Getting vim motion architecture started. deleteWord added. Changing deleteLine to use it.

src/cg/06-textEditor.cg

@@ -31,6 +31,59 @@ textEditor = name \
 
     state.{ cursorRow = newRow2, cursorCol = newCol2 };
 
+  charKind = ch \
+    ch == " " | True \ Space
+    | False \ (isWordChar ch
+      | True \ Word
+      | False \ Punct);
+
+  skipWhile = pred lines row col \
+    line = nth row lines ~ unwrapOr "";
+    col >= len line
+    | True \ (row + 1 < len lines
+      | True \ skipWhile pred lines (row + 1) 0
+      | False \ { row = row, col = col })
+    | False \ (pred (nth col line ~ unwrapOr "")
+      | True \ skipWhile pred lines row (col + 1)
+      | False \ { row = row, col = col });
+
+  nextWordStart = lines row col \
+    line = nth row lines ~ unwrapOr "";
+    kind = charKind (nth col line ~ unwrapOr " ");
+    pos = skipWhile (ch \ charKind ch == kind) lines row col;
+    skipWhile (ch \ ch == " ") lines pos.row pos.col;
+
+  resolveMotion = motion state \
+    from = { row = state.cursorRow, col = state.cursorCol };
+    to = motion
+      | Word \ nextWordStart state.lines from.row from.col
+      | WholeLine \ from;
+    { from = from, to = to };
+
+  deleteLine = state \
+    newLines = [...(take (state.cursorRow) state.lines), ...(drop (state.cursorRow + 1) state.lines)];
+    { state = state.{ lines = newLines, emit = [] } };
+
+  deleteRange = state from to \
+    line = nth from.row state.lines ~ unwrapOr "";
+    toCol = to.row > from.row
+      | True \ len line
+      | False \ to.col;
+    newLine = (slice line 0 from.col) & (slice line toCol (len line));
+    state.{ lines = updateAt from.row (_ \ newLine) state.lines, cursorCol = from.col };
+
+  applyOperator = operator motion state \
+    target = resolveMotion motion state;
+    stateSnapshot = { lines = state.lines, cursorRow = state.cursorRow, cursorCol = state.cursorCol };
+    newState = operator
+      | Delete \ (motion
+        | WholeLine \ deleteLine state
+        | _ \ { state = deleteRange state target.from target.to, emit = [] });
+    { state = clampCursor newState.state.{ undoStack = [stateSnapshot, ...state.undoStack], pending = None }, emit = newState.emit };
+
+  moveCursor = motion state \
+    state.{ cursorCol = motion.to.col, cursorRow = motion.to.row };
+
   write = state \
     content = join "\n" state.lines;
     { state = state, emit = [rebindAt [buffersKey, name] content] };
@@ -82,19 +135,6 @@ textEditor = name \
       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
@@ -233,10 +273,13 @@ textEditor = name \
             | Key { key = "d", ctrl = True } \ scrollHalfDown state ctx
             | Key { key = "u", ctrl = True } \ scrollHalfUp state ctx
             | Key { key = "u" } \ undo state
-            | Key { key = "d" } \ (state.pending
-              | Some "d" \ deleteLine state
-              | _ \ { state = state.{ pending = Some "d" }, emit = [] })
             | Key { key = "r", ctrl = True } \ redo state
+            | Key { key = "d" } \ (state.pending
+              | Some Delete \ applyOperator Delete WholeLine state
+              | _ \ { state = state.{ pending = Some Delete }, emit = [] })
+            | Key { key = "w" } \ (state.pending
+              | None \ withScroll { state = moveCursor (resolveMotion Word state) state, emit = [] }
+              | Some Delete \ withScroll (applyOperator Delete Word state))
             | Key { key = "W", ctrl = True, shift = True } \ write state
             | Key { key = "A", ctrl = True, shift = True } \ apply state
             # any other key or event

src/cg/10-os.cg

@@ -107,7 +107,7 @@ os =
                         ui.rect { w = titleBarHeight, h = titleBarHeight, color = "rgba(255,255,255,0.2)" },
                         # button text
                         ui.positioned {
-                          x = 10, y = 5, child = text "x"
+                          x = 12, y = 5, child = text "x"
                         }
                       ]
                     }