Key { key = "W", shift = True } \ (state.mode
-            | Insert \ insertChar "W" state
-            | Normal \ write state)
-
-          | Key { key = "W", ctrl = True, shift = True } \ (state.mode
-            | Insert \ insertChar "W" state
-            | Normal \ write state)
-
-          | Key { key = "A", ctrl = True, shift = True } \ (state.mode
-            | Insert \ insertChar "A" state
-            | Normal \ apply state)
-
-          | Key { key = "Escape" } \ escape state
-
-          | Key { key = "Backspace" } \ (state.mode
-            | Insert \ backspace state
-            | _ \ { state = state, emit = [] })
-
-          | Key { key = "Enter" } \ (state.mode
-            | Insert \ enter state
-            | _ \ { state = state, emit = [] })
-
-          # any other key
-          | Key { key = key, printable = True } \ (state.mode
-            | Insert \ insertChar key state
-            | _ \ { state = state, emit = [] })
-
-          | _ \ { state = state, emit = [] },
 
         view = state emit \
           cursorX = state.cursorCol * charW * scale + charGap * state.cursorCol;